复合载体扩散/阻隔特性的调控与乙烯聚合反应器的强化  

Control of Diffusion/Barrier Effects of Polymer-Coated Particles and the Strengthening of Ethylene Polymerization Reactor

作　　者：杨勇[1] 历伟[1] 杜丽君[1] 蒋斌波[1] 王靖岱[1] 阳永荣[1] 

机构地区：[1]浙江大学化学工程与生物工程学系,化学工程联合国家重点实验室,浙江杭州310027

出　　处：《化学反应工程与工艺》2013年第3期260-268,共9页Chemical Reaction Engineering and Technology

基　　金：国家自然科学基金(21176208);国家高技术研究发展计划(863计划)(2007AA030208)

摘　　要：为在单一反应器中生产宽/双峰分子量聚乙烯,强化乙烯聚合反应过程,实现分子尺度混合的原位化学合成,并有效降低投资、生产成本和能耗。本工作提出制备一种具有扩散/阻隔特性的核壳结构颗粒作为聚烯烃催化剂的载体,并进行动力学特性的调控。即采用相转化制膜的方法,制备以硅胶(SiO2)为核、聚苯乙烯丙烯酸(PSA)为壳的核壳结构颗粒,然后通过浸渍法,将具有不同反应特性的催化剂活性分子分别组装在核壳结构颗粒中,获得负载型双功能催化剂。其关键技术是以PSA膜为小分子传递扩散的控制开关,利用乙烯、氢气分子和-烯烃分子在膜中扩散特性的差异,以及Cp2ZrCl2、TiCl3和TiCl4等活性组分在动力学上的差异,构建膜内、膜外两种微化学环境,使得活性组分在不同的气氛下分别制备低分子量、低支化的聚合物链和高分子量、高支化度的聚合物链,形成高性能双峰聚乙烯的新工艺。比较三种双峰聚乙烯反应器组合的能耗,表明在单一流化床中采用复合催化剂生产双峰聚乙烯产品能够强化乙烯聚合反应器,能耗大幅下降。同时,通过活性组分和膜厚的调节,实现对聚乙烯分子量分布的调控。In order to produce broad/bimodal molecular weight polyethylene in a single reactor, strengthen the ethylene polymerization process, to reduce the investment in production and energy consumption, and achieve the molecular scale mixing in situ chemical synthesis, a diffusion/barrier composite support was prepared to regulate and control properties of polyethylene. Based on phase inversion principle, spherical and well-dispersed polymer-coated particles （SiO2/PSA） were successfully prepared using silica （SiO2） and poly[styrene-co-（acrylic acid）] （PSA）. Then we successfully prepared supported hybrid catalysts with different catalyst divided by PSA layer. With ethylene, hydrogen and a-olefin diffuse differently in the PSA layer, and active components such as CpzZrClz, TIC13 and TiCI4 behave differently in dynamic, we construct two micro-chemical environment, inside and outside of the PSA layer, so that active component prepares low Mw, low branched polymer chains and high Mw, high branched polymer chains separately in different micro-chemical environment. Meanwhile, we could regulate the active component and the thickness of PSA layer to control the molecular weight distribution of polyethylene.

关 键 词：相转化法 核壳载体 阻隔效应 复合催化剂 宽 双峰聚乙烯 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业]