Bulk composites from microfibrillated cellulose-reinforced thermoset starch made from enzymatically degraded allyl glycidyl ether-modified starch
2012 (English)In: Journal of composite materials, ISSN 0021-9983, E-ISSN 1530-793X, Vol. 46, no 25, 3201-3209 p.Article in journal (Refereed) Published
Microfibrillated cellulose consists of nanoscale bundles of elementary microfibrils prepared, e.g. by the defibrillation of delignified wood pulp fibres in high-pressure homogenizers. In this study, microfibrillated cellulose was used to reinforce a thermoset starch plastic. The starch was modified with allyl glycidyl ether with a degree of substitution of 1.3, which was further hydrolyzed with alpha-amylase for 18 h yielding significantly improved processing properties. Dry premixes of all constituents were prepared by a stepwise drying process before sample manufacturing. The composite was cured by ethylene glycol dimethacrylate initiated with benzoyl peroxide during compression moulding at 150 degrees C. Scanning electron microscopy revealed some degree of porosity in the samples, where the dispersed microfibrillated cellulose network was detectable. Microfibrillated cellulose, even in relatively small additions (2 wt%, 5 wt% and 10 wt%), resulted in composites with rather good hygromechanical properties. The ultimate strength increased with microfibrillated cellulose content and reached values of comparable composites with 40 wt% softwood fibre. Importantly, the dimensional stability in water was much improved compared to similar composites reinforced with substantially larger weight fractions of softwood fibres.
Place, publisher, year, edition, pages
2012. Vol. 46, no 25, 3201-3209 p.
Polymer-matrix composites, nanocomposites, mechanical properties, curing, scanning electron microscopy
Engineering and Technology
Research subject Engineering science with specialization in Applied Mechanics
IdentifiersURN: urn:nbn:se:uu:diva-190324DOI: 10.1177/0021998312437000ISI: 000311684100009OAI: oai:DiVA.org:uu-190324DiVA: diva2:585881