管式工艺中引发剂对低密度聚乙烯性能的影响  

Effects of Initiators on the Properties of Low-density Polyethylene in the Tubular Processes

作　　者：邸麟婷 慕雪梅[1] 王文英[1] 秦晨元 魏福庆[1] 许慧芳[1] 陈雷[2] 孙启虎 杨世元[1] DI Linting;MU Xuemei;WANG Wenying;QIN Chenyuan;WEI Fuqing;XU Huifang;CHEN Lei;SUN Qihu;YANG Shiyuan(Lanzhou Petrochemical Research Center,Petrochemical Research Institute,PetraChina,Lanzhou 730060,China;China Petroleum Daqing Petrochemical Company,Daqin 163000,China)

机构地区：[1]中国石油天然气股份有限公司兰州化工研究中心,甘肃兰州730060 [2]中国石油天然气股份有限公司大庆石化分公司,黑龙江大庆163000

出　　处：《塑料工业》2024年第12期17-22,共6页China Plastics Industry

摘　　要：低密度聚乙烯(LDPE)树脂以其优异的介电性能被广泛地应用于电气绝缘材料中。现有研究主要关注LDPE的介电性能、加工工艺和环境因素的影响,然而对引发剂的选择如何影响LDPE的结构性能的研究较少。本研究通过对比氧气和过氧化物分别作为引发剂的高压管式生产工艺,分析了2种引发剂条件下生产的LDPE(22E型和2240型)的分子结构、力学性能、介电性能和流变特性。结果表明,22E具有更大的数均分子量和更高的多分散性指数,但其熔体强度低于2240H,原因在于2240H的高支化度增加了分子链间的缠结,从而增强了熔体的弹性和黏弹性行为。2240H在170和190℃下的熔体强度显著高于22E,且其加工能耗较低,凝胶含量更高,表明2240H的交联密度较大。综上,过氧化物引发剂生产的LDPE(2240H)具有更高的支化度和熔体强度,而氧气引发剂生产的LDPE(22E)则具有更优异的介电性能和力学强度,本研究为高压管式工艺优化提供了理论支持。Low-density polyethylene(LDPE)resin is widely used in electrical insulation materials due to its excellent dielectric properties.Current researches mainly focus on the dielectric properties,processing technologies,and environmental factors of LDPE,but there are less researches on how the initiator choice affects the structural properties of LDPE.The high-pressure tubular production processes using oxygen or a peroxide as the initiator were compared,then the molecular structures,mechanical properties,dielectric properties,and rheological characteristics of LDPE(22E and 224OH)produced under the two initiator conditions were analyzed.The results show that 22E has a larger number-average molecular weight and a higher polydispersity index,but its melt strength is lower than that of 2240H.The reason is that the high degree of branching of 2240H increases the entanglements between molecular chains,enhancing the melt elastic and viscoelastic behaviors.The melt strengths of 2240H at 170 and 190℃are significantly higher than that of 22E,and the processing energy consumption of 2240H is lower.The gel content of 2240H is higher,indicating a higher crosslinking density of 2240H.In summary,LDPE(2240H)produced with the peroxide initiator has higher degree of branching and melt strength,while LDPE(22E)produced with the oxygen initiator exhibits superior dielectric properties and mechanical strength.This study provides theoretical supports for optimizing the high-pressure tubular process.

关 键 词：低密度聚乙烯 氧气引发剂 过氧化物引发剂 管式工艺 分子结构 

分 类 号：TQ320.61[化学工程—合成树脂塑料工业]