采用热拉伸-高温退火-冷拉的拉伸工艺制备了交联聚乙烯微孔膜，考察了交联聚乙烯的交联度、拉伸温度、退火温度和冷拉等工艺条件对交联聚乙烯微孔膜成孔性能的影响，并对成孔过程和机理进行了探讨。交联聚乙烯的交联度显著影响成孔性能，随着交联度的增加，成孔性增加。拉伸温度在90℃-120℃时，膜片基本由纤维状晶构成。拉伸温度升至130℃，并在此温度进行高温退火处理，膜片开始出现细缝状微孔。施加冷拉可以调控细缝状微孔形态演变，进一步被拉伸成圆形或椭圆洞状微孔。本文所用拉伸工艺为制备高性能聚乙烯微孔膜提供了一种新的思路，有助于开发自主知识产权的聚乙烯微孔膜技术，突破锂离子电池隔膜等高端聚乙烯微孔膜的国外技术垄断。

Cross-linked polyethylene microporous membranes were prepared by a new stretching process including hot stretching, high temperature annealing and cold drawing. The process conditions such as cross-linking degree, stretching temperature, annealing temperature and cold drawing of cross-linked polyethylene were investigated. The effect of the pore-forming performance of polyethylene microporous membrane, the pore-forming process and mechanism were discussed. The degree of cross-linking of cross-linked polyethylene significantly affects the pore-forming performance. As the degree of cross-linking increases, the porosity increases. When the stretching temperature is between 90 ° C and 120 ° C, the membrane is basically composed of fibrous crystals. The stretching temperature was raised to 130 ° C and high-temperature annealing treatment was performed at this temperature, the film began to appear fine slit-shaped micropores. The application of cold-drawing can regulate the morphological evolution of the slit-shaped micropores, which are further stretched into circular or elliptical micropores. The new stretching process provides a new idea for the preparation of high-performance polyethylene microporous membranes.

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