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  • 1.
    Alagumalai, Vasudevan
    et al.
    Department of Mechanical Engineering, Saveetha School of Engineering, SIMATS, Chennai 602105, India.
    Shanmugam, Vigneshwaran
    Department of Mechanical Engineering, Saveetha School of Engineering, SIMATS, Chennai 602105, India.
    Balasubramanian, Navin Kumar
    Department of Mechanical Engineering, Saveetha School of Engineering, SIMATS, Chennai 602105, India.
    Krishnamoorthy, Yoganandam
    Department of Mechanical Engineering, ARM College of Engineering and Technology, Kanchipuram 603209, India.
    Ganesan, Velmurugan
    Department of Agricultural Engineering, Saveetha School of Engineering, SIMATS, Chennai 602105, India.
    Försth, Michael
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Berto, Filippo
    Department of Mechanical Engineering, Norwegian University of Science and Technology, 13 7491 Trondheim, Norway.
    Chanda, Avishek
    Centre for Advanced Composite Materials, Department of Mechanical Engineering, The University of Auckland, Auckland 1142, New Zealand.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Impact response and damage tolerance of hybrid glass/kevlar-fibre epoxy structural composites2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 16Article in journal (Refereed)
    Abstract [en]

    The present study is aimed at investigating the effect of hybridisation on Kevlar/E-Glass based epoxy composite laminate structures. Composites with 4 mm thickness and 16 layers of fibre (14 layers of E-glass centred and 2 outer layers of Kevlar) were fabricated using compression moulding technique. The fibre orientation of the Kevlar layers had 3 variations (0, 45 and 60°), whereas the E-glass fibre layers were maintained at 0° orientation. Tensile, flexural, impact (Charpy and Izod), interlaminar shear strength and ballistic impact tests were conducted. The ballistic test was performed using a gas gun with spherical hard body projectiles at the projectile velocity of 170 m/s. The pre-and post-impact velocities of the projectiles were measured using a high-speed camera. The energy absorbed by the composite laminates was further reported during the ballistic test, and a computerised tomographic scan was used to analyse the impact damage. The composites with 45° fibre orientation of Kevlar fibres showed better tensile strength, flexural strength, Charpy impact strength, and energy absorption. The energy absorbed by the composites with 45° fibre orientation was 58.68 J, which was 14% and 22% higher than the 0° and 60° oriented composites. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

  • 2.
    Alinejad, M.
    et al.
    Department of Forestry, Michigan State University, East Lansing, United States.
    Henry, C.
    Department of Forestry, Michigan State University, East Lansing, United States.
    Nikafshar, S.
    Department of Forestry, Michigan State University, East Lansing, United States.
    Gondaliya, A.
    Chemical Engineering and Materials Science, Michigan State University, East Lansing, United States.
    Bagheri, B.
    Chemical Engineering and Materials Science, Michigan State University, East Lansing, United States.
    Chen, N.
    Eastern Regional Research Center, USDA-ARS, Wyndmoor, United States.
    Singh, S.K.
    Chemical and Biological Engineering, Montana State University, Bozeman, United States.
    Hodge, David
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Nejad, M.
    Department of Forestry, Michigan State University, East Lansing, United States. Chemical Engineering and Materials Science, Michigan State University, East Lansing, United States..
    Lignin-based polyurethanes: Opportunities for bio-based foams, elastomers, coatings and adhesives2019In: Polymers, E-ISSN 2073-4360, Vol. 11, no 7, article id 1202Article in journal (Refereed)
    Abstract [en]

    Polyurethane chemistry can yield diverse sets of polymeric materials exhibiting a widerange of properties for various applications and market segments. Utilizing lignin as a polyol presentsan opportunity to incorporate a currently underutilized renewable aromatic polymer into theseproducts. In this work, we will review the current state of technology for utilizing lignin as a polyolreplacement in different polyurethane products. This will include a discussion of lignin structure,diversity, and modification during chemical pulping and cellulosic biofuels processes, approachesfor lignin extraction, recovery, fractionation, and modification/functionalization. We will discussthe potential of incorporation of lignins into polyurethane products that include rigid and flexiblefoams, adhesives, coatings, and elastomers. Finally, we will discuss challenges in incorporating ligninin polyurethane formulations, potential solutions and approaches that have been taken to resolvethose issues.

  • 3.
    Alrifaiy, Ahmed
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Lindahl, Olof
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Ramser, Kerstin
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Polymer-based microfluidic devices for pharmacy, biology and tissue engineering2012In: Polymers, E-ISSN 2073-4360, Vol. 4, no 3, p. 1349-1398Article in journal (Refereed)
    Abstract [en]

    This paper reviews microfluidic technologies with emphasis on applications in the fields of pharmacy, biology, and tissue engineering. Design and fabrication of microfluidic systems are discussed with respect to specific biological concerns, such as biocompatibility and cell viability. Recent applications and developments on genetic analysis, cell culture, cell manipulation, biosensors, pathogen detection systems, diagnostic devices, high-throughput screening and biomaterial synthesis for tissue engineering are presented. The pros and cons of materials like polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polystyrene (PS), polycarbonate (PC), cyclic olefin copolymer (COC), glass, and silicon are discussed in terms of biocompatibility and fabrication aspects. Microfluidic devices are widely used in life sciences. Here, commercialization and research trends of microfluidics as new, easy to use, and cost-effective measurement tools at the cell/tissue level are critically reviewed.

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  • 4.
    Aqrawe, Zaid
    et al.
    Department of Anatomy & Medical Imaging, School of Medical Sciences, University of Auckland, Auckland 1023, New Zealand.
    Boehler, Christian
    Department of Microsystems Engineering (IMTEK) and BrainLinks-BrainTools Center, University of Freiburg, 79110 Freiburg, Germany.
    Bansal, Mahima
    School of Pharmacy, University of Auckland, Auckland 1023, New Zealand.
    O’Carroll, Simon J.
    Department of Anatomy & Medical Imaging, School of Medical Sciences, University of Auckland, Auckland 1023, New Zealand.
    Asplund, Maria
    Luleå University of Technology, Department of Health Sciences, Nursing and Medical technology. Department of Microsystems Engineering (IMTEK) and BrainLinks-BrainTools Center, University of Freiburg, 79110 Freiburg, Germany.
    Svirskis, Darren
    School of Pharmacy, University of Auckland, Auckland 1023, New Zealand.
    Stretchable Electronics Based on Laser Structured, Vapor Phase Polymerized PEDOT/Tosylate2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 8, article id 1654Article in journal (Refereed)
    Abstract [en]

    The fabrication of stretchable conductive material through vapor phase polymerization of poly(3,4-ethylenedioxythiophene) (PEDOT) is presented alongside a method to easily pattern these materials with nanosecond laser structuring. The devices were constructed from sheets of vapor phase polymerized PEDOT doped with tosylate on pre-stretched elastomeric substrates followed by laser structuring to achieve the desired geometrical shape. Devices were characterized for electrical conductivity, morphology, and electrical integrity in response to externally applied strain. Fabricated PEDOT sheets displayed a conductivity of 53.1 ± 1.2 S cm−1; clear buckling in the PEDOT microstructure was observed as a result of pre-stretching the underlying elastomeric substrate; and the final stretchable electronic devices were able to remain electrically conductive with up to 100% of externally applied strain. The described polymerization and fabrication steps achieve highly processable and patternable functional conductive polymer films, which are suitable for stretchable electronics due to their ability to withstand externally applied strains of up to 100%.

  • 5.
    Babu, Karthik
    et al.
    Center for Polymer Composites and Natural Fiber Research, Tamil Nadu 625005, India.
    Rendén, Gabriella
    Department of Fibre and Polymer Technology, Polymeric Materials Division, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
    Afriyie Mensah, Rhoda
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Kim, Nam Kyeun
    Centre for Advanced Composite Materials, Department of Mechanical Engineering, University of Auckland, Auckland 1142, New Zealand.
    Jiang, Lin
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Xu, Qiang
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Restás, Ágoston
    Department of Fire Protection and Rescue Control, National University of Public Service, H-1011 Budapest, Hungary.
    Esmaeely Neisiany, Rasoul
    Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran.
    Hedenqvist, Mikael S.
    Department of Fibre and Polymer Technology, Polymeric Materials Division, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
    Försth, Michael
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Byström, Alexandra
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Das, Oisik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    A Review on the Flammability Properties of Carbon-Based Polymeric Composites: State-of-the-Art and Future Trends2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 7, article id 1518Article, review/survey (Refereed)
    Abstract [en]

    Carbon based fillers have attracted a great deal of interest in polymer composites because of their ability to beneficially alter properties at low filler concentration, good interfacial bonding with polymer, availability in different forms, etc. The property alteration of polymer composites makes them versatile for applications in various fields, such as constructions, microelectronics, biomedical, and so on. Devastations due to building fire stress the importance of flame-retardant polymer composites, since they are directly related to human life conservation and safety. Thus, in this review, the significance of carbon-based flame-retardants for polymers is introduced. The effects of a wide variety of carbon-based material addition (such as fullerene, CNTs, graphene, graphite, and so on) on reaction-to-fire of the polymer composites are reviewed and the focus is dedicated to biochar-based reinforcements for use in flame retardant polymer composites. Additionally, the most widely used flammability measuring techniques for polymeric composites are presented. Finally, the key factors and different methods that are used for property enhancement are concluded and the scope for future work is discussed.

