Thermoplastic starch/PVAl compounds: Preparation, processing, and properties

As a renewable and native polymeric material, thermoplastic starch is gaini ng increased acceptance because of resource and environment concerns. This study reports the formulation design of native starch/polyvinyl alcohol (PV Al) compounds; the preparation technology to make them available for thermo plastic processing; and their rheological, mechanical, and degradation prop erties. Among various plasticizers investigated, a mixture of glycerin and water (50/50 wt %) is found to be the best one for the compounds in terms o f rheological behavior, mechanical properties, and environmental stability. The mechanical properties do not increase with the PVAl content to an expe cted extent, mainly due to the poor interface adhesion between the fibrous PVAl structure and the starch matrix. (C) 1999 John Wiley & Sons, Inc.