Rigid Polyurethanes, Polyesters, and Polycarbonates from Renewable Ketal Monomers

Two novel biobased diols containing rigid cyclic ketal functionalities have been synthesized on a relatively large scale from glycerol and two diketones, i.e., 1,4-cyclohexanedione and 4,4'-bicyclohexanone. The diols have been used in several types of step growth reactions, resulting in polycarbonates, polyesters, and polyurethanes. While molecular weights (M-n) of up to 50 kg mol(-1) are obtained for the polyurethanes, they also exhibit high glass transition (T-g = 95-150 degrees C) and degradation temperatures (T-d = 260-320 degrees C), are transparent, and show a high mechanical strength (E = 1.10-1.35 GPa) but brittle behavior. For the polycarbonates, M-n values higher than 24 kg mol(-1) and T-g's in the range of 70-100 degrees C have been obtained. Moreover, the polycarbonates show good mechanical properties like ductility and are transparent. Finally, a new generation of fully renewable polyesters have been synthesized with dimethyl succinate and dimethyl furan dicarboxylate. While moderate molecular weight values are obtained, the polyesters show T-g's of up to 96 degrees C as well as high T-d's (+/- 315 degrees C).