Networks based on biodegradable polyesters: An overview of the chemical ways of crosslinking

Biodegradable polymers have gained more importance due to growing concern of our society for the ecology and sustainable development. Among them, aliphatic polyesters, poly(ε-caprolactone) PCL, poly(lactic acid) PLA and poly(3-hydroxyalkanoate)s PHAs present the advantage to be both biodegradable and biocompatible. Nevertheless, their thermal and mechanical properties represent a major drawback limiting some engineering applications. As a result the design of novel structures such as networks based on polyesters is revealing as a great challenge for enhancing their mechanical and thermal properties. The networks can be obtained throughout several approaches. This review focuses on the different chemical methods of crosslinking by using radical mechanisms, condensation reactions of polyesters or functionalized oligoesters. Preparation of hybrid, interpenetrated or reversible networks are described. This review highlights the relations structure-properties of the resulted materials and their potential applications.