高等学校化学学报 ›› 2012, Vol. 33 ›› Issue (02): 430.doi: 10.3969/j.issn.0251-0790.2012.02.039

• 高分子化学 • 上一篇    

抗冲共聚聚丙烯及其级分的流变学研究

张春晖, 上官勇刚, 谭业强, 陈峰, 黄真芝, 郑强   

  1. 浙江大学高分子科学与工程系, 高分子合成与功能构造教育部重点实验室, 杭州 310027
  • 收稿日期:2011-02-11 出版日期:2012-02-10 发布日期:2012-01-13
  • 通讯作者: 上官勇刚, 男, 博士, 副教授, 主要从事多组分聚合物体系结构与性能及流变学研究. 郑 强, 男, 博士, 教授, 博士生导师, 主要从事多组分聚合物体系结构与性能及流变学研究. E-mail:shangguan@zju.edu.cn;zhengqiang@zju.edu.cn
  • 基金资助:

    国家"九七三"计划项目(批准号: 2005CB623800)和浙江省自然科学基金(批准号: Y4100314)资助.

Rheological Behavior of Impact Polypropylene Copolymer and Its Fractions

ZHANG Chun-Hui, SHANGGUAN Yong-Gang, TAN Ye-Qiang, CHEN Feng, HUANG Zhen-Zhi, ZHENG Qiang   

  1. Key Laboratory of Macromolecular Synthesis and Functionalization, Ministry of Education, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
  • Received:2011-02-11 Online:2012-02-10 Published:2012-01-13

摘要: 比较了抗冲共聚聚丙烯(IPC)和等规聚丙烯(iPP)熔体的动态流变行为, 确定了IPC的乙丙无规共聚物(EPR)、乙丙嵌段共聚物(EbP)和丙烯均聚物(HPP)3种级分的熔体动态流变行为. 研究发现, IPC在低频区域表现出偏离经典线性黏弹性理论的行为, 即出现了"第二平台". 经过二甲苯完全溶解的IPC试样的熔体流变行为研究结果表明, IPC分散相的团聚会提高熔体的模量. 对IPC 3种级分的动态流变行为的研究结果表明, 各级分间的动态储能模量(G')及黏度存在明显差异, 这主要是由于分子量和分子链链长的不同所致. EPR和HPP级分在低频区域的流变行为符合经典线性黏弹性理论, 为均相体系特征, 而EbP级分则出现"第二平台", 表现出非均相体系的特征. 对IPC中HPP/EPR共混物的流变行为的进一步研究发现, 当HPP/EPR质量比达到IPC中的比例时即可在低频区域产生"第二平台"; 当将EPR的比例增加至EPR和EbP组分之和时, EPR产生的平台要比IPC更为明显, 表明IPC中HPP与EPR存在的相分离足以使IPC产生"第二平台"现象.

关键词: 抗冲共聚聚丙烯, 动态流变行为, 线性黏弹性

Abstract: The dynamic rheological behavior of the melts for an impact propylene copolymer(IPC) and its three fractions were examined. The results show that the dynamic storage modulus(G') of IPC exhibits "pseudo solid-like" behavior at low frequency(ω), i.e. a "second plateau" appears in the lgG' vs. lgω plotting. This phenomenon indicates that the IPC melt is endowed with a characteristic of heterogeneous phase. The differences in G' and complex viscosity(η*) among the fractions of IPC appear dramatic, which are probably induced by the differences of the molecular weight and the length of the molecular chains among the fractions. The dynamic rheological behavior of the EPR and HPP fractions well accord with the linear viscoelasticity, implying that these fractions are homogeneous system. Moreover, the dynamic rheological behavior of the EbP exhibits "pseudo solid-like" behavior at low ω, meaning that this fraction is a heterogeneous system. On the other hand, the "second plateau" can be observed in low ω region for the HPP/EPR blends when the proportion of the EPR is the same as the proportion of EPR in IPC, suggesting that the "second plateau" in IPC results from the phase-separation between HPP and EPR, and the existence of EbP does not play a key role in the generation of "second plateau" in IPC.

Key words: Impact polypropylene copolymer, Dynamic rheological behavior, Linear viscoelasticity

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