【作者】 马岩；

【导师】 胡立江；

【作者基本信息】 哈尔滨工业大学 ， 无机化学， 2006， 硕士

【摘要】 论文在概述和比较几种交联聚乙烯的生产工艺特点、一些商品化产品、交联工艺的新动态、市场前景以及介绍硅烷交联聚乙烯的反应原理、工艺路线、配方、产品性能和应用的基础上,系统地研究了硅烷接枝聚乙烯(SGPE)反应和SGPE的水解交联反应,表征了反应的动力学特性,考察了硅烷品种及用量的影响和作用机理,并讨论了接枝和交联反应中PE和SGPE分子和聚集态结构的变化和交联产物的结构-性能关系。在接枝反应过程中存在着少量的硅烷接枝聚乙烯分子链之间的水解缩合反应,熔体流动速率明显降低。SGPE反应遵循一级反应动力学,由DCP引发的VTMOS、VTEOS接枝低密度聚乙烯(LDPE)反应的活化能( )分别为170kJ/mol、185kJ/mol。不同体系的接枝反应速度及其温度、时间依赖性的差异,是其E_a不同所致。SGPE水解交联反应是关于催化剂和水分浓度的一级反应,其E_a=39.46kJ/mol。硅烷可交联聚乙烯(SCPE)具有一定的贮存期,在干燥状态可延长贮存期;同时,如果不经水煮,SCPE完全暴露在空气中长时间也可获得满意的交联度。催化剂的催化活性DBTDL>DMTBL>HSt>EAA。接枝和交联反应中LDPE结构的主要变化是线形大分子的支化和网络化,伴随结晶度下降和晶粒细化。交联产物的性能取决于上述结构变化的综合效应。随着体系凝胶含量的增加,体积电阻率逐渐上升,但当交联过度时,则呈下降趋势。随着体系凝胶含量的增加,体系的介电常数逐渐升高。更多还原

【Abstract】 The production presses and their key points of several crosslinked polyethylene materials, their some commercial products the recent advances of the crosslinking techniques, applications and marked prospect were summarized and compared. The reaction mechanism, technological process, prescription, product properties, and application of the crosslinked polyethylene by silane have been presented in the article. The graft reactions of polyethylene by silane (SGPE) and its crosslinking reaction were studied systematically and the reaction kinetics were characterized. The effects of concentration of silanes and their mechanism on reaction were investigated. The structure changes of the molecular and aggregate state in the grafting and crosslinking reaction and the relationship between the structure and properties were inspected in detail.In the process of graft the reactions of hydrolytic condensation among the silane grafted polyethylene molecular chain occurred, melt flow rate evidently decreased. The reaction of SGPE follows first order reaction kinetics. The reaction activation energy (E_a) of low density polyethylene (LDPE) grafted by vinyl trimethoxysilane (VTMOS) and vinyl triethoxysilane (VTEOS) initiated by dicumyl peroxide (DCP) are 170 and 185kJ/mol respectively. The grafting reaction velocity and its temperature and time-dependent behavior are controlled by their E_a.The crosslinking reaction of SGPE hydrolyzed water decomposition follows first order reaction kinetics on the content of initiator and water and its activation energy is 39.46kJ/mol. The cross-linkable polyethylene by silane (SCPE) can lay up a period and can prolong the storage period in the dry environment. At the same time, if not boiled by water, the SCPE exposed to the air completely during a long time also can acquire a better degree of crosslinking. The catalytic activity relationship DBTDL>DMTBL>HSt>EAA exists between the different catalyst.The major structure changes of LDPE during the grafting and crosslinking reaction are the grafting and netting of linear macromolecular, the decrease of the degree of crystallization and the thinning of crystal. The properties of crosslinked materials depend on these structure changes. Along with the increment of the gel更多还原