PPR管材专用料的结构与性能

采用核磁共振(NMR)、X衍射仪、差示扫描量热法(DSC)、凝胶渗透色谱(GPC)等分析技术对无规共聚聚丙烯(PPR)管材专用料的结构和性能进行研究,并且与国外料进行了对比。结果表明,PPR管材专用料具有典型的无规共聚物序列结构,PPE和PEP含量高,EEE含量低;乙烯较均匀地分布在共聚物链上,乙烯含量高的共聚物相对分子质量小,乙烯含量低的共聚物相对分子质量大,相对分子量分布宽;乙烯在丙烯聚合时无规插入,使无规共聚物结晶尺寸变小,结晶度、结晶速率和熔点均降低。使PPR管材专用料具有冲击韧性高、脆化温度低、化学稳定性强和优良的成型加工等宏观性能,其结构和性能指标与国外料相当。

Structure and Properties of the Special Random Copolymer of Propylene for Pipes

Structure and properties of the special random copolymer of propylene(PPR) for pipe were studied by NMR,XRD,DSC and GPC and compared with imported samples.The results show that PPR is a special resin for pipes and has random copolymer sequence structure,in which contents of PPE and PEP are high and content of EEE is low;Ethylene uniformly distributes in copolymer chains;Copolymers with high content of ethylene have lower relative molecular mass while copolymers with low content of ethylene have higher relative molecular mass and distribution of relative molecular mass is broad. Because of irregular entrance of ethylene into the molecule chain of the random copolymer,it's crystal dimention,crystallinity,crystallization velocity and melting point are decreased.These determine its outstanding performances such as high impact toughness,low temperature of the ductile to brittle transition,high chemical stability and excellent formability,so its structure and properties can be as equal as that of imported samples.