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Wallström, Lennart
Publikationer (10 of 38) Visa alla publikationer
Mannberg, P., Nyström, B., Wallström, L. & Joffe, R. (2014). Service life assessment and moisture influence on bio-based composites (ed.). Journal of Materials Science, 49(15), 5265-5270
Öppna denna publikation i ny flik eller fönster >>Service life assessment and moisture influence on bio-based composites
2014 (Engelska)Ingår i: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 49, nr 15, s. 5265-5270Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

A race towards a more sustainable society is going on worldwide and decreasing dependence on fossil resources in energy and transport sectors is main goals. One path to decreased oil usage is development of lightweight materials from renewable resources like bio-based composites. However these new bio-based materials have not only to compete in mechanical performance, they also have to restrain environmental loads like moisture and temperature over time. In this study two bio-based composites have been compared to an oil-based composite in terms of long-term properties and water absorption behaviour. The long-term behaviour is determined by dynamic mechanical thermal analysis, DMTA, and time temperature superposition, TTSP. The water uptake is determined by submersion of specimens into water and tracking their weight change over time. The moisture influence is characterised in form of water uptake and change in the master curves created by TTSP procedure. The results show that there is a significant difference in long-term performance between the bio-based and oil-based composites. It is realized that the bio-based composites can be a good alternative for some applications especially when taking their eco-friendly nature into account.

Nyckelord
Bio-based composites, Service life assessment, Time temperature superposition, Moisture absorption, Moisture induced ageing
Nationell ämneskategori
Kompositmaterial och -teknik
Forskningsämne
Polymera konstruktionsmaterial
Identifikatorer
urn:nbn:se:ltu:diva-6381 (URN)10.1007/s10853-014-8211-6 (DOI)000336032500004 ()2-s2.0-84901302887 (Scopus ID)49c8c2d8-8dd5-4f92-9f8a-4ed57dc274c6 (Lokalt ID)49c8c2d8-8dd5-4f92-9f8a-4ed57dc274c6 (Arkivnummer)49c8c2d8-8dd5-4f92-9f8a-4ed57dc274c6 (OAI)
Anmärkning

Validerad; 2014; 20140227 (joffe)

Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2022-04-02Bibliografiskt granskad
Hajlane, A., Kaddami, H., Joffe, R. & Wallström, L. (2013). Design and characterization of cellulose fibers with hierarchical structure for polymer reinforcement (ed.). Cellulose, 20(6), 2765-2778
Öppna denna publikation i ny flik eller fönster >>Design and characterization of cellulose fibers with hierarchical structure for polymer reinforcement
2013 (Engelska)Ingår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 20, nr 6, s. 2765-2778Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

This paper describes an approach to manufacture hierarchical composites from environmentally friendly materials by grafting cellulose whiskers onto regenerated cellulose fibers (Cordenka 700). Fourier Transform Infrared spectroscopy, Scanning Electron Microscopy and X-ray diffraction analysis were performed to verify the degree of modification. The mechanical properties of the unmodified and modified fibers were analyzed using fiber bundle tensile static and loading-unloading tests. To show the effect of cellulose whiskers grafting on the Cordenka fibers, epoxy based composites were manufactured and tensile tests done on transverse uni-directional specimens. The mechanical properties were significantly increased by fiber modification and addition of the nano-phase into composite reinforced with micro-sized fibers.

Nationell ämneskategori
Kompositmaterial och -teknik
Forskningsämne
Polymera konstruktionsmaterial
Identifikatorer
urn:nbn:se:ltu:diva-7954 (URN)10.1007/s10570-013-0044-y (DOI)000327123000010 ()2-s2.0-84888011467 (Scopus ID)664ede97-d530-47cb-9ae1-a4b76e0b7309 (Lokalt ID)664ede97-d530-47cb-9ae1-a4b76e0b7309 (Arkivnummer)664ede97-d530-47cb-9ae1-a4b76e0b7309 (OAI)
Anmärkning
Validerad; 2013; 20130911 (joffe)Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2022-05-10Bibliografiskt granskad
Hajlane, A., Kaddami, H., Joffe, R. & Wallström, L. (2013). Design and characterization of cellulose fibers with hierarchical structure for polymer reinforcement (ed.). Paper presented at EEIGM International Conference on Advanced materials research : 21/03/2013 - 22/03/2013. Paper presented at EEIGM International Conference on Advanced materials research : 21/03/2013 - 22/03/2013.
Öppna denna publikation i ny flik eller fönster >>Design and characterization of cellulose fibers with hierarchical structure for polymer reinforcement
2013 (Engelska)Konferensbidrag, Poster (med eller utan abstract) (Refereegranskat)
Abstract [en]

