A biocompatible, metal-free catalyst and its application in microwave-assisted synthesis of functional polyesters

Aliphatic polyesters are one of the most important classes of biodegradable materials. Convergence of functionality and biodegradability represents a major trend in modern materials, especially for biomedical applications and as environmentally friendly alternatives to non-degradable petrochemicals. However, the synthesis of functional polyesters is still a formidable challenge. Most current methods are inefficient and require complex chemical processes. We report a microwave-assisted, acid-initiated epoxide ring opening polymerization. With this one-step synthetic strategy, functional polyesters are produced within half an hour without generation of any byproduct. Thus, our approach represents a significant improvement over current methods by increasing efficiency, minimizing chemical processes, and reducing the usage of hazardous chemicals and waste. The newly designed catalyst, bis(tetrabutylammonium)sebacate, is a metal-free catalyst readily prepared under mild conditions at a large scale. The catalyst is stable and easily stored for more than 7 years under standard storage conditions. Additionally, the catalyst shows good cytocompatibility when tested using primary rat osteoblasts. We expect this technology will be very useful to produce new biodegradable materials. A novel synthetic strategy aided by a newly designed catalyst and microwave irradiation provides an efficient route to functional polyesters.