Innovative biodegradable materials based upon starch and thermoplastic poly(ester-urethane) (TPU)

This paper shows the susceptibility of thermoplastic poly(ester-urethane) to hydrolysis and biodegradation. Following the storage of suitable samples in a water bath at different temperatures their mass loss, reduction in tensile strength, DSC-analysis and rheological measurements can be used to demonstrate the polymer degradation. Furthermore the biodegradability was investigated in different active environments using various test set-ups such as aqueous systems at different temperatures using a modified manometric respirometer, mature compost as well as a fresh compost. A significant rate of biodegradation occurs in all systems, the speed of which can be significantly increased to meet the criteria set out by the latest DIN-draft by incorporating starch. It is possible to incorporate up to 70% (w/w) of native starch into these hydrophilic matrices, which is important for the production of compostable materials for solid products. Compounds and especially blends consisting of TPU and thermoplastic starch (TPS) containing 50% (w/w) starch can be used to produce good sheets. (C) 1998 Elsevier Science Limited. All rights reserved.