  • 6.
    Budtova, Tatiana
    et al.
    MINES ParisTech, Center for Materials Forming (CEMEF), PSL Research University, UMR CNRS 7635, CS 10207, 06904 Sophia Antipolis, France.
    Aguilera, Daniel Antonio
    MINES ParisTech, Center for Materials Forming (CEMEF), PSL Research University, UMR CNRS 7635, CS 10207, 06904 Sophia Antipolis, France.
    Beluns, Sergejs
    Faculty of Materials Science and Applied Chemistry, Institute of Polymer Materials, Riga Technical University, P.Valdena 3/7, LV, 1048 Riga, Latvia.
    Berglund, Linn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Chartier, Coraline
    MINES ParisTech, Center for Materials Forming (CEMEF), PSL Research University, UMR CNRS 7635, CS 10207, 06904 Sophia Antipolis, France.
    Espinosa, Eduardo
    Bioagres Group, Chemical Engineering Department, Faculty of Science, Universidad de Córdoba, Campus of Rabanales, 14014 Córdoba, Spain.
    Gaidukovs, Sergejs
    Faculty of Materials Science and Applied Chemistry, Institute of Polymer Materials, Riga Technical University, P.Valdena 3/7, LV, 1048 Riga, Latvia.
    Klimek-Kopyra, Agnieszka
    Department of Agroecology and Plant Production, Faculty of Agriculture and Economics, University of Agriculture, Aleja Mickieiwcza 21, 31-120 Kraków, Poland.
    Kmita, Angelika
    Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow, Poland.
    Lachowicz, Dorota
    Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow, Poland.
    Liebner, Falk
    Department of Chemistry, Institute for Chemistry of Renewable Resources, University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad Lorenz Straße 24, A-3430 Tulln an der Donau, Austria.
    Platnieks, Oskars
    Faculty of Materials Science and Applied Chemistry, Institute of Polymer Materials, Riga Technical University, P.Valdena 3/7, LV, 1048 Riga, Latvia.
    Rodríguez, Alejandro
    Bioagres Group, Chemical Engineering Department, Faculty of Science, Universidad de Córdoba, Campus of Rabanales, 14014 Córdoba, Spain.
    Tinoco Navarro, Lizeth Katherine
    CEITEC-VUT Central European Institute of Technology—Brno university of Technology, Purkyňova 123, 612 00 Brno-Královo Pole, Czech Republic.
    Zou, Fangxin
    MINES ParisTech, Center for Materials Forming (CEMEF), PSL Research University, UMR CNRS 7635, CS 10207, 06904 Sophia Antipolis, France.
    Buwalda, Sytze J.
    MINES ParisTech, Center for Materials Forming (CEMEF), PSL Research University, UMR CNRS 7635, CS 10207, 06904 Sophia Antipolis, France.
    Biorefinery Approach for Aerogels2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 12, article id 2779Article, review/survey (Refereed)
    Abstract [en]

    According to the International Energy Agency, biorefinery is “the sustainable processing of biomass into a spectrum of marketable bio-based products (chemicals, materials) and bioenergy (fuels, power, heat)”. In this review, we survey how the biorefinery approach can be applied to highly porous and nanostructured materials, namely aerogels. Historically, aerogels were first developed using inorganic matter. Subsequently, synthetic polymers were also employed. At the beginning of the 21st century, new aerogels were created based on biomass. Which sources of biomass can be used to make aerogels and how? This review answers these questions, paying special attention to bio-aerogels’ environmental and biomedical applications. The article is a result of fruitful exchanges in the frame of the European project COST Action “CA 18125 AERoGELS: Advanced Engineering and Research of aeroGels for Environment and Life Sciences”.

  • 7.
    Das, Oisik
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Ramakrishna, Seeram
    Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore.
    Education and Research during Pandemics: Illustrated by the Example of Experimental Biocomposites Research2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 8, article id 1848Article in journal (Other academic)
  • 8.
    Dvořák, Ondřej
    et al.
    Department of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 1176, 165 00 Prague, Czech Republic.
    Kvietková, Monika Sarvašová
    Department of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 1176, 165 00 Prague, Czech Republic.
    Šimůnková, Kristýna
    Department of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 1176, 165 00 Prague, Czech Republic.
    Machanec, Ondřej
    Department of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 1176, 165 00 Prague, Czech Republic.
    Pánek, Miloš
    Department of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 1176, 165 00 Prague, Czech Republic.
    Pastierovič, Filip
    Department of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 1176, 165 00 Prague, Czech Republic.
    Lin, Chia-Feng
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Jones, Dennis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering. Department of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 1176, 165 00 Prague, Czech Republic.
    The Influence of the Initial Treatment of Oak Wood on Increasing the Durability of Exterior Transparent Coating Systems2023In: Polymers, E-ISSN 2073-4360, Vol. 15, no 15, article id 3251Article in journal (Refereed)
    Abstract [en]

    This study determined the impact of undertaking an initial treatment of oak wood by sealing its surface pores with epoxy resin, focusing on the durability of transparent coating systems when exposed outdoors. Throughout the exposure period, various parameters including color, gloss, surface wettability, and both macroscopic and microscopic surface evaluation were continuously monitored. The study involved two sets of samples: one set underwent the pretreatment, while the other did not. Subsequently, four coating systems were applied to the samples, comprising two solvent-based and two water-based coatings. The experiment was conducted over a period of two years, utilizing natural weathering methods within the premises of the Czech University of Life Sciences in Prague. The pretreatment with epoxy resin exhibited enhanced durability for all paint systems. The analysis showed a significant difference in gloss and color after 12 months of weathering exposure without any significant effect on surface wettability and sealing. However, after 24 months of the weathering exposure, no significant differences between the sealed and unsealed surface were observed. The most significant change in properties was noted for the water-based coatings used in coating systems number 3 and 4, and these coatings were rated as the best.

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  • 9.
    Ganesan, Velmurugan
    et al.
    Department of Agricultural Engineering, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai 602105, India.
    Shanmugam, Vigneshwaran
    Department of Mechanical Engineering, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai 602105, India.
    Kaliyamoorthy, Babu
    Department of Mechanical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Chennai 603110, India.
    Sanjeevi, Sekar
    Department of Mechanical Engineering, Hindusthan Institute of Technology, Coimbatore 641028, India.
    Shanmugam, Suresh Kumar
    Faculty of Mechanical Engineering, Kalasalingam Academy of Research and Education, Krishnankoil 626128, India.
    Alagumalai, Vasudevan
    Department of Mechanical Engineering, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai 602105, India.
    Krishnamoorthy, Yoganandam
    Department of Mechanical Engineering, ARM College of Engineering and Technology, Chennai 602105, India.
    Försth, Michael
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Razavi, Seyed Mohammad Javad
    Department of Mechanical Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Optimisation of Mechanical Properties in Saw-Dust/Woven-Jute Fibre/Polyester Structural Composites under Liquid Nitrogen Environment Using Response Surface Methodology2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 15, article id 2471Article in journal (Refereed)
    Abstract [en]

    Natural fibre-based composites are replacing traditional materials in a wide range of structural applications that are used in different environments. Natural fibres suffer from thermal shocks, which affects the use of these composites in cold environment. Considering these, a goal was set in the present research to investigate the impact of cryogenic conditions on natural fibre composites. Composites were developed using polyester as matrix and jute-fibre and waste Teak saw-dust as reinforcement and filler, respectively. The effects of six parameters, viz., density of saw-dust, weight ratio of saw-dust, grade of woven-jute, number of jute layers, duration of cryogenic treatment of composite and duration of alkaline treatment of fibres on the mechanical properties of the composite was evaluated with an objective to maximise hardness, tensile, impact and flexural strengths. Taguchi method was used to design the experiments and response-surface methodology was used to model, predict and plot interactive surface plots. Results indicated that the duration of cryogenic treatment had a significant effect on mechanical properties, which was better only up to 60 min. The models were found to be statistically significant. The study concluded that saw-dust of density 300 kg/m(3) used as a filler with a weight ratio of 13 wt.% and a reinforcement of a single layer of woven-jute-fibre mat of grade 250 gsm subjected to alkaline treatment for 4 h in a composite that has undergone 45 min of cryogenic treatment presented an improvement of 64% in impact strength, ca. 21% in flexural strength, ca. 158% in tensile strength and ca. 28% in hardness.

