Abstract
Two type of poly (lactic acid)(PLA)/copoly (ethylene sebacate/hexamethylenesebacate) block polymer and their composites blended with 10% and 30% calcium phosphate, and poly (latic acid) as a control were examined for their degradability in vitro.The film samples were immersed in a phosphate buffer solution (pH7.4) at 37℃ for up to one year and changes in water absorption, tensile strength, molecular weight, and thermal properties of the films were followed over time. The changes in these properties varied with type of the block polymers and calcium phosphate content in the composites. Degradation of the polymers tended to be accelerated with increases in the content of the copolysebacate and to be retarded with increases in the calcium phosphate content.DSC analysis of the films revealed that crystallization of the polymers was involved in degradation.The present study suggested that preparation of various materials having different degradability is feasible by varying the PLA and copolysebacate ratio in the block polymer and by blending calcium phosphate with the block polymer.
