二氧化碳/环氧丙烷/γ-丁内酯的三元共聚合和表征

CHARACTERIZATION AND TERPOLYMERIZATION OF CARBON DIOXIDE/PROPYLENE OXIDE/γ-BUTYROLACTONE

通过二氧化碳(CO2 )、环氧丙烷(PO)与γ- 丁内酯(GBL)的三元开环共聚反应,得到一种三元共聚物,脂肪族聚碳酸酯(PPCG) .对PPCG的结构进行了FTIR、1 H- NMR及1 3C -NMR表征,表明GBL被开环嵌入PO CO2分子链中,使得共聚物中引入了易水解的羧酸酯单元.对PPCG的热性能、降解性能进行了测试.结果表明,在一定范围内,随着γ丁内酯单元的增加,特性粘数降低,PPCG的玻璃化转变温度升高,材料降解性增强;不同的聚合反应时间对PPCG的特性粘数和和玻璃化转变温度也有着明显的影响.

Carbon dioxide is the primary contamination in the atmosphere.In order to reduce the pollution caused by CO 2,some methods have been developed to us e CO 2 as the raw material to produce degradable polymeric materials.A new aliphatic polycarbonate (PPCG) was succ essfully synthesized with terpolymerization of carbon dioxide,propylene oxide ( PO) and γ-butyrolactone (GBL).The copolymer was characterized by means of FTIR, 1H-NMR and 13C-NMR.The results showed that the ring of GB L was opened and inserte d into the chain of PO-CO 2. GBL offered an ester structural unit making the copo lymer easier to be hydrolyzed.The intrinsic viscosity,viscosity-average molecul a r weight (M v),and glass-transition temperature (T g) of copolymers w ere determined.PPCG exhibited a T g of around 40℃,which is higher than tha t of PPC.The influence of reaction time and ratio of PO∶GBL (mol/mol) on M v and T g of copolymer were tested.The increase of reaction time may resu l t in higher M v and T g.The total weight loss was used to characterize the degradation ability in hydrolysis tests.It was concluded that copolymers of high GBL content exhibited good degradabilidy.