  • 10.
    Gangwani, Prashant
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements. Laboratory for Tribology and Interface Nanotechnology, University of Ljubljana, Ljubljana, 1000, Slovenia.
    Kalin, Mitjan
    Laboratory for Tribology and Interface Nanotechnology, University of Ljubljana, Ljubljana, 1000, Slovenia.
    Emami, Nazanin
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Does a Compatibilizer Enhance the Properties of Carbon Fiber-Reinforced Composites?2023In: Polymers, E-ISSN 2073-4360, Vol. 15, no 23, article id 4608Article in journal (Refereed)
    Abstract [en]

    We have evaluated the effectiveness of compatibilizers in blends and composites produced using a solvent manufacturing process. The compatibilizers were two different types of polyethylene (linear low-density and high-density) grafted with maleic anhydride (MAH) and a highly functionalized, epoxy-based compatibilizer with the tradename Joncryl. The selected material combinations were an ultra-high-molecular-weight polyethylene (UHMWPE) with MAH-based materials as compatibilizers and a polyphenylene sulfide plus polytetrafluoroethylene (PPS-PTFE) polymer blend with an epoxy-based compatibilizer. The findings revealed that while the compatibilizers consistently enhanced the properties, such as the impact strength and hardness of PPS-based compositions, their utility is constrained to less complex compositions, such as fibrous-reinforced PPS or PPS-PTFE polymer blends. For fibrous-reinforced PPS-PTFE composites, the improvement in performance does not justify the presence of compatibilizers. In contrast, for UHMWPE compositions, compatibilizers demonstrated negligible or even detrimental effects, particularly in reinforced UHMWPE. Overall, the epoxy-based compatibilizer Joncryl stands out as the only effective option for enhancing mechanical performance. Thermal and chemical characterization indicated that the compatibilizers function as chain extenders and enhance the fiber–matrix interface in PPS-based compositions, while they remain inactive in UHMWPE-based compositions. Ultimately, the incompatibility of the compatibilizers with certain aspects of the manufacturing method and the inconsistent integration with the polymer are the main reasons for their ineffectiveness in UHMWPE compositions.

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  • 11.
    Hafeez, Abdul
    et al.
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Akhter, Zareen
    Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
    Gallagher, John F.
    School of Chemical Sciences, Dublin City University, Glasnevin, Dublin, Ireland.
    Khan, Nawazish Ali
    Materials Science Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad, Pakistan.
    Gul, Asghari
    Department of Chemistry, COMSATS University, Islamabad, Pakistan.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Synthesis, Crystal Structures, and Spectroscopic Characterization of Bis-aldehyde Monomers and Their Electrically Conductive Pristine Polyazomethines2019In: Polymers, E-ISSN 2073-4360, Vol. 11, no 9, article id 1498Article in journal (Refereed)
    Abstract [en]

    Bis-aldehyde monomers 4-(4′-formyl-phenoxy)benzaldehyde (3a), 3-methoxy-4-(4′-formyl-phenoxy)benzaldehyde (3b), and 3-ethoxy-4-(4′-formyl-phenoxy)benzaldehyde (3c) were synthesized by etherification of 4-fluorobenzaldehyde (1) with 4-hydroxybenzaldehyde (2a), 3-methoxy-4-hydroxybenzaldehyde (2b), and 3-ethoxy-4-hydroxybenzaldehyde (2c), respectively. Each monomer was polymerized with p-phenylenediamine and 4,4′-diaminodiphenyl ether to yield six poly(azomethine)s. Single crystal X-ray diffraction structures of 3b and 3c were determined. The structural characterization of the monomers and poly(azomethine)s was performed by FT-IR and NMR spectroscopic techniques and elemental analysis. Physicochemical properties of polymers were investigated by powder X-ray diffraction, thermogravimetric analysis (TGA), viscometry, UV–vis, spectroscopy and photoluminescence. These polymers were subjected to electrical conductivity measurements by the four-probe method, and their conductivities were found to be in the range 4.0 × 10−5 to 6.4 × 10−5 Scm−1, which was significantly higher than the values reported so far.

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  • 12.
    Hassan, Enas A.
    et al.
    Cellulose and Paper Department & Centre of Excellence for Advanced Sciences, National Research Centre.
    Hassan, Mohammad L.
    Cellulose and Paper Department & Centre of Excellence for Advanced Sciences, National Research Centre.
    Abou-zeid, Ragab Esmail
    Cellulose and Paper Department & Centre of Excellence for Advanced Sciences, National Research Centre.
    Berglund, Linn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Use of bacterial cellulose and crosslinked cellulose nanofibers membranes for removal of oil from oil-in-water emulsions2017In: Polymers, E-ISSN 2073-4360, Vol. 9, no 9, article id 388Article in journal (Refereed)
    Abstract [en]

    Never-dried bacterial cellulose (BC) and crosslinked cellulose nanofibers (CNF) were used for the removal of oil from stabilized and non-stabilized oil-in-water emulsions with droplet sizes less than 1 µm. The CNF membranes were exchanged with isopropyl alcohol before drying. The microscopic structure of the prepared membranes was evaluated using scanning electron microscopy (SEM); the water flux and the rejection of oil were evaluated using a dead-end filtration cell. BC harvested after different incubation time periods (2 to 10 days) did not show a change in the width of the nanofibers, but only the thickness of the membranes was increased. Pure water flux was not affected as a result of increasing thicknesses of BC membranes harvested after 4–10 days while BC harvested after two days had significantly higher water flux than the others. BC showed a higher flux and efficiency in removing oil from oil emulsions than CNF membranes. Removal of oil by the different membranes from the non-stabilized oil emulsion was more efficient than from the stabilized one.

  • 13.
    Hassan, Mohammad L.
    et al.
    Cellulose and Paper Department & Centre of Excellence for Advanced Sciences, National Research Centre.
    Abou-zeid, Ragab Esmail
    Cellulose and Paper Department & Centre of Excellence for Advanced Sciences, National Research Centre.
    Hassan, Enas A.
    Cellulose and Paper Department & Centre of Excellence for Advanced Sciences, National Research Centre.
    Berglund, Linn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Aitomäki, Yvonne
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Membranes based on cellulose nanofibers and activated carbon for removal of Escherichia coli bacteria from water2017In: Polymers, E-ISSN 2073-4360, Vol. 9, no 8, article id 335Article in journal (Refereed)
    Abstract [en]

    Cellulosic nanomaterials are potential candidates in different areas, especially in water treatment. In the current work, palm fruit stalks cellulose nanofibers (CNF), TEMPO-oxidized CNF (OCNF), and activated carbon (AC) were used to make thin film membranes for removal of E. coli bacteria from water. Two types of layered membranes were produced: a single layer setup of crosslinked CNF and a two-layer setup of AC/OCNF (bottom) and crosslinked CNF (up) on hardened filter paper. The prepared membranes were evaluated regarding their microstructure and layers thickness using scanning electron microscopy (SEM). Water flux and rejection of E. coli bacteria was tested using dead end stirred cells at 1 MPa pressure. Thickness of the cosslinked CNF layer in both types of membranes was about 0.75 micron. The results showed that exchanging water by isopropyl alcohol before drying increased porosity of membranes, and thus resulted in increasing pure water flux and flux of bacteria suspension. The two-layer AC/OCNF/CNF membrane had much higher water flux than the single layer CNF due to higher porosity seen on the surface of the former. Both types of membranes showed high capability of removing E. coli bacteria (rejection ~96–99%) with slightly higher efficiency for the AC/OCNF/CNF membrane than CNF membrane. AC/OCNF/CNF membrane also showed resistance against growth of E. coli and S. aureus bacteria on the upper CNF surface while the single layer CNF membrane did not show resistance against growth of the aforementioned bacteria

