Physical properties of aliphatic polycarbonates made from CO2 and epoxides

摘要

A homologous series of aliphatic polycarbonates with different side-chain lengths was synthesized by ring-opening polymerization of terminal epoxides with CO2 using zinc adipionate as catalyst [patented process of Empower Materials (formerly PAC Polymers Inc.)]. Additionally, a polycarbonate was made having a cyclohexane unit in its backbone, together with a terpolymer having both cyclohexane and propylene units. After characterization of thermal properties the aliphatic polycarbonates were found to be completely amorphous. Polycarbonates derived from long-chain epoxides showed a glass-transition temperature (T,,) below room temperature, whereas polycarbonates derived from cyclohexene oxide showed a T-g of 105degreesC, the highest yet reported for this class of polymers. The initial decomposition temperature of the polymers in air and nitrogen atmospheres was found to be less than 300degreesC. The mechanical properties and the dynamic mechanical relaxation behavior of the polymers were also reported. The effect of the chemical structure on the physical properties of aliphatic polycarbonates was discussed. (C) 2003 Wiley Periodicals. [References: 11]