流化床聚合反应器两种操作模式下乙烯共聚物的链结构与力学性能  

Chain Structure and Mechanical Properties of Ethylene Copolymers in Two Operating Modes of Fluidized Bed Polymerization Reactor

作　　者：胡晓波[1] 杨遥[1] 蒋斌波[1] 王靖岱[1] 阳永荣[1] Xiao-bo Hu;Yao Yang;Bin-bo Jiang;Jing-dai Wang;Yong-rong Yang(State Key Laboratory of Chemical Engineering,College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310027)

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

出　　处：《高分子学报》2021年第2期186-195,I0004,共11页Acta Polymerica Sinica

摘　　要：采用制备型升温淋洗分级方法,对流化床聚合反应器在持液操作模式和冷凝态操作模式下生产的A、B两种乙烯/1-丁烯/1-己烯三元共聚物进行了分级,并结合多种分析手段对样品及其各级份进行了结构表征,同时测试对比了A、B两种聚乙烯样品的力学性能.结果表明,与冷凝态操作模式生产的聚乙烯样品B相比,持液操作模式下生产的聚乙烯样品A的拉伸屈服强度、拉伸断裂强度、断裂伸长率、冲击强度和雾度都比样品B优异.样品A的低温淋洗级份相对含量低于样品B,而其高温淋洗级份相对含量高于样品B;样品A低温淋洗级份的分子量略低于样品B,而其高温淋洗级份的分子量高于样品B;样品A的薄片晶含量和厚片晶含量都比样品B多,同时样品A的片晶厚度分布比样品B宽;样品A的总支化度以及每个级份的支化度都比样品B高,且样品A的支链在分子链间的分布比样品B宽,即样品A的支链比样品B的支链更倾向于生长在高分子量部分.通过以上表征分析,发现持液操作模式下生产的样品A比冷凝态操作模式下生产的样品B的物理使用性能更加优异,适合制备高性能的拉伸缠绕膜.Two ethylene/1-butene/1-hexene terpolymers(sample A and sample B)produced in the fluidized bed polymerization reactor with two different operation modes were fractionated by prepared temperature rising elution fractionation(P-TREF),and the structures of obtained fractions were characterized by the gel permeation chromatography(GPC),differential scanning calorimetry(DSC),nuclear magnetic resonance(13C-NMR),and successive self-nucleation and annealing thermal analysis(SSA).Meanwhile,the tensile yield strength,tensile strength,impact strength,elongation and haze of these two sampled were also tested according to the National Standard of the People’s Republic of China.Results showed that compared with sample B produced in the condensed operation mode,the sample A produced in the liquid containing operation mode had better tensile yield strength,tensile strength,impact strength,elongation and haze.The relative content and the molecular weight of the low-temperature elution fraction of sample A was lower than those of sample B,but for high-temperature elution fraction,the relative content and the molecular weight of sample A were both higher than those of sample B.Sample A possessed the broader distribution of lamellar thickness than sample B.The distribution of short branches between molecular chains of sample A was also wider than that of sample B.From the analysis of branching degree and molecular weight,sample A’s short chain branches were more likely to grow in the high molecular weight chains than sample B.In summary,the sample A produced in the liquid containing operation mode has more excellent physical performance than sample B produced in the condensed operation mode,which was suitable for the preparation of high-performance stretch film material.

关 键 词：聚乙烯 持液操作 冷凝态操作 制备型升温淋洗分级 短支链分布 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业]