  • 14.
    Hassan, Mohammad
    et al.
    Cellulose and Paper Department & Centre of Excellence for Advanced Sciences, National Research Centre, Dokki, Giza, Egypt. Egypt Nanotechnology Centre, Cairo University, 6th October City, Egypt.
    Zeid, Ragab E. Abou
    Cellulose and Paper Department & Centre of Excellence for Advanced Sciences, National Research Centre, Dokki, Giza, Egypt.
    Abou-Elseoud, Wafaa S.
    Cellulose and Paper Department & Centre of Excellence for Advanced Sciences, National Research Centre, Dokki, Giza, Egypt.
    Hassan, Enas
    Cellulose and Paper Department & Centre of Excellence for Advanced Sciences, National Research Centre, Dokki, Giza, Egypt.
    Berglund, Linn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada.
    Effect of Unbleached Rice Straw Cellulose Nanofibers on the Properties of Polysulfone Membranes2019In: Polymers, E-ISSN 2073-4360, Vol. 11, no 6, article id 938Article in journal (Refereed)
    Abstract [en]

    In addition to their lower cost and more environmentally friendly nature, cellulose nanofibers isolated from unbleached pulps offer different surface properties and functionality than those isolated from bleached pulps. At the same time, nanofibers isolated from unbleached pulps keep interesting properties such as hydrophilicity and mechanical strength, close to those isolated from bleached pulps. In the current work, rice straw nanofibers (RSNF) isolated from unbleached neutral sulfite pulp (lignin content 14%) were used with polysulfone (PSF) polymer to make membrane via phase inversion. The effect of RSNF on microstructure, porosity, hydrophilicity, mechanical properties, water flux, and fouling of PSF membranes was studied. In addition, the prepared membranes were tested to remove lime nanoparticles, an example of medium-size nanoparticles. The results showed that using RSNF at loadings from 0.5 to 2 wt.% can significantly increase hydrophilicity, porosity, water flux, and antifouling properties of PSF. RSNF also brought about an increase in rejection of lime nanoparticles (up to 98% rejection) from their aqueous suspension, and at the same time, with increasing flux across the membranes. Tensile strength of the membranes improved by ~29% with addition of RSNF and the maximum improvement was obtained on using 0.5% of RSNF, while Young’s modulus improved by ~40% at the same RSNF loading. As compared to previous published results on using cellulose nanofibers isolated from bleached pulps, the obtained results in the current work showed potential application of nanofibers isolated from unbleached pulps for improving important properties of PSF membranes, such as hydrophilicity, water flux, rejection, and antifouling properties

  • 15.
    Herrera Vargas, Natalia
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Singh, Anshu Anjali
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Salaberria, Asier M.
    Biorefinery Processes Research Group, Department of Chemical and Environmental Engineering, Faculty of Engineering, Guipúzcoa, University of the Basque Country.
    Labidi, Jalel
    Biorefinery Processes Research Group, Department of Chemical and Environmental Engineering, Faculty of Engineering, Guipúzcoa, University of the Basque Country.
    Mathew, Aji P.
    Division of Materials and Environmental Chemistry, Stockholm University.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Fibre and Particle Engineering, University of Oulu.
    Triethyl Citrate (TEC) as a Dispersing Aid in Polylactic Acid/Chitin Nanocomposites Prepared via Liquid-Assisted Extrusion2017In: Polymers, E-ISSN 2073-4360, Vol. 9, no 9, article id 406Article in journal (Refereed)
    Abstract [en]

    The production of fully bio-based and biodegradable nanocomposites has gained attention during recent years due to environmental reasons; however, the production of these nanocomposites on the large-scale is challenging. Polylactic acid/chitin nanocrystal (PLA/ChNC) nanocomposites with triethyl citrate (TEC) at varied concentrations (2.5, 5.0, and 7.5 wt %) were prepared using liquid-assisted extrusion. The goal was to find the minimum amount of the TEC plasticizer needed to enhance the ChNC dispersion. The microscopy study showed that the dispersion and distribution of the ChNC into PLA improved with the increasing TEC content. Hence, the nanocomposite with the highest plasticizer content (7.5 wt %) showed the highest optical transparency and improved thermal and mechanical properties compared with its counterpart without the ChNC. Gel permeation chromatography confirmed that the water and ethanol used during the extrusion did not degrade PLA. Further, Fourier transform infrared spectroscopy showed improved interaction between PLA and ChNC through hydrogen bonding when TEC was added. All results confirmed that the plasticizer plays an important role as a dispersing aid in the processing of PLA/ChNC nanocomposites.

  • 16.
    Javad Razavi, Seyed Mohammad
    et al.
    Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), Richard Birkelands vei 2b, 7491 Trondheim, Norway.
    Esmaeely Neisiany, Rasoul
    Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran.
    Razavi, Moe
    Department of Chemical Engineering, Isfahan University of Technology, Isfahan 8415683111, Iran.
    Fakhar, Afsaneh
    Department of Chemical Engineering, Isfahan University of Technology, Isfahan 8415683111, Iran.
    Shanmugam, Vigneshwaran
    Department of Mechanical Engineering, Saveetha Institute of Medical and Technical Sciences, Saveetha School of Engineering, Chennai 602105, India.
    Alagumalai, Vasudevan
    Department of Mechanical Engineering, Saveetha Institute of Medical and Technical Sciences, Saveetha School of Engineering, Chennai 602105, India.
    Försth, Michael
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Efficient Improvement in Fracture Toughness of Laminated Composite by Interleaving Functionalized Nanofibers2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 15, article id 2509Article in journal (Refereed)
    Abstract [en]

    Functionalized polyacrylonitrile (PAN) nanofibers were used in the present investigation to enhance the fracture behavior of carbon epoxy composite in order to prevent delamination if any crack propagates in the resin rich area. The main intent of this investigation was to analyze the efficiency of PAN nanofiber as a reinforcing agent for the carbon fiber-based epoxy structural composite. The composites were fabricated with stacked unidirectional carbon fibers and the PAN powder was functionalized with glycidyl methacrylate (GMA) and then used as reinforcement. The fabricated composites’ fracture behavior was analyzed through a double cantilever beam test and the energy release rate of the composites was investigated. The neat PAN and functionalized PAN-reinforced samples had an 18% and a 50% increase in fracture energy, respectively, compared to the control composite. In addition, the samples reinforced with functionalized PAN nanofibers had 27% higher interlaminar strength compared to neat PAN-reinforced composite, implying more efficient stress transformation as well as stress distribution from the matrix phase (resin-rich area) to the reinforcement phase (carbon/phase) of the composites. The enhancement of fracture toughness provides an opportunity to alleviate the prevalent issues in laminated composites for structural operations and facilitate their adoption in industries for critical applications.

  • 17.
    Jiang, Lin
    et al.
    School of Mechanical Engineering, Nanjing University of Science and Technology, China.
    Yang, Xin-Rui
    School of Mechanical Engineering, Nanjing University of Science and Technology, China.
    Gao, Xu
    School of Mechanical Engineering, Nanjing University of Science and Technology, China.
    Xu, Qiang
    School of Mechanical Engineering, Nanjing University of Science and Technology, China.
    Das, Oisik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Sun, Jin-Hua
    State key laboratory of Fire Science, University of Science and Technology of China, China.
    Kuzman, Manja Kitek
    Department of Wood Science and Technology, Biotechnical Faculty, University of Ljubljana, Slovenia.
    Pyrolytic Kinetics of Polystyrene Particle in Nitrogen Atmosphere: Particle Size Effects and Application of Distributed Activation Energy Method2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 2, article id 421Article in journal (Refereed)
    Abstract [en]

    This work was motivated by a study of particle size effects on pyrolysis kinetics and models of polystyrene particle. Micro-size polystyrene particles with four different diameters, 5, 10, 15, and 50 µm, were selected as experimental materials. Activation energies were obtained by isoconversional methods, and pyrolysis model of each particle size and heating rate was examined through different reaction models by the Coats–Redfern method. To identify the controlling model, the Avrami–Eroféev model was identified as the controlling pyrolysis model for polystyrene pyrolysis. Accommodation function effect was employed to modify the Avrami–Eroféev model. The model was then modified to f(α) = nα0.39n − 1.15(1 − α)[−ln(1 − α)]1 − 1/n, by which the polystyrene pyrolysis with different particle sizes can be well explained. It was found that the reaction model cannot be influenced by particle geometric dimension. The reaction rate can be changed because the specific surface area will decrease with particle diameter. To separate each step reaction and identify their distributions to kinetics, distributed activation energy method was introduced to calculate the weight factor and kinetic triplets. Results showed that particle size has big impacts on both first and second step reactions. Smaller size particle can accelerate the process of pyrolysis reaction. Finally, sensitivity analysis was brought to check the sensitivity and weight of each parameter in the model.

