【文章推荐】2018年第2期——交叉分级技术在高密度聚乙烯支链结构研究中的应用

中国塑料杂志社 2020-11-29 07:41:26

DOI:10.19491/j.issn.1001-9278.2018.02.020


收稿日期:2017-09-15


联系人,dubin010@petrochina.com.cn

标准与测试


交叉分级技术在高密度聚乙烯支链结构研究中的应用


杜斌1,陈商涛1,周京生1,张丽洋1,朱光宇1,陈兴锋2,王艳芳1,黄强1

(1.中国石油石油化工研究院,北京 102206;2.中国石油广西石化分公司,广西 钦州 535000)


摘要: 以高密度聚乙烯(PE-HD)为研究对象,采用多种不同的分级方法对树脂进行了分级,研究了树脂的支链结构及其分布,通过升温淋洗分级法与其他技术结合的交叉分级法,建立了短链支化含量、淋洗温度、相对分子质量的三维关系图,反映了PE-HD支链结构的分布特征。结果表明,PE-HD树脂由4部分构成:含有一定数量支链的低分子蜡部分;短支链数目较多的线形低密度聚乙烯部分,此部分随相对分子质量的增大支化度增加,且分布在高相对分子质量部分的支链含量较高;短支链数目较少的高密度聚乙烯部分,此部分短支链在不同相对分子质量区域的分布较为均匀;几乎不含支链的线形聚乙烯部分。

关键词: 高密度聚乙烯;交叉分级;支链结构;相对分子质量


Application of Cross-fractionation Technology in Study of Branch Structure of High-density Polyethylene


DU Bin1, CHEN Shangtao1, ZHOU Jingsheng1, ZHANG Liyang1,ZHU Guangyu1, CHEN Xingfeng2, WANG Yanfang1, HUANG Qiang1

(1.Petro China Petrochemical Research Institute, Beijing 102206, China;2.PetroChina Guangxi Petrochemical Company, Qinzhou 535000, China)


Abstract:The high-density polyethylene (PE-HD) resin was fractionated by different methods, and its branch structure and distribution were investigated. A three-dimensional relationship graph for the short-chain branching content, elution temperature and molecular weight was established by a combination of temperature rising elution fractionation and other cross-fractionation methods, which well reflected the branch-structural distribution characteristics of PE-HD. The results indicated that the PE-HD resin was composed of four parts including a low molecular wax containing a certain amount of branch structure, a part of linear low-density polyethylene with larger short-chain branching numbers, a part of high-density polyethylene with small short-chain branching numbers, and the linear polyethylene almost without any branching chains. It was also found that the fraction of the linear low-density polyethylene increased with an increase of relative molecular weight, whereas the part of the high-density one kept a uniform molecular weight distribution.

Key words:high-density polyethylene; cross-fractionation; branching structure; molecular weight


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