Studies on mechanical properties of wood fiber reinforced cross-linked starch composites made from enzymatically degraded allylglycidyl ether-modified starch
2010 (English)In: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, Vol. 41, no 10, 1409-1418 p.Article in journal (Refereed) Published
In a previous work we introduced a new family of thermoset composites of softwood fiber and allylglycidyl ether modified potato starch (AGE-starch with a degree of substitution of 1.3 and 2.3) prepared by hot pressing. To improve the processability of AGE-starch with a DS = 1.3 (LDS-3) and to increase hygromechanical properties, the LDS-3 matrix has now been partially degraded by a-amylase at 45 degrees C (pH 6) for 0.5, 6 and 18 h. The study shows that already a 30 min enzymatic hydrolysis has a marked effect on the modified starch molecular weight and its thermal properties. The new composites with enzyme hydrolyzed AGE-starch, generically named D-LDS-3, showed good fiber dispersion and excellent interface between the fiber and matrix as studied by SEM. Premixes of D-LDS-3 matrix and fiber showed improved processability. The water vapor absorption was evaluated at 43.2% and 82.2% RH and the stiffness and strength properties were measured. The water uptake was shown to be reduced. The strength of neat matrix D-LDS-3-6 at ambient 68% RH reached 63 MPa and Young's modulus 3200 MPa and with 40 wt.% wood fiber reinforcement impressive 128 MPa and 4500 MPa, respectively.
Place, publisher, year, edition, pages
2010. Vol. 41, no 10, 1409-1418 p.
Starch/fiber composite, Cross linked, Mechanical testing, Moulding compounds
IdentifiersURN: urn:nbn:se:kth:diva-26695DOI: 10.1016/j.compositesa.2010.05.018ISI: 000281945800009ScopusID: 2-s2.0-78049420981OAI: oai:DiVA.org:kth-26695DiVA: diva2:373095
QC 201011302010-11-302010-11-262010-11-30Bibliographically approved