  • 18.
    Khadem, Elham
    et al.
    Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
    Kharaziha, Mahshid
    Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
    Bakhsheshi-Rad, Hamid Reza
    Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Berto, Filippo
    Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
    Cutting-Edge Progress in Stimuli-Responsive Bioadhesives: From Synthesis to Clinical Applications2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 9, article id 1709Article, review/survey (Refereed)
    Abstract [en]

    With the advent of “intelligent” materials, the design of smart bioadhesives responding to chemical, physical, or biological stimuli has been widely developed in biomedical applications to minimize the risk of wounds reopening, chronic pain, and inflammation. Intelligent bioadhesives are free-flowing liquid solutions passing through a phase shift in the physiological environment due to stimuli such as light, temperature, pH, and electric field. They possess great merits, such as ease to access and the ability to sustained release as well as the spatial transfer of a biomolecule with reduced side effects. Tissue engineering, wound healing, drug delivery, regenerative biomedicine, cancer therapy, and other fields have benefited from smart bioadhesives. Recently, many disciplinary attempts have been performed to promote the functionality of smart bioadhesives and discover innovative compositions. However, according to our knowledge, the development of multifunctional bioadhesives for various biomedical applications has not been adequately explored. This review aims to summarize the most recent cutting-edge strategies (years 2015–2021) developed for stimuli-sensitive bioadhesives responding to external stimuli. We first focus on five primary categories of stimuli-responsive bioadhesive systems (pH, thermal, light, electric field, and biomolecules), their properties, and limitations. Following the introduction of principal criteria for smart bioadhesives, their performances are discussed, and certain smart polymeric materials employed in their creation in 2015 are studied. Finally, advantages, disadvantages, and future directions regarding smart bioadhesives for biomedical applications are surveyed.

  • 19.
    Khosravi, Fatemeh
    et al.
    Department of Chemical Engineering, Isfahan University of Technology, Isfahan 8415683111, Iran.
    Nouri Khorasani, Saied
    Department of Chemical Engineering, Isfahan University of Technology, Isfahan 8415683111, Iran.
    Khalili, Shahla
    Department of Chemical Engineering, Isfahan University of Technology, Isfahan 8415683111, Iran.
    Esmaeely Neisiany, Rasoul
    Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran.
    Rezvani Ghomi, Erfan
    Department of Mechanical Engineering, Center for Nanofibers and Nanotechnology, National University of Singapore, Singapore 119260, Singapore.
    Ejeian, Fatemeh
    Department of Cellular Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan 8159358686, Iran.
    Das, Oisik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Nasr-Esfahani, Mohammad Hossein
    Department of Cellular Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan 8159358686, Iran.
    Development of a Highly Proliferated Bilayer Coating on 316L Stainless Steel Implants2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 5, article id 1022Article in journal (Refereed)
    Abstract [en]

    In this research, a bilayer coating has been applied on the surface of 316 L stainless steel (316LSS) to provide highly proliferated metallic implants for bone regeneration. The first layer was prepared using electrophoretic deposition of graphene oxide (GO), while the top layer was coated utilizing electrospinning of poly (ε-caprolactone) (PCL)/gelatin (Ge)/forsterite solutions. The morphology, porosity, wettability, biodegradability, bioactivity, cell attachment and cell viability of the prepared coatings were evaluated. The Field Emission Scanning Electron Microscopy (FESEM) results revealed the formation of uniform, continuous, and bead-free nanofibers. The Energy Dispersive X-ray (EDS) results confirmed well-distributed forsterite nanoparticles in the structure of the top coating. The porosity of the electrospun nanofibers was found to be above 70%. The water contact angle measurements indicated an improvement in the wettability of the coating by increasing the amount of nanoparticles. Furthermore, the electrospun nanofibers containing 1 and 3 wt.% of forsterite nanoparticles showed significant bioactivity after soaking in the simulated body fluid (SBF) solution for 21 days. In addition, to investigate the in vitro analysis, the MG-63 cells were cultured on the PCL/Ge/forsterite and GO-PCL/Ge/forsterite coatings. The results confirmed an excellent cell adhesion along with considerable cell growth and proliferation. It should be also noted that the existence of the forsterite nanoparticles and the GO layer substantially enhanced the cell proliferation of the coatings.

  • 20.
    Kohli, Isha
    et al.
    Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia.
    Srivatsa, Srikanth Chakravartula
    Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Devasahayam, Sheila
    WASM—Minerals, Energy and Chemical Engineering, Curtin University, Perth, WA 6845, Australia.
    Singh Raman, R. K.
    Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia; Department of Mechanical & Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia.
    Bhattacharya, Sankar
    Department of Chemical and Biological Engineering, Monash University, Clayton, VIC 3800, Australia.
    Pyrolysis of Automotive Shredder Residue (ASR): Thermogravimetry, In-Situ Synchrotron IR and Gas-Phase IR of Polymeric Components2023In: Polymers, E-ISSN 2073-4360, Vol. 15, no 17, article id 3650Article in journal (Refereed)
    Abstract [en]

    This article reports the characterisation of pyrolysis of automotive shredder residue using in situ synchrotron IR, gas-phase IR, and thermal analyses to explore if the automotive shredder residue can be converted into value-added products. When heating to ~600 °C at different heating rates, thermal analyses suggested one- to two-stage pyrolysis. Transformations in the first stage, at lower temperatures, were attributed to the degradation of carbonyl, hydroxyl, or carboxyl functional stabilisers (aldehyde and ether impurities, additives, and stabilisers in the ASR). The second stage transformations, at higher temperatures, were attributed to the thermal degradation of the polymer char. Simultaneous thermal analyses and gas-phase IR spectroscopy confirmed the evolution of the gases (alkanes (CH4), CO2, and moisture). The synchrotron IR data have demonstrated that a high heating rate (such as 150 °C/min) results in an incomplete conversion of ASRs unless sufficient time is provided. The thermogravimetry data fit the linearised multistage kinetic model at different heating rates. The activation energy of reactions varied between 24.98 and 124.94 kJ/mol, indicating a surface-controlled reaction exhibiting high activation energy during the initial stages and a diffusion and mass transfer control showing lower activation energy at the final stages. The corresponding frequency factors were in the range of 3.34 × 1013–5.68 × 101 mg−1/min for different pyrolysis stages. The evolution of the functional groups decreased with an increase in the heating rate.

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  • 21.
    Kumar, Vishnu Vijay
    et al.
    Centre for Nanofibers and Nanotechnology, Department of Mechanical Engineering, National University of Singapore, Singapore. Department of Ocean Engineering, Indian Institute of Technology, Madras, India.
    Balaganesan, G
    Department of Mechanical Engineering, Indian Institute of Technology, Jammu, India.
    Lee, Jeremy Kong Yoong
    Centre for Nanofibers and Nanotechnology, Department of Mechanical Engineering, National University of Singapore, Singapore.
    Neisiany, Rasoul Esmaeely
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Surendran, S
    Department of Ocean Engineering, Indian Institute of Technology, Madras, India.
    Ramakrishna, Seeram
    Centre for Nanofibers and Nanotechnology, Department of Mechanical Engineering, National University of Singapore, Singapore.
    A Review of Recent Advances in Nanoengineered Polymer Composites2019In: Polymers, E-ISSN 2073-4360, Vol. 11, no 4, article id 644Article in journal (Refereed)
    Abstract [en]

    This review paper initially summarizes the latest developments in impact testing on polymer matrix composites collating the various analytical, numerical, and experimental studies performed since the year 2000. Subsequently, the scientific literature investigating nanofiller reinforced polymer composite matrices as well as self-healing polymer matrix composites by incorporating core-shell nanofibers is reviewed in-depth to provide a perspective on some novel advances in nanotechnology that have led to composite developments. Through this review, researchers can gain a representative idea of the state of the art in nanotechnology for polymer matrix composite engineering, providing a platform for further study of this increasingly industrially significant material, and to address the challenges in developing the next generation of advanced, high-performance materials.

