PROPERTIES OF OCTANOATED STARCH AND ITS BLENDS WITH POLYETHYLENE

Octanoated starch (OCST) was prepared by esterification of native star ch with octanoyl chloride. The new material was characterised by H-1 N MR, FTIR, and elemental analysis. This showed that the esterification had proceeded to a degree of substitution of 2.7. The octanoated starc h was subsequently mixed with low density polyethylene (LDPE) at vario us proportions in a Haake Rheomixer. Similar blends of LDPE were also prepared with plasticised starch (PLST) for comparison purposes. The t hermomechanical properties were determined as a function of blend comp osition. The prepared LDPE/OCST blends show better mechanical properti es compared to their respective LDPE/PLST blends. In particular, the e longation at breaking is significantly higher in the LDPE/OCST blends. The latter exhibit also a higher thermal stability and a low water ab sorption. Copyright (C) 1997 Elsevier Science Ltd. All rights reserved .