线型低密度聚乙烯的分级制备  

Fractionation and characterization of LLDPE

作　　者：张宁[1] 侯斌[1] 张博[1] 苏旭[1] Zhang Ning;Hou Bin;Zhang Bo;Su Xu(Institute of Qilu Petrochemical Co.,SINOPEC,Zibo 255400,China)

机构地区：[1]中国石油化工股份有限公司齐鲁分公司研究院,山东省淄博市255400

出　　处：《合成树脂及塑料》2018年第5期10-12,共3页China Synthetic Resin and Plastics

摘　　要：采用制备型升温淋洗分级仪对线型低密度聚乙烯(LLDPE)进行分级和收集,得到6个不同结晶度的级分,并利用差示扫描量热仪、傅里叶变换红外光谱仪、核磁共振波谱仪和凝胶渗透色谱仪分别对原样和级分的结晶熔融行为、短链支化度、相对分子质量及其分布进行了分析。结果表明:随着淋洗温度的升高,级分的结晶度增大、支化度降低、相对分子质量增大,且LLDPE试样中存在支化不均匀性,低相对分子质量部分聚乙烯的共聚单体含量较高,高相对分子质量部分聚乙烯的共聚单体含量较少。Linear low density polyethylene(LLDPE)was fractionated by preparative temperature rising elution fractionation(P-TREF)and six fractions with different crystallinity were collected.These fractions were characterized by differential scanning calorimeter,Fourier transform infrared spectroscope,nuclear magnetic resonance spectrometer,and gel permeation chromatograph in terms of crystallization melting behavior,short chain branching,relative molecular mass and its distribution.The results indicate that the crystallinity and relative molecular mass of the fractions increase gradually with the rise of the elution temperature,while the degree of branching decreases.The heterogeneity of branching occurs in LLDPE in which the content of comonomer is high in the part of low molecular mass and low in the part of high molecular mass.

关 键 词：线型低密度聚乙烯 升温淋洗分级 结晶度 支化度 不均匀性 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业]