关键词：聚羟基烷酸酯；PHA；微生物聚酯
摘 要：Polyhydroxyalkanoates (PHAs) have been extensively investigated as biomaterials due to their good biocompatibility. However, the intrinsic hydrophobicity of PHAs, their hydrolytic stability under physiological conditions and lack of chemical functionalities restrict their biomedical applications. In order to widen the applications of PHAs, it is important to improve its properties such as mechanical, crystallinity, surface features, amphiphilicity and degradation rate. A useful strategy to improve the properties of PHAs is chemical modification, where functional groups are introduced to PHAs which cannot be normally achieved by bioconversion processes. In this chapter, well-established chemical modification methods of PHAs are summarized and discussed. Firstly, the preparation of PHAs functionalized by chemical processes of hydroxylation, carboxylation, epoxidation, chlorination, and thermal degradation at different temperatures are reviewed. Next, PHAs functionalization by graft copolymerization is described with respect to three important synthesis approaches: "graft onto", "graft from" and "graft through". Finally, the modification of PHAs by block copolymerization, with recent advances in literature, will be described through ester formation, urethane formation, and other formations prepared by atom transfer radical polymerization (ATRP) and "click" chemistry reactions. The biomedical significance of the functionalized PHAs in different areas will also be discussed.