Investigation on the Structure and Performance of Polypropylene Sheets and Bi-axially Oriented Polypropylene Films for Capacitors  

作　　者：Chong Zhang Xi-Ying Dai Zhao-Liang Xing Shao-Wei Guo Fei Li Xin Chen Jian-Jun Zhou Lin Li 

机构地区：[1]State Key Laboratory of Advanced Power Transmission Technology,Global Energy Interconnection Research Institute Co.Ltd.,Beijing 102209,China [2]Beijing Key Laboratory of Energy Conversion and Storage Materials,College of Chemistry,Beijing Normal University,Beijing 100875,China

出　　处：《Chinese Journal of Polymer Science》2022年第12期1688-1696,I0011,共10页高分子科学（英文版）

基　　金：financially supported by the State Key Laboratory of Advanced Power Transmission Technology (No.GEIRI-SKL2020-009)。

摘　　要：Polypropylene(PP) sheets are cast with various chill roll temperatures and rates, which are studied with differential scanning calorimetry, wide angel X-ray diffraction, scanning electronic microscopy and dielectric withstand voltage test system. The results show that increasing the chill roll temperature and cast rate can promote the increase of crystallinity and the growth of β-form. The PP sheets have asymmetric skin layer structures. The lower the chill roll temperature, the thicker the skin layer, the smaller the spherulite size. The electric breakdown strength(Eb) of PP sheets is mainly affected by the crystallinity but not the morphology. The PP sheets are further stretched to prepare bi-axially oriented PP(BOPP) films with various heat setting time. Our results indicate that the structure of PP sheets affects the properties of BOPP films. The as prepared BOPP films from the sheets cast at high chill roll temperature and rate have the highest crystallinity and Eb. Heat setting time has profound effect on the crystallinity and Eb, which increase first and then decrease with the heat setting time. It is expected that our study can provide guidance for optimizing process parameters.

关 键 词：BOPP film Polypropylene sheet Electric breakdown strength CRYSTALLINITY Heat set 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业] TB383.2[一般工业技术—材料科学与工程] TM53[电气工程—电器]