New biodegradable polymers from renewable sources:: Polyester-carbonates based on 1,3-Propylene-co-1,4-cyclohexanedimethylene succinate

alpha,omega -Dihydroxy-terminated copolymeric oligomers of a 1,3-propylene/1,4-cyclohexanedimethylene succinate structure were obtained by the thermal polycondensation of 1,3-propanediol/1,4-cyclohexanedimethanol/s acid mixtures. They were subsequently chain-extended via phosgene synthesis to high molecular weight aliphatic/alicyclic copolyester-carbonates. These new polymers, besides having a biodegradable backbone, originate from two monomers, namely, 1,3-propanediol and succinic acid, which can be obtained by renewable sources. Therefore, they have a potential as environmentally friendly materials. All synthesized materials were characterized in reference to their molecular structure by H-1 NMR and C-13 NMR. Their molecular weights and molecular weight distributions were determined by size exclusion chromatography, and their main thermal properties were measured by DSC. Spectroscopic characterizations were in full agreement with the proposed structures. 1,4-Cyclohexanedimethanol was used as a diol comonomer to improve the overall thermal properties of poly(1,3-propylene succinate). The results of the characterization performed show that the initial expectations were only partially satisfied. (C) 2001 John Wiley & Sons, Inc.