Catalytic synthesis and physical properties of CO2-based cross-linked poly(cyclohexene carbonate)s

Abstract

Bifunctional aluminum porphyrins (0.001 mol%) catalyzed the terpolymerization of cyclohexene oxide (CHO), bis(CHO), and CO₂ to give cross-linked polycarbonates (CLPs) under solvent-free conditions. A small amount of bis(CHO) acted as a cross-linking agent, and the use of only 0.1 mol% bis(CHO) to CHO produced polymers of quite large sizes. The thermal and mechanical properties of CLPs could be altered by changing the structure and amount of bis(CHO), and the CLPs showed improved thermal stability and tensile strength as compared to linear poly(cyclohexene carbonate)s (PCHCs). The degradation of the CLPs was also investigated, and the selective cleavage of the cross-links was achieved by UV light irradiation to give linear PCHCs. The present study disclosed the potentials of cross-linking terpolymerization for the preparation of various CLPs with a constant CO₂ content (31 wt%).