This paper describes an approach to manufacture hierarchical composites from environmentally friendly materials by grafting cellulose whiskers onto regenerated cellulose fibers (Cordenka 700). Fourier Transform Infrared spectroscopy, Scanning Electron Microscopy and X-ray diffraction analysis were performed to verify the degree of modification. The mechanical properties of the unmodified and modified fibers were analyzed using fiber bundle tensile static and loading-unloading tests. To show the effect of cellulose whiskers grafting on the Cordenka fibers, epoxy based composites were manufactured and tensile tests done on transverse uni-directional specimens. The mechanical properties were significantly increased by fiber modification and addition of the nano-phase into composite reinforced with micro-sized fibers.

Nationell ämneskategori
Kompositmaterial och -teknik
Forskningsämne
Polymera konstruktionsmaterial
Identifikatorer
urn:nbn:se:ltu:diva-32612 (URN)72a20743-22da-42ad-b122-cd646f3e1235 (Lokalt ID)72a20743-22da-42ad-b122-cd646f3e1235 (Arkivnummer)72a20743-22da-42ad-b122-cd646f3e1235 (OAI)
Konferens
EEIGM International Conference on Advanced materials research : 21/03/2013 - 22/03/2013
Anmärkning
Godkänd; 2013; 20130919 (andbra)Tillgänglig från: 2016-09-30 Skapad: 2016-09-30 Senast uppdaterad: 2023-09-06Bibliografiskt granskad
Arab, A., Stommel, L. & Wallström, L. (2013). Fibre Orientation Investigation in Short Natural Fibre Reinforced Composites Using Synchrotron Imaging (ed.). Paper presented at EEIGM International Conference on Advanced materials research : 21/03/2013 - 22/03/2013. Paper presented at EEIGM International Conference on Advanced materials research : 21/03/2013 - 22/03/2013.
Öppna denna publikation i ny flik eller fönster >>Fibre Orientation Investigation in Short Natural Fibre Reinforced Composites Using Synchrotron Imaging
2013 (Engelska)Konferensbidrag, Poster (med eller utan abstract) (Refereegranskat)
Nationell ämneskategori
Kompositmaterial och -teknik
Forskningsämne
Polymera konstruktionsmaterial
Identifikatorer
urn:nbn:se:ltu:diva-39966 (URN)eeaaf5c0-1cc6-4042-b010-7af8ffa11cd9 (Lokalt ID)eeaaf5c0-1cc6-4042-b010-7af8ffa11cd9 (Arkivnummer)eeaaf5c0-1cc6-4042-b010-7af8ffa11cd9 (OAI)
Konferens
EEIGM International Conference on Advanced materials research : 21/03/2013 - 22/03/2013
Anmärkning
Godkänd; 2013; 20130919 (andbra)Tillgänglig från: 2016-10-03 Skapad: 2016-10-03 Senast uppdaterad: 2023-09-06Bibliografiskt granskad
Warnes, W. H., Kruzic, J. J., Pratt, C. C., Stehr, C., Cann, D. P., Gibbons, B. J., . . . Wallström, L. (2013). Improving participation of engineering students studying abroad: An international dual-degree program in materials science and mechanical engineering (ed.). JOM: The Member Journal of TMS, 65(7), 840-845
Öppna denna publikation i ny flik eller fönster >>Improving participation of engineering students studying abroad: An international dual-degree program in materials science and mechanical engineering
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2013 (Engelska)Ingår i: JOM: The Member Journal of TMS, ISSN 1047-4838, E-ISSN 1543-1851, Vol. 65, nr 7, s. 840-845Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

By addressing two critical barriers that are known to prevent U.S. undergraduate engineering students from considering study abroad, namely, fitting the experience into highly structured engineering degree curricula and defraying the cost, recruitment of students can be quite satisfactory. Based on the unequal exchange of E.U. students participating in the program, it appears that the time to Bachelor's degree completion can be an important aspect for E.U. participation. With regard to the cost, the differential cost of participation compared to the students staying at their home university can be quite low (a few thousand dollars per year), making this type of program potentially affordable to sustain by providing small scholarships r stipends to the students. Finally, by partnering with foreign universities, OSU and UdS have been able to leverage their resources and provide the opportunity for students to pursue a Bachelor'sdegree in materials science or mechanical engineering, respectively.

