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采用稀土三元催化剂制备了二氧化碳-环氧丙烷-马来酸酐三元共聚物(PPCMA).用红外和核磁谱图确定了PPCMA的结构及马来酸酐单元的含量,3 wt%马来酸酐投料量的PPCMA(共聚物中马来酸酐单元含量4.1%)的玻璃化转变温度(Tg)和起始热分解温度(Td-5%)分别为13.4℃和217℃,拉伸强度为2.88 MPa,断裂伸长率为1669%,与二氧化碳-环氧丙烷共聚物(PPC)相比,引入少量马来酸酐的PPCMA有望成为一种韧性材料,并可对PPC和聚3-羟基丁酸酯(PHB)共混体系进行改性.当在PPC/PHB共混体系中添加10 wt%的PPCMA时,所得共混材料的拉伸强度为18.2 MPa,断裂伸长率则提高到85%,较没有添加PPCMA的样品提高了4.25倍,因此PPCMA的加入能有效提高PPC/PHB共混体系的韧性,改善PPC/PHB共混体系的力学性能.偏光显微镜的研究表明PPC/PHB共混体系加入PPCMA后,很快形成大量尺寸小的PHB球晶,且结晶速度大幅度提高,因此PPCMA在一定意义上可视为一种特殊的“成核剂”.
The carbon dioxide-propylene oxide-maleic anhydride terpolymer (PPCMA) was prepared by using a rare earth ternary catalyst.The structure of PPCMA and the content of maleic anhydride units were determined by IR and NMR spectra, and 3 wt% maleic anhydride feed The glass transition temperature (Tg) and initial thermal decomposition temperature (Td-5%) of the amount of PPCMA (maleic anhydride unit content in the copolymer of 4.1%) were 13.4 ° C and 217 ° C, respectively, and the tensile strength was 2.88 MPa, Elongation at Break is 1669%. PPCMA, which incorporates a small amount of maleic anhydride, is expected to be a ductile material compared to the carbon dioxide-propylene oxide copolymer (PPC) and can be used for PPC and poly 3-hydroxybutyrate (PHB ) Blend system.When 10 wt% PPCMA was added into the PPC / PHB blends, the tensile strength of the blends was 18.2 MPa and the elongation at break was increased to 85% PPCMA sample increased by 4.25 times, so the PPCMA added can effectively improve the toughness of PPC / PHB blends and improve the mechanical properties of PPC / PHB blends.Phosphorescence microscopy studies show that PPC / PHB blends added PPCMA, Quickly formed a large number of small size PHB spherulites, and the crystallization rate increased significantly, so PPCMA in a certain meaning On can be regarded as a special “nucleating agent .”