  • 22.
    Lin, Chia-Feng
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Karlsson, Olov
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Kim, Injeong
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Myronycheva, Olena
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Mensah, Rhoda Afriyie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Försth, Michael
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Mantanis, George I.
    Laboratory of Wood Science and Technology, Faculty of Forestry, Wood Sciences and Design, University of Thessaly, GR-431 00 Karditsa, Greece.
    Jones, Dennis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering. Department of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Praha 6-Suchdol, CZ-16521 Prague, Czech Republic.
    Sandberg, Dick
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering. Department of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Praha 6-Suchdol, CZ-16521 Prague, Czech Republic.
    Fire Retardancy and Leaching Resistance of Furfurylated Pine Wood (Pinus sylvestris L.) Treated with Guanyl-Urea Phosphate2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 9, article id 1829Article in journal (Refereed)
    Abstract [en]

    Guanyl-urea phosphate (GUP) was introduced into furfurylated wood in order to improve fire retardancy. Modified wood was produced via vacuum-pressure impregnation of the GUP–furfuryl alcohol (FA) aqueous solution, which was then polymerized at elevated temperature. The water leaching resistance of the treated wood was tested according to European standard EN 84, while the leached water was analyzed using ultra-performance liquid chromatography (UPLC) and inductively coupled plasma–sector field mass spectrometry (ICP-SFMS). This new type of furfurylated wood was further characterized in the laboratory by evaluating its morphology and elemental composition using optical microscopy and electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM-EDX). The chemical functionality was detected using infrared spectroscopy (FTIR), and the fire resistance was tested using cone calorimetry. The dimensional stability was evaluated in wet–dry soaking cycle tests, along with the mechanical properties, such as the Brinell hardness and bending strength. The fire retardancy of the modified furfurylated wood indicated that the flammability of wood can be depressed to some extent by introducing GUP. This was reflected in an observed reduction in heat release rate (HRR2) from 454.8 to 264.9 kW/m2, without a reduction in the material properties. In addition, this leaching-resistant furfurylated wood exhibited higher fire retardancy compared to conventional furfurylated wood. A potential method for producing fire-retardant treated furfurylated wood stable to water exposure has been suggested.

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  • 23.
    Masood, Asad
    et al.
    Institute of Microengineering and Nanoelectronics, University Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia.
    Ahmed, Naeem
    Institute of Microengineering and Nanoelectronics, University Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia.
    Razip Wee, M. F. Mohd
    Institute of Microengineering and Nanoelectronics, University Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia.
    Patra, Anuttam
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Mahmoudi, Ebrahim
    Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia.
    Siow, Kim S.
    Institute of Microengineering and Nanoelectronics, University Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia.
    Atmospheric Pressure Plasma Polymerisation of D-Limonene and Its Antimicrobial Activity2023In: Polymers, E-ISSN 2073-4360, Vol. 15, no 2, article id 307Article in journal (Refereed)
    Abstract [en]

    Antibacterial coating is necessary to prevent biofilm-forming bacteria from colonising medical tools causing infection and sepsis in patients. The recent coating strategies such as immobilisation of antimicrobial materials and low-pressure plasma polymerisation may require multiple processing steps involving a high-vacuum system and time-consuming process. Some of those have limited efficacy and durability. Here, we report a rapid and one-step atmospheric pressure plasma polymerisation (APPP) of D-limonene to produce nano-thin films with hydrophobic-like properties for antibacterial applications. The influence of plasma polymerisation time on the thickness, surface characteristic, and chemical composition of the plasma-polymerised films was systematically investigated. Results showed that the nano-thin films deposited at 1 min on glass substrate are optically transparent and homogenous, with a thickness of 44.3 ± 4.8 nm, a smooth surface with an average roughness of 0.23 ± 0.02 nm. For its antimicrobial activity, the biofilm assay evaluation revealed a significant 94% decrease in the number of Escherichia coli (E. coli) compared to the control sample. More importantly, the resultant nano-thin films exhibited a potent bactericidal effect that can distort and rupture the membrane of the treated bacteria. These findings provide important insights into the development of bacteria-resistant and biocompatible coatings on the arbitrary substrate in a straightforward and cost-effective route at atmospheric pressure.

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  • 24.
    Mensah, Rhoda Afriyie
    et al.
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Xiao, Jie
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Das, Oisik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Jiang, Lin
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Xu, Qiang
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Alhassan, Mohammed Okoe
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Application of Adaptive Neuro-Fuzzy Inference System in Flammability Parameter Prediction2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 1, article id 122Article in journal (Refereed)
    Abstract [en]

    The fire behavior of materials is usually modeled on the basis of fire physics and material composition. However, significant strides have been made recently in applying soft computing methods such as artificial intelligence in flammability studies. In this paper, multiple linear regression (MLR) was employed to test the degree of non-linearities in flammability parameter modeling by assessing the linear relationship between sample mass, heating rate, heat release capacity (HRC) and total heat release (THR). Adaptive neuro-fuzzy inference system (ANFIS) was then adopted to predict the HRC and THR of the extruded polystyrene measured from microscale combustion calorimetry experiments. The ANFIS models presented excellent predictions, showing very low mean training and testing errors as well as reasonable agreements between experimental and predicted datasets. Hence, it can be inferred that ANFIS can handle the non-linearities in flammability modeling, making it apt as a modeling technique for accurate and effective flammability assessments.

  • 25.
    Mushtaq, Irrum
    et al.
    Department of Biological Sciences, National University of Medical Sciences, The Mall Road, Rawalpindi 46000, Pakistan; Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan.
    Jabeen, Erum
    Department of Chemistry, Faculty of Science, Allama Iqbal Open University, Islamabad 44310, Pakistan.
    Akhter, Zareen
    Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan.
    Javed, Fatima
    Department of Chemistry, Shaheed Benazir Bhutto Women University, Peshawar 25000, Pakistan.
    Hassan, Azfar
    Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada.
    Khan, Muhammad Saif Ullah
    Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan.
    Ullah, Faheem
    Department of Biological Sciences, National University of Medical Sciences, The Mall Road, Rawalpindi 46000, Pakistan; School of Materials and Mineral Resources Engineering, Engineering Campus, University Sains Malaysia, Nibong Tebal 14300, Malaysia.
    Shah, Faiz Ullah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Ferrocene-Based Terpolyamides and Their PDMS-Containing Block Copolymers: Synthesis and Physical Properties2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 23, article id 5087Article in journal (Refereed)
    Abstract [en]

    Aromatic polyamides are well-known as high-performance materials due to their outstanding properties making them useful in a wide range of applications. However, their limited solubility in common organic solvents restricts their processability and becomes a hurdle in their applicability. This study is focused on the synthesis of processable ferrocene-based terpolyamides and their polydimethylsiloxane (PDMS)-containing block copolymers, using low-temperature solution polycondensation methodology. All the synthesized materials were structurally characterized using FTIR and 1H NMR spectroscopic techniques. The ferrocene-based terpolymers and block copolymers were soluble in common organic solvents, while the organic analogs were found only soluble in sulfuric acid. WXRD analysis showed the amorphous nature of the materials, while the SEM analysis exposed the modified surface of the ferrocene-based block copolymers. The structure–property relationship of the materials was further elucidated by their water absorption and thermal behavior. These materials showed low to no water absorption along with their high limiting oxygen index (LOI) values depicting their good flame-retardant behavior. DFT studies also supported the role of various monomers in the polycondensation reaction where the electron pair donation from HOMO of diamine monomer to the LUMO of acyl chloride was predicted, along with the calculation of various other parameters of the representative terpolymers and block copolymers.

  • 26.
    Oliver-Ortega, Helena
    et al.
    Group LEPAMAP, Department of Chemical Engineering, University of Girona, EPS. Ed. PI. C/ Maria Aurelia Capmany 61, 17003 Girona, Spain.
    Geng, Shiyu
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Espinach, Francesc Xavier
    Design, Development and Product Innovation, Department Organization, Business Management and Product Design, University of Girona, C/ Maria Aurelia Capmany 61, 17003 Girona, Spain.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Mechanical & Industrial Engineering (MIE), University of Toronto, Toronto, ON M5S 3G8, Canada.
    Vilaseca, Fabiola
    Engineering Materials, Industrial and Materials Science, Chalmers University of Technology, SE 41296 Göteborg, Sweden. BIMATEC, Department of Chemical Engineering, University of Girona, EPS. Ed. PI. C/ Maria Aurelia Capmany 61, 17003 Girona, Spain.
    Bacterial Cellulose Network from Kombucha Fermentation Impregnated with Emulsion-Polymerized Poly(methyl methacrylate) to Form Nanocomposite2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 4, article id 664Article in journal (Refereed)
    Abstract [en]

    The use of bio-based residues is one of the key indicators towards sustainable development goals. In this work, bacterial cellulose, a residue from the fermentation of kombucha tea, was tested as a reinforcing nanofiber network in an emulsion-polymerized poly(methyl methacrylate) (PMMA) matrix. The use of the nanofiber network is facilitating the formation of nanocomposites with well-dispersed nanofibers without using organic solvents or expensive methodologies. Moreover, the bacterial cellulose network structure can serve as a template for the emulsion polymerization of PMMA. The morphology, size, crystallinity, water uptake, and mechanical properties of the kombucha bacterial cellulose (KBC) network were studied. The results showed that KBC nanofibril diameters were ranging between 20–40 nm and the KBC was highly crystalline, >90%. The 3D network was lightweight and porous material, having a density of only 0.014 g/cm3. Furthermore, the compressed KBC network had very good mechanical properties, the E-modulus was 8 GPa, and the tensile strength was 172 MPa. The prepared nanocomposites with a KBC concentration of 8 wt.% were translucent with uniform structure confirmed with scanning electron microscopy study, and furthermore, the KBC network was homogeneously impregnated with the PMMA matrix. The mechanical testing of the nanocomposite showed high stiffness compared to the neat PMMA. A simple simulation of the tensile strength was used to understand the limited strain and strength given by the bacterial cellulose network. The excellent properties of the final material demonstrate the capability of a residue of kombucha fermentation as an excellent nanofiber template for use in polymer nanocomposites.

