聚乙烯/聚烯烃弹性体共混物的交联行为和形状记忆效应

Crosslinking behavior and shape memory effect of blends of polyethylene and polyolefin elastomer

将线型低密度聚乙烯(LLDPE)与聚烯烃弹性体(POE)共混,并引入2,5-二甲基-2,5二叔丁基过氧基己烷(DHBP)制备出具有三重形状记忆效应的交联共混物X-LLDPE/POE,利用DSC,DMA等方法研究了POE和DHBP含量对共混物性能的影响,并考察了共混物的形状记忆效应。实验结果表明,随POE或DHBP含量的增加,共混物的凝胶含量和交联密度均呈先增大后趋于稳定的趋势。随POE含量的增加,共混物的力学性能降低,但固定率和形变回复率可大幅提高。DHBP含量的增加对固定率影响不大,但可提高形变回复率。不同温度下发生大形变的共混物均有良好的回复效果。升温速率过快时,回复会产生滞后。

By blending linear low-density polyethylene(LLDPE)with polyolefin elastomer(POE)and introducing 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexane(DHBP)peroxide,a cross-linked blend(X-LLDPE/POE)with triple shape memory effect was prepared.The influence of POE and DHBP content on the properties and shape memory effect of the blends was investigated by DSC,DMA and other methods.The experimental results show that with the increase of POE or DHBP content,the gel content and crosslinking density of the blends both increase first and then tend to be stable.As the content of POE increase,the mechanical properties of the blends decrease,but the fixity ratio and deformation recovery ratio have been greatly improved.The increase of DHBP content can improve the deformation recovery ratio,but has little effect on the fixity ratio.The blends exhibite a good recovery behavior with large deformations at different temperatures.When the heating rate is too fast,the recovery of the material shows a hysteresis.