茂金属聚乙烯改性低密度聚乙烯中电荷入陷与传输特性

聚合物的电性能与其物理、化学、微观结构密切相关.通过电声脉冲(PEA)法测量少量茂金属聚乙烯(MPE)与低密度聚乙烯(LDPE)共混物在不同场强作用下的去极化特性.根据空间电荷限制电流(SCLC)理论,通过公式推导求解共混物平均电荷体密度、视在迁移率、陷阱深度分布及阈值场强.结果表明,1%MPE与LDPE共混,能有效减少深陷阱密度,增加浅陷阱密度,提高电荷迁移率和阈值场强.

Charge Trapping and Transport Properties in Low-Density Polyethylene Modified by Metallocene Catalyzed Polyethylene

Dielectric properties of polymer are related to its physical, chemical and microstructural structures. The depolarization characteristics of low-density polyethylene (LDPE) blended with a small amount of metallocene catalyzed polyethylene (MPE) are measured by pulsed electro-acoustic (PEA) method under various stresses. According to space charge limited current (SCLC) theory, the derivation of quantities such as mean volume density of space charge, apparent trap-controlled mobility, trap depth distribution and threshold stress is discussed. The test results show that LDPE blended with 1 wt% MPE can effectively decrease deep trap density, increase shallow trap density, and improve the mobility of charges and threshold stress.