  • 27.
    Patel, Mitul Kumar
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Zaccone, Marta
    Proplast, Via Roberto di Ferro 86, 15122 Alessandria, Italy.
    De Brauwer, Laurens
    Bio Base Europe Pilot Plant (BBEPP), Rodenhuizekaai 1, Gent, 9042, Belgium.
    Nair, Rakesh
    Bio Base Europe Pilot Plant (BBEPP), Rodenhuizekaai 1, Gent, 9042, Belgium.
    Monti, Marco
    Proplast, Via Roberto di Ferro 86, 15122 Alessandria, Italy.
    Martinez-Nogues, Vanesa
    Tecnopackaging, Polígono Industrial Empresarium, Calle Romero 12, 50720 Zaragoza, Spain.
    Frache, Alberto
    Department of Applied Science and Technology and Local INSTM Unit, Politecnico di Torino, Viale Teresa Michel 5, Alessandria, 15121, Italy.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Mechanical & Industrial Engineering (MIE), University of Toronto, Toronto, ON M5S 3G8, Canada; Wallenberg Wood Science Center (WWSC), Luleå University of Technology, SE-97187 Luleå, Sweden.
    Improvement of Poly(lactic acid)-Poly(hydroxy butyrate) Blend Properties for Use in Food Packaging: Processing, Structure Relationships2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 23, article id 5104Article in journal (Refereed)
    Abstract [en]

    Poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB)-based nanocomposite films were prepared with bio-based additives (CNCs and ChNCs) and oligomer lactic acid (OLA) compatibilizer using extrusion and then blown to films at pilot scale. The aim was to identify suitable material formulations and nanocomposite production processes for film production at a larger scale targeting food packaging applications. The film-blowing process for both the PLA-PHB blend and CNC-nanocomposite was unstable and led to non-homogeneous films with wrinkles and creases, while the blowing of the ChNC-nanocomposite was stable and resulted in a smooth and homogeneous film. The optical microscopy of the blown nanocomposite films indicated well-dispersed chitin nanocrystals while the cellulose crystals were agglomerated to micrometer-size particles. The addition of the ChNCs also resulted in the improved mechanical performance of the PLA-PHB blend due to well-dispersed crystals in the nanoscale as well as the interaction between biopolymers and the chitin nanocrystals. The strength increased from 27 MPa to 37 MPa compared to the PLA-PHB blend and showed almost 36 times higher elongation at break resulting in 10 times tougher material. Finally, the nanocomposite film with ChNCs showed improved oxygen barrier performance as well as faster degradation, indicating its potential exploitation for packaging applications.

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  • 28.
    Qiao, Yuanhua
    et al.
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Zhao, Shu-Na
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Sun, Tong-Sheng
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Jiang, Lin
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Pyrolysis Kinetic Study and Reaction Mechanism of Epoxy Glass Fiber Reinforced Plastic by Thermogravimetric Analyzer (TG) and TG–FTIR (Fourier-Transform Infrared) Techniques2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 11, article id 2739Article in journal (Refereed)
    Abstract [en]

    TG–FTIR combined technology was used to study the degradation process and gas phase products of epoxy glass fiber reinforced plastic (glass fiber reinforced plastic) under the atmospheres of high purity nitrogen. The pyrolysis characteristics of epoxy glass fiber reinforced plastic were measured under different heating rates (5, 10, 15, 20 °C min−1) from 25 to 1000 °C. The thermogravimetric analyzer (TG) and differential thermogravimetric analyzer (DTG) curves show that the initial temperature, terminal temperature, and temperature of maximum weight loss rate in the pyrolysis reaction phase all move towards high temperature, as the heating rate increases. Epoxy glass fiber reinforced plastic has two stages of thermal weightlessness. The temperature range of the first stage of weight loss is 290–460 °C. The second stage is 460–1000 °C. The above two weight loss stages are caused by pyrolysis of the epoxy resin matrix, and the glass fiber will not decompose. The dynamic parameters of glass fiber reinforced plastic were obtained through the Kissinger-Akahira-Sunose (KAS), Flynn–Wall-Ozawa (FWO) and advanced Vyazovkin methods in model-free and the Coats–Redfern (CR) method in model fitting. FTIR spectrum result shows that the main components of the product gas are CO2, H2O, carbonyl components, and aromatic components during its pyrolysis.

  • 29.
    Renner, Juliana Sally
    et al.
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Mensah, Rhoda Afriyie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Jiang, Lin
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Xu, Qiang
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Berto, Filippo
    Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway.
    Fire behavior of wood-based composite materials2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 24, article id 4352Article, review/survey (Refereed)
    Abstract [en]

    Wood-based composites such as wood plastic composites (WPC) are emerging as a sustainable and excellent performance materials consisting of wood reinforced with polymer matrix with a variety of applications in construction industries. In this context, wood-based composite materials used in construction industries have witnessed a vigorous growth, leading to a great production activity. However, the main setbacks are their high flammability during fires. To address this issue, flame retardants are utilized to improve the performance of fire properties as well as the flame retardancy of WPC material. In this review, flame retardants employed during manufacturing process with their mechanical properties designed to achieve an enhanced flame retardancy were examined. The addition of flame retardants and manufacturing techniques applied were found to be an optimum condition to improve fire resistance and mechanical properties. The review focuses on the manufacturing techniques, applications, mechanical properties and flammability studies of wood fiber/flour polymer/plastics composites materials. Various flame retardant of WPCs and summary of future prospects were also highlighted.

  • 30.
    Rezvani Ghomi, Erfan
    et al.
    Center for Nanotechnology and Sustainability, Department of Mechanical Engineering, National University of Singapore, Singapore 117581, Singapore.
    Khosravi, Fatemeh
    Center for Nanotechnology and Sustainability, Department of Mechanical Engineering, National University of Singapore, Singapore 117581, Singapore.
    Saedi Ardahaei, Ali
    Department of Polymer Engineering, Faculty of Engineering, Golestan University, P.O. Box 491888369, Gorgan 1575949138, Iran.
    Dai, Yunqian
    School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China.
    Neisiany, Rasoul Esmaeely
    Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran.
    Foroughi, Firoozeh
    Department of Materials Science and Engineering, Faculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, Singapore.
    Wu, Min
    School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Ramakrishna, Seeram
    Center for Nanotechnology and Sustainability, Department of Mechanical Engineering, National University of Singapore, Singapore 117581, Singapore.
    The Life Cycle Assessment for Polylactic Acid (PLA) to Make It a Low-Carbon Material2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 11, article id 1854Article, review/survey (Refereed)
    Abstract [en]

    The massive plastic production worldwide leads to a global concern for the pollution made by the plastic wastes and the environmental issues associated with them. One of the best solutions is replacing the fossil-based plastics with bioplastics. Bioplastics such as polylactic acid (PLA) are biodegradable materials with less greenhouse gas (GHG) emissions. PLA is a biopolymer produced from natural resources with good mechanical and chemical properties, therefore, it is used widely in packaging, agriculture, and biomedical industries. PLA products mostly end up in landfills or composting. In this review paper, the existing life cycle assessments (LCA) for PLA were comprehensively reviewed and classified. According to the LCAs, the energy and materials used in the whole life cycle of PLA were reported. Finally, the GHG emissions of PLA in each stage of its life cycle, including feedstock acquisition and conversion, manufacturing of PLA products, the PLA applications, and the end of life (EoL) options, were described. The most energy-intensive stage in the life cycle of PLA is its conversion. By optimizing the conversion process of PLA, it is possible to make it a low-carbon material with less dependence on energy sources.