Nationell ämneskategori
Kompositmaterial och -teknik
Forskningsämne
Polymera konstruktionsmaterial
Identifikatorer
urn:nbn:se:ltu:diva-4091 (URN)10.1007/s11837-013-0637-9 (DOI)000320387500006 ()2-s2.0-84879502755 (Scopus ID)1f592b18-c9f7-40b7-95df-3b9abeb7af6d (Lokalt ID)1f592b18-c9f7-40b7-95df-3b9abeb7af6d (Arkivnummer)1f592b18-c9f7-40b7-95df-3b9abeb7af6d (OAI)
Anmärkning

Validerad; 2013; 20130527 (andbra)

Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2022-04-12Bibliografiskt granskad
Arab, A., Stommel, M., Wallström, L. & Rack, A. (2013). Investigation of fibre degradation in natural fibre reinforced biocomposites (ed.). In: (Ed.), (Ed.), Proceedings of the 5th International Conference on Sustainable Materials, Polymers and Composites: Ecocomp 2013. Paper presented at International Conference on Sustainable Materials, Polymers and Composites : 03/07/2013 - 04/07/2013 (pp. 174-185).
Öppna denna publikation i ny flik eller fönster >>Investigation of fibre degradation in natural fibre reinforced biocomposites
2013 (Engelska)Ingår i: Proceedings of the 5th International Conference on Sustainable Materials, Polymers and Composites: Ecocomp 2013, 2013, s. 174-185Konferensbidrag, Publicerat paper (Refereegranskat)
Nationell ämneskategori
Kompositmaterial och -teknik
Forskningsämne
Polymera konstruktionsmaterial
Identifikatorer
urn:nbn:se:ltu:diva-31611 (URN)5d985440-e73c-4343-ba1f-662300bab365 (Lokalt ID)5d985440-e73c-4343-ba1f-662300bab365 (Arkivnummer)5d985440-e73c-4343-ba1f-662300bab365 (OAI)
Konferens
International Conference on Sustainable Materials, Polymers and Composites : 03/07/2013 - 04/07/2013
Anmärkning
Godkänd; 2013; Bibliografisk uppgift: CD-ROM; 20131202 (ysko)Tillgänglig från: 2016-09-30 Skapad: 2016-09-30 Senast uppdaterad: 2017-11-25Bibliografiskt granskad
Arab, A., Stommel, M., Wallström, L. & Varna, J. (2013). Stiffness prediction in green composites using homogenization techniques (ed.). In: (Ed.), (Ed.), Proceedings of the 19th International Conference on Composite Materials: ICCM 2013, Montreal (Canada). Paper presented at International Conference on Composite Materials : 28/07/2013 - 02/08/2013 (pp. 1214-1222).
Öppna denna publikation i ny flik eller fönster >>Stiffness prediction in green composites using homogenization techniques
2013 (Engelska)Ingår i: Proceedings of the 19th International Conference on Composite Materials: ICCM 2013, Montreal (Canada), 2013, s. 1214-1222Konferensbidrag, Publicerat paper (Refereegranskat)
Nationell ämneskategori
Kompositmaterial och -teknik
Forskningsämne
Polymera konstruktionsmaterial
Identifikatorer
urn:nbn:se:ltu:diva-38602 (URN)2-s2.0-85053187196 (Scopus ID)d0c0819e-a25c-4d0f-96a5-1f65d7881d7c (Lokalt ID)978-0-9696797-1-4 (ISBN)d0c0819e-a25c-4d0f-96a5-1f65d7881d7c (Arkivnummer)d0c0819e-a25c-4d0f-96a5-1f65d7881d7c (OAI)
Konferens
International Conference on Composite Materials : 28/07/2013 - 02/08/2013
Anmärkning
Godkänd; 2013; 20131202 (ysko)Tillgänglig från: 2016-10-03 Skapad: 2016-10-03 Senast uppdaterad: 2023-10-06Bibliografiskt granskad
Gopalakrishnan, P., Enqvist, E., Wallström, L., Gatlin, R. & Saiter, J. M. (2010). A new green thermoplastic polymer with improved hydrophobic character (ed.). Macromolecular Symposia, 290(1), 25-29
Öppna denna publikation i ny flik eller fönster >>A new green thermoplastic polymer with improved hydrophobic character
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2010 (Engelska)Ingår i: Macromolecular Symposia, ISSN 1022-1360, E-ISSN 1521-3900, Vol. 290, nr 1, s. 25-29Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

A green thermoplastic polymer based on wheat flour was modified by the addition of a natural crosslinker genipin. Films of the polymer modified with different composition of genipin were prepared by extrusion. Free surface energy using contact angle method, moisture absorption test and hardness test were used to characterize the products. From moisture absorption and contact angle measurements, it was seen that for genipin amounts higher than 0.2% w/w, a hydrophobic character is achieved. Results obtained indicate enhancement in hydrophobic properties of the films.

