Blends of Thermoplastic Starch Modified by Reactive Extrusion

Abstract

Thermoplastic starch (TPS) is a low cost biodegradable material with great potential for applications in the composition of biodegradable plastics. Several studies have been described with the objective of improve its properties, in particular its low water resistance, low mechanical properties and low miscibility and/ or compatibility with other commercial polymers. These characteristics make it difficult its application in the biodegradable plastic production. One alternative to improve its properties is its compounding with other polymers to form blends. However, when the chemical nature of the materials to be combined is very different it is necessary to use compatibilizers ou to promote reactions between the polymers during extrusion, process named reactive compatibilization. The main objective of this project is the study a process of depolimerization and polymerization of starch by reactive extrusion. The project target is the production of new materials formed from the polymerization of starch, with plasticizers and other compounds such as citric acid. It will also be objective of this project to investigate the miscibility and compatibility of TPS blends with poly(lactic acid) and biodegradable polyesters of 1,4- butanodiol. This project is inserted in the scope of the project FAPESP No. 2007/08394-7 "Modificação do Amido Termoplástico por Extrusão Reativa (REX): Compatibilização Reativa e Modificação Química via Despolimerização/ polimerização/ Thermoplastic starch modification by reactive extrusion (REX): Reactive Compatibilization and chemical modification via depolimerization/polimerization "), which is under course in our research group.