国外无规共聚聚丙烯专用料组成和结构的分析

利用傅里叶变换红外光谱、碳核磁共振光谱、示差扫描量热(DSC)分析和熔体流动指数对国外4种工业化生产的无规共聚聚丙烯(PP-R)专用料(1#,2#,3#,4#)进行了组成和结构分析。分析结果表明,PP-R专用料是由丙烯和乙烯无规共聚而成,在无规共聚物中不存在乙烯结晶。通过比较可知,4种PP-R专用料有相似的乙烯含量、结晶熔融温度和熔体流动指数,但从DSC恒温结晶分级实验观察到,4#专用料表现为大而宽的熔融峰,表明乙烯在聚丙烯主链上的分布是较均一的。同时乙烯的含量以及乙烯插入丙烯链中相连点的数目是控制PP-R专用料质量的关键。该结果可为提高国内PP-R专用料的质量提供参考。

Analysis of Composition and Microstructure of Imported Random Ethylene-Propylene Copolymer Special Resins

Composition and microstructure of four different imported commercial random ethylene-propylene copolymer(PP-R)special resins(1~#,2~#,3~#,4~#)were characterized by means of ~(13)C NMR,FTIR,DSC and melt flow index(MFI).The four PP-R special resins were propylene-ethylene random copolymers.There was no polyethylene crystal in PP-R special resins.Contents of ethylene in four(PP-R) special resins were same.Melting temperature and MFI of four samples were also similar.However,a strong and broad melting peak for 4~# sample could be observed by stepwise isothermal crystallization test,which showed that ethylene was homogenously distributed in polypropylene main chains.The optimum properties of PP-R special resins were:ethylene mole fraction 5%— 7%,melting temperature 140— 144℃,and MFI(10min)0.23— 0.28g(230℃,0.21MPa).