高等学校化学学报 ›› 2012, Vol. 33 ›› Issue (05): 1116.doi: 10.3969/j.issn.0251-0790.2012.05.046

• 高分子化学 • 上一篇    

分子量多分散性对AB二嵌段共聚物相行为的影响

姚卫国, 周红梅, 窦艳丽, 赵雪, 侯琳   

  1. 吉林大学材料科学与工程学院, 教育部汽车材料重点实验室, 长春 130025
  • 收稿日期:2011-05-04 出版日期:2012-05-10 发布日期:2012-05-10
  • 作者简介:姚卫国, 男, 博士, 讲师, 主要从事高分子物理和化学研究. E-mail: wgyao@jlu.edu.cn
  • 基金资助:

    国家自然科学基金(批准号: 91123029, 61077066, 50902128)资助.

Polydispersity Effect on Phase Behavior of Diblock Copolymer

YAO Wei-Guo, ZHOU Hong-Mei, DOU Yan-Li, ZHAO Xue, HOU Lin   

  1. Key Laboratory of Automobile Materials, Ministry of Education, College of Materials Science and Engineering, Jilin University, Changchun 130025, China
  • Received:2011-05-04 Online:2012-05-10 Published:2012-05-10

摘要: 采用Monte Carlo方法研究了分子量多分散性对AB型嵌段共聚物相行为的影响. 通过调整嵌段共聚物中组分含量, 考察了整体多分散性和单嵌段多分散性对嵌段共聚物共混物的有序-无序转变(Order-disorder transition, ODT)、 形貌及链尺寸的影响. 研究结果表明, 多分散度的增大使无序相向较大χN区域略微移动, 形成的片层结构厚度增加. 在形成微观有序形貌后, 较大分散度时各亚组分的链会得到更大的伸展, 表明分子链堆积受挫的程度减小, 因此, 涨落作用受到的抑制作用减小, 无序相区向更低温度区域移动.

关键词: Monte Carlo模拟, 分子量多分散性, AB二嵌段共聚物, 相行为

Abstract: Effect of polydispersity on phase behavior of diblock copolymer was studied by Monte Carlo simulation. In order to evaluate the polydispersity effect, block copolymer blends including three different components were utilized as models in the simulation. By controlling the weight fractions of the component in copolymer blend, the influence of two different types of polydispersity effects (i.e. overall polydispersity effect and single block polydispersity effect, respectively) on order-disorder transition(ODT), conformations, and chain size of polymers were investigated. The results show that the increasing of index of polydispersity(PDI) can cause the ODT temperature slightly shifts to a lower temperature region. And it can also induce the increasing of the spacing thickness of the newly formed lamellar structure. Based on microscopic conformation analysis, polymer chains tend to stretch more at larger PDIs, which reveals the decreasing of accumulation degree of polymer chains. Therefore, the inhibition effect on fluctuation diminishes and the disordered phase shifts to the lower temperature region.

Key words: Monte Carlo simulation, Polydispersity effect, Diblock copolymer, Phase behavior

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