Macromolecules, Vol.45, No.23, 9275-9281, 2012
Semicrystalline Dihydroxyacetone Copolymers Derived from Glycerol
The ring-opening polymerization of glycerol-derived six-membered cyclic dimethylacetal dihydroxyacetone carbonate (MeO(2)DHAC) have been studied both in solution and bulk conditions with organic catalysts. The guanidine 1,5,7-triazabicyclo[4.4.0]clec-5-ene (TBD) was the most active catalyst in solution, whereas the thiourea/sparteine catalytic system displayed the most predictable kinetics. Ring-opening polymerization of MeO(2)DHAC or copolymerization with epsilon-caprolactone (CL) in the melt occurred readily with TBD as catalyst to afford random copolymers. Acetal deprotection afforded the polycarbonate poly(dihydroxyactone carbonate) (p(DHAC)) or poly(carbonate ester) copolymers p(DHAC-r-CL). The polycarbonate p(DHAC) is a high-melting thermoplastic with a melting point of 246 degrees C. The p(DHAC-r-CL) copolymers all displayed semicrystalline behavior as evidenced by DSC and WAXS analysis with T-8 and T-m changing as a function of comonomer composition. These new materials could have potential use in biomedical applications or as biomass-derived thermoplastics.