Nationell ämneskategori
Tribologi (ytteknik omfattande friktion, nötning och smörjning) Kompositmaterial och -teknik
Forskningsämne
Maskinelement; Polymera konstruktionsmaterial
Identifikatorer
urn:nbn:se:ltu:diva-8056 (URN)10.1002/masy.201050403 (DOI)000277250000004 ()2-s2.0-77950321252 (Scopus ID)67fa6290-4d27-11df-a0f4-000ea68e967b (Lokalt ID)67fa6290-4d27-11df-a0f4-000ea68e967b (Arkivnummer)67fa6290-4d27-11df-a0f4-000ea68e967b (OAI)
Anmärkning
Validerad; 2010; 20100421 (andbra)Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad
Hajlane, A., Sahib, A., Wallström, L., Joffe, R. & Kaddami, H. (2010). Design and characterization of cellulose fibers with highly hierarchical structure (ed.). Paper presented at Annual International SICOMP Conference : 03/06/2010 - 04/06/2010. Paper presented at Annual International SICOMP Conference : 03/06/2010 - 04/06/2010.
Öppna denna publikation i ny flik eller fönster >>Design and characterization of cellulose fibers with highly hierarchical structure
Visa övriga...
2010 (Engelska)Konferensbidrag, Poster (med eller utan abstract) (Övrigt vetenskapligt)
Nationell ämneskategori
Kompositmaterial och -teknik
Forskningsämne
Polymera konstruktionsmaterial
Identifikatorer
urn:nbn:se:ltu:diva-30266 (URN)407d0170-754d-11df-ab16-000ea68e967b (Lokalt ID)407d0170-754d-11df-ab16-000ea68e967b (Arkivnummer)407d0170-754d-11df-ab16-000ea68e967b (OAI)
Konferens
Annual International SICOMP Conference : 03/06/2010 - 04/06/2010
Anmärkning
Godkänd; 2010; 20100611 (joffe)Tillgänglig från: 2016-09-30 Skapad: 2016-09-30 Senast uppdaterad: 2018-01-16Bibliografiskt granskad
Nättinen, K., Hyvärinen, S., Joffe, R., Wallström, L. & Madsen, B. (2010). Naturally compatible: starch acetate/cellulosic fibre composites. Part I: Processing and properties (ed.). Polymer Composites, 31(3), 524-535
Öppna denna publikation i ny flik eller fönster >>Naturally compatible: starch acetate/cellulosic fibre composites. Part I: Processing and properties
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2010 (Engelska)Ingår i: Polymer Composites, ISSN 0272-8397, E-ISSN 1548-0569, Vol. 31, nr 3, s. 524-535Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Composite compounds based on hemp and flax fibers in triethyl citrate plasticized starch acetate were prepared by melt processing. For better properties and processability, compounds with plasticizer contents in the range 20-35 wt% were screened. Composites were prepared with fiber contents up to 50 wt%. The composite mechanical properties were measured from injection molded test specimens. A Young's modulus of 8.3 GPa and stress at maximum load of 51 MPa were obtained with 40 wt% flax fiber in a plasticized starch acetate with 20 wt% triethyl citrate. Decreasing the plasticizer and increasing the fiber content, the tensile properties were consistently improved. An almost linear relation between fiber content and the tensile properties was found. The increase of the fiber content first improved the impact strength, but at higher fiber contents resulted in a reduction of impact strength. The quality of the produced materials was found to be good; the variation in properties between duplicated compounds was acceptable low, the variation in density and fiber content along a single tensile specimen was low, and finally, the porosity content was low even at high fiber content. The latter result was verified with scanning electron microscope images of fracture surfaces of the composites.

Nationell ämneskategori
Kompositmaterial och -teknik
Forskningsämne
Polymera konstruktionsmaterial
Identifikatorer
urn:nbn:se:ltu:diva-11213 (URN)10.1002/pc.20833 (DOI)000275288500019 ()2-s2.0-76949106141 (Scopus ID)a21d9b80-96d6-11dd-aadc-000ea68e967b (Lokalt ID)a21d9b80-96d6-11dd-aadc-000ea68e967b (Arkivnummer)a21d9b80-96d6-11dd-aadc-000ea68e967b (OAI)
Anmärkning
Validerad; 2010; 20081010 (joffe)Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2018-07-10Bibliografiskt granskad
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