应用化学

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聚乙烯-g-聚苯乙烯对线性低密度聚乙烯/聚苯乙烯共混物机械性能和发泡行为的影响

张光春ab,邱健a,邢海平a*(),唐涛a*()   

  1. a 中国科学院长春应用化学研究所,高分子物理与化学国家重点实验室 长春 130022
    b 中国科学院大学 北京 100049
  • 收稿日期:2016-04-12 出版日期:2016-06-30 发布日期:2016-06-30
  • 通讯作者: 邢海平,唐涛
  • 基金资助:
    国家自然科学基金(51233005) 项目

Influence of Polyethylene-g-polystyrene on the Mechanical Properties and Foaming Behavior of Linear Low Density Polyethylene/Polystyrene Blends

ZHANG Guangchunab,QIU Jiana,XING Haipinga*(),TANG Taoa*()   

  1. a State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China
    b University of Chinese Academy of Sciences,Beijing 100049,China
  • Received:2016-04-12 Published:2016-06-30 Online:2016-06-30
  • Contact: XING Haiping,TANG Tao
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.51233005)

摘要:

以通过开环易位聚合、加氢反应和原子转移自由基聚合技术结合制备的聚乙烯-g-聚苯乙烯(PE-g-PS)作为增容剂,研究了加入不同PS支链长度的PE-g-PS对于线性低密度聚乙烯/聚苯乙烯(LLDPE/PS)共混物的机械性能和发泡行为的影响。 以典型组成m(LLDPE):m(PS)=70:30共混物为例,考察了PE-g-PS对共混物拉伸性能的影响。 相对于二元共混物,增容剂的加入使得断裂伸长率、拉伸强度和屈服强度皆提高,且含长PS支链的增容体系提高更明显。 采用超临界CO2釜式发泡工艺,考察了PE-g-PS中PS支链长度对共混物发泡行为的影响。 结果表明,相对于短PS支链体系,加入PE-g-PS1.59k(PS相对分子质量为1590)后的泡孔结构更加均一,完全没有“缝隙”形貌的出现。 当发泡温度降至80 ℃时,即使存在LLDPE发泡空间限制作用(LLDPE无法发泡),加入支链长度更长的PE-g-PS1.59k后泡孔分布也更加均一。

关键词: 线性低密度聚乙烯/聚苯乙烯共混物, 增容剂, 机械性能, 釜式发泡, 支链长度

Abstract:

Polyethylene-g-polystyrene(PE-g-PS) copolymers, which were synthesized by the combination of ring-opening metathesis polymerization(ROMP), hydrogenation and atom transfer radical polymerization(ATRP) method, were utilized to compatibilize linear low density polyethylene/polystyrene(LLDPE/PS) blends. Using the LLDPE/PS blend in mass ratio of 70:30 as example, the effect of introduction of PE-g-PS on the mechanical properties was investigated. Compared to binary blends, elongation at break, tensile strength and yield strength are improved when the PE-g-PS is introduced. Utilizing PE-g-PS0.34k(the subscript 0.34k represents a relative molecular mass of PS is 340) and PE-g-PS1.59k as compatibilizers, the influence of PS branch length on foaming behavior of LLDPE/PS blends was investigated in a batch foaming process with supercritical carbon dioxide as physical foaming agent. Compared to the case containing PE-g-PS0.34k, the cellular structure of the foamed blends becomes much more uniform and no large gap appeares with the addition of PE-g-PS1.59k. When the foaming temperature is lowered to 80 ℃, confined effect of LLDPE solid around exists, much more uniform cellular structure also appears as PE-g-PS1.59k is introduced.

Key words: linear low density polyethylene/polystyrene blends, compatibilizer, mechanical properties, batch foaming, branch length