高等学校化学学报 ›› 2018, Vol. 39 ›› Issue (3): 558-565.doi: 10.7503/cjcu20170602

• 高分子化学 • 上一篇    下一篇

苯乙烯单体对不同分子形态聚乙烯的扩散聚合行为

黄承焕, 陈韵乐, 郭朝霞(), 于建()   

  1. 清华大学化工系, 先进材料教育部重点实验室, 北京 100084
  • 收稿日期:2017-09-06 出版日期:2018-03-10 发布日期:2017-12-13
  • 作者简介:联系人简介: 郭朝霞, 女, 博士, 副教授, 博士生导师, 主要从事高分子复合材料及纳米纤维研究. E-mail:guozx@mail.tsinghua.edu.cn;于 建, 男, 博士, 教授, 博士生导师, 主要从事高分子合金及高分子复合材料研究. E-mail:yujian03@mail.tsinghua.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 51173095)资助

Diffusion and Polymerization Behavior of Styrene in Polyethylene Pellets of Different Molecular Structures

HUANG Chenghuan, TAN Yinle, GUO Zhaoxia*(), YU Jian*()   

  1. Key Laboratory of Advanced Materials, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
  • Received:2017-09-06 Online:2018-03-10 Published:2017-12-13
  • Contact: GUO Zhaoxia,YU Jian E-mail:guozx@mail.tsinghua.edu.cn;yujian03@mail.tsinghua.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.51173095)

摘要:

采用苯乙烯(St)单体对具有不同分子形态的聚乙烯(PE)进行了扩散聚合行为研究. 结果表明, 与高密度聚乙烯(HDPE)和线性低密度聚乙烯(LLDPE)相比, 由于低密度聚乙烯(LDPE)中长支链的存在导致其结晶度最低, 因此LDPE能够为St单体扩散提供更多的自由体积, 故St单体的扩散速率最快, 聚苯乙烯(PS)扩散饱和值最高. PS在不同种类的PE颗粒中均呈现为“M”型分布, 且在不同PE颗粒中PS纳米微球粒径基本相同. 部分扩散到PE颗粒内部的St会对PE接枝形成PE-g-PS, 这种接枝物在相界面处可作为相容剂减小分散相的尺寸, 增加分散相和基体间的界面黏合力, 同时可使材料的拉伸强度和杨氏模量得到明显提高.

关键词: 聚乙烯, 苯乙烯, 结晶度, 扩散, 聚合

Abstract:

Diffusion and polymerization behavior of styrene(St) in polyethylene(PE) of different molecular structures were studied. The results show that low density polyethylene(LDPE) could provide more free volume for the diffusion of styrene than high density polyethylene(HDPE) and linear low density polyethylene(LLDPE) because of its lowest crystallinity. Therefore, the diffusion rate of styrene in LDPE pellets is the fastest, and the maximum amount of styrene diffusion is also the highest. Polystyrene(PS) has a distinct distribution of “M” type in different PE pellets and the size of PS nanoparticles is almost indentical. PE-g-PS at the interface, generated by chemical grafting of styrene onto PE molecules, can act as compatibilizer, reducing the size of the dispersed phase and increasing the interfacial adhesion between the dispersed phase and the matrix, and therefore the tensile strength and Young’s modulus are significantly improved.

Key words: Polyethylene, Styrene, Crystallinity, Diffusion, Polymerization

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