共聚聚丙烯中乙烯含量对材料力学和介电性能的影响

Effect of ethylene content on mechanical and dielectric properties of polypropylene copolymer

采用Ziegler-Natta催化剂合成了丙烯/乙烯共聚物,通过调节反应单体配比,合成了乙烯含量为2.9%~8.0%(x)的共聚聚丙烯。利用FTIR,^(1)H NMR,DSC,TG等方法表征了共聚物的结构和热性能,采用POM表征了共聚物的结晶形貌,研究了乙烯含量对共聚物材料力学性能和介电性能的影响。实验结果表明,乙烯能够提高共聚物的冲击强度,少量乙烯的引入能够显著提高材料的体积电阻率,但乙烯含量过高会使材料的体积电阻率下降、介电损耗增大。

Ziegler-Natta catalyst was used to synthesize propylene/ethylene copolymer.Polypropylene copolymers with ethylene content 2.9%-8.0%(x)were synthesized by adjusting the propylene/ethylene monomer ratio.The structure and thermal properties of the copolymers were characterized by FTIR and 1H NMR,DSC and TG.The copolymer crystalline morphology was characterized by POM.The effect of ethylene content on the mechanical and dielectric properties of copolymer was studied.The results show that ethylene unit could improve the copolymer impact strength,and the volume resistivity of copolymer increases significantly with the few addition of ethylene,while excessive addition of ethylene would cause the derease of volume resistivity and the increase of dielectric loss of copolymer.