Synthesis and characteristics of a novel aliphatic polycarbonate, poly[(propylene oxide)-co-(carbon dioxide)-co-(γ-butyrolactone)]

A novel aliphatic polycarbonate, poly[(propylene oxide)-co-(carbon dioxide)-co-(gamma-butyrolactone)] [P(PO-CO2-GBL)], was synthesized by the copolymerization of carbon dioxide, propylene oxide (PO) and gamma-butyrolactone (GBL). The resulting copolymers were determined by FTIR and NMR spectral analysis with viscosity-average molecular weights (M-v) from 50000 to 120000 g mol(-1). According to elemental analysis, the calculated data of elemental contents in P(PO-CO2-GBL)44 were close to the found data. The result showed that GBL was inserted into the backbone of poly[(propylene oxide)-co-(carbon dioxide)] successfully. GBL offered an ester structural unit that gave the copolymer better degradability. The correlations between reaction conditions and properties were studied. When GBL content increased, the M-v and the glass transition temperature (T-g) of the copolymers improved relative to an identical copolymer without GBL. Prolonging the reaction time of the copolymerization resulted in increases in M-v and T-g. P(PO-CO2-GBL) exhibited a high T-g above 40 degrees C. The rate of backbone degradation increased with increasing GBL content. (c) 2005 Society of Chemical Industry.