These polymers are becoming increasingly important in a range of applications including medical implants and drug delivery devices on one hand and disposable packaging and plastic consumer products on the other.
The most widely used polymers for these applications are the aliphatic polyesters and the most important single polymer is poly(lactic acid) or polylactide (PLA). How ever the usefulness of this polymer is limited by it price, mechanical and physical properties, not least because there is a wide range of applications and each has its own specific requirement for a balance of properties.
The purpose of this research is to extend the range of properties of PLA by the use of blending techniques, specifically the use of three component blends. This has entailed the investigation of structural analogues of PLA, including the other members of the poly(a-ester) family.
A critical aspect of these investigations is the question of polymer compatibility, or more particularly polymer miscibility. The project uses practical approaches such as those developed by Coleman and Painter in order to understand and rationalize the experimental results obtained on polymer blends and to provide a guide to the selection of candidate biodegradable polymers for subsequent blending studies. Because the study of structural effects in the miscibility of polyester blends has entailed the synthesis of novel poly a-ester analogues of PLA a rapid preliminarily screening method for very small (mg-range) quantities of polymers been developed. This solvent blending technique serves as a valuable preliminary step to subsequent melt blending studies.