  • 31.
    Rosenstock Völtz, Luísa
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Di Guiseppe, Irangeli
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Geng, Shiyu
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    The Effect of Recycling on Wood-Fiber Thermoplastic Composites2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 8, article id 1750Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to investigate the effect of recycling on polypropylene (PP) and wood-fiber thermoplastic composites (WPCs) using a co-rotating twin-screw extruder. After nine extrusion passes microscopy studies confirmed that the fiber length decreased with the increased number of recycling passes but the increased processing time also resulted in excellent dispersion and interfacial adhesion of the wood fibers in the PP matrix. Thermal, rheological, and mechanical properties were studied. The repeated extrusion passes had minimal effect on thermal behavior and the viscosity decreased with an increased number of passes, indicating slight degradation. The recycling processes had an effect on the tensile strength of WPCs while the effect was minor on the PP. However, even after the nine recycling passes the strength of WPC was considerably better (37 MPa) compared to PP (28 MPa). The good degree of property retention after recycling makes this recycling strategy a viable alternative to discarding the materials. Thus, it has been demonstrated that, by following the most commonly used extrusion process, WPCs can be recycled several times and this methodology can be industrially adapted for the manufacturing of recycled products.

  • 32.
    Singh, Shikha
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Centre Català del Plàstic (CCP), Universitat Politècnica de Catalunya Barcelona Tech (EEBE-UPC), C/Colom 114, Terrassa 08222, Spain.
    Patel, Mitul
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Schwendemann, Daniel
    Luleå University of Technology, Department of Engineering Sciences and Mathematics. IWK Institut für Werkstofftechnik und Kunststoffverarbeitung, CH-8640 Rapperswil, Switzerland.
    Zaccone, Marta
    Proplast, Via Roberto di Ferro 86, 15122 Alessandria, Italy.
    Geng, Shiyu
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Maspoch, Maria Lluisa
    Centre Català del Plàstic (CCP), Universitat Politècnica de Catalunya Barcelona Tech (EEBE-UPC), C/Colom 114, Terrassa 08222, Spain.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Mechanical & Industrial Engineering, University of Toronto, Toronto, ON M5S 3BS, Canada.
    Effect of Chitin Nanocrystals on Crystallization and Properties of Poly(lactic acid)-Based Nanocomposites2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 3, article id 726Article in journal (Refereed)
    Abstract [en]

    The crystalline phase of poly(lactic acid) (PLA) has crucial eects on its own propertiesand nanocomposites. In this study, the isothermal crystallization of PLA, triethyl citrate-plasticizedPLA (PLA–TEC), and its nanocomposite with chitin nanocrystals (PLA–TEC–ChNC) at dierenttemperatures and times was investigated, and the resulting properties of the materials werecharacterized. Both PLA and PLA–TEC showed extremely low crystallinity at isothermal temperaturesof 135, 130, 125 ºC and times of 5 or 15 min. In contrast, the addition of 1 wt % of ChNCs significantlyimproved the crystallinity of PLA under the same conditions owing to the nucleation eect ofthe ChNCs. The samples were also crystallized at 110 ºC to reach their maximal crystallinity,and PLA–TEC–ChNC achieved 48% crystallinity within 5 min, while PLA and PLA–TEC required 40 min to reach a similar level. Moreover, X-ray diffraction analysis showed that the addition ofChNCs resulted in smaller crystallite sizes, which further influenced the barrier properties and hydrolytic degradation of the PLA. The nanocomposites had considerably lower barrier propertiesand underwent faster degradation compared to PLA–TEC110. These results confirm that the additionof ChNCs in PLA leads to promising properties for packaging applications.

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  • 33.
    Siqueira, Gilberto
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Bras, Julien
    International School of Paper, Print Media and Biomaterials (Pagora), Grenoble Institute of Technology.
    Dufresne, Alain
    International School of Paper, Print Media and Biomaterials (Pagora), Grenoble Institute of Technology.
    Cellulosic bionanocomposites: a review of preparation, properties and applications2010In: Polymers, E-ISSN 2073-4360, Vol. 2, no 4, p. 728-765Article in journal (Refereed)
    Abstract [en]

    Cellulose is the most abundant biomass material in nature. Extracted from natural fibers, its hierarchical and multi-level organization allows different kinds of nanoscaled cellulosic fillers-called cellulose nanocrystals or microfibrillated cellulose (MFC)-to be obtained. Recently, such cellulose nanoparticles have been the focus of an exponentially increasing number of works or reviews devoted to understanding such materials and their applications. Major studies over the last decades have shown that cellulose nanoparticles could be used as fillers to improve mechanical and barrier properties of biocomposites. Their use for industrial packaging is being investigated, with continuous studies to find innovative solutions for efficient and sustainable systems. Processing is more and more important and different systems are detailed in this paper depending on the polymer solubility, i.e., (i) hydrosoluble systems, (ii) non-hydrosoluble systems, and (iii) emulsion systems. This paper intends to give a clear overview of cellulose nanoparticles reinforced composites with more than 150 references by describing their preparation, characterization, properties and applications

  • 34.
    Xu, Qiang
    et al.
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210014, China.
    Jiang, Lin
    School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210014, China.
    Majlingova, Andrea
    Faculty of Wood Science and Technology, Technical University in Zvolen, 96053 Zvolen, Slovakia.
    Ulbrikova, Nikoleta
    Faculty of Wood Science and Technology, Technical University in Zvolen, 96053 Zvolen, Slovakia.
    Mensah, Rhoda Afriyie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Berto, Filippo
    Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway.
    Wood Dust Flammability Analysis by Microscale Combustion Calorimetry2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 1, article id 45Article in journal (Refereed)
    Abstract [en]

    To study the practicability of a micro combustion calorimeter to analyze the calorimetry kinetics of wood, a micro combustion calorimeter with 13 heating rates from 0.1 to 5.5 K/s was used to perform the analysis of 10 kinds of common hardwood and softwood samples. As a microscale combustion measurement method, MCC (microscale combustion calorimetry) can be used to judge the flammability of materials. However, there are two methods for measuring MCC: Method A and Method B. However, there is no uniform standard for the application of combustible MCC methods. In this study, the two MCC standard measurement Methods A and B were employed to check their practicability. With Method A, the maximum specific heat release rate, heat release temperature, and specific heat release of the samples were obtained at different heating rates, while for Method B, the maximum specific combustion rate, combustion temperature and net calorific values of the samples were obtained at different heating rates. The ignition capacity and heat release capacity were then derived and evaluated for all the common hardwood and softwood samples. The results obtained by the two methods have significant differences in the shape of the specific heat release rate curves and the amplitude of the characteristic parameters, which lead to the differences of the derived parameters. A comparison of the specific heat release and the net calorific heat of combustion with the gross caloric values and heating values obtained by bomb calorimetry was also made. The results show that Method B has the potentiality to evaluate the amount of combustion heat release of materials.

  • 35.
    Zaccone, Marta
    et al.
    Proplast, Via Roberto di Ferro 86, 15122 Alessandria, Italy.
    Patel, Mitul Kumar
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    De Brauwer, Laurens
    Bio Base Europe Pilot Plant (BBEPP), Rodenhuizekaai 1, 9042 Gent, Belgium.
    Nair, Rakesh
    Bio Base Europe Pilot Plant (BBEPP), Rodenhuizekaai 1, 9042 Gent, Belgium.
    Montalbano, Maria Luana
    Proplast, Via Roberto di Ferro 86, 15122 Alessandria, Italy.
    Monti, Marco
    Proplast, Via Roberto di Ferro 86, 15122 Alessandria, Italy.
    Oksman, Kristiina
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Mechanical & Industrial Engineering, University of Toronto, Toronto, ON M5S 3BS, Canada; Wallenberg Wood Science Center (WWSC), Luleå University of Technology, SE 97187 Luleå, Sweden.
    Influence of Chitin Nanocrystals on the Crystallinity and Mechanical Properties of Poly(hydroxybutyrate) Biopolymer2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 3, article id 562Article in journal (Refereed)
    Abstract [en]

    This study focuses on the use of pilot-scale produced polyhydroxy butyrate (PHB) biopolymer and chitin nanocrystals (ChNCs) in two different concentrated (1 and 5 wt.%) nanocomposites. The nanocomposites were compounded using a twin-screw extruder and calendered into sheets. The crystallization was studied using polarized optical microscopy and differential scanning calorimetry, the thermal properties were studied using thermogravimetric analysis, the viscosity was studied using a shear rheometer, the mechanical properties were studied using conventional tensile testing, and the morphology of the prepared material was studied using optical microscopy and scanning electron microscopy. The results showed that the addition of ChNCs significantly affected the crystallization of PHB, resulting in slower crystallization, lower overall crystallinity, and smaller crystal size. Furthermore, the addition of ChNCs resulted in increased viscosity in the final formulations. The calendering process resulted in slightly aligned sheets and the nanocomposites with 5 wt.% ChNCs evaluated along the machine direction showed the highest mechanical properties, the strength increased from 24 to 33 MPa, while the transversal direction with lower initial strength at 14 MPa was improved to 21 MPa.

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