Polycarbonate (PC) is a polyester carbonate, carbonic acid itself is not stable, but its derivatives (such as phosgene, urea, carbonates and carbonate) has a certain stability.

According to the different structure of alcohol, polycarbonate can be divided into two types of aliphatic and aromatic.

Aliphatic polycarbonates. Poly ethylene carbonate, poly trimethylene carbonate copolymer, melting point and glass transition temperature of low intensity differences, cannot be used as a structural material; but use its biocompatibility and biodegradable characteristics of sustained release drug carrier, surgical suture, bone support and so on.