高等学校化学学报

高等学校化学学报 ›› 2013, Vol. 34 ›› Issue (2): 485.doi: 10.7503/cjcu20120523

• 高分子化学 • 上一篇    

原位X射线研究拉伸过程中间规聚丙烯晶体熔融与晶体取向关系

邵春光1, 卓然然2, 李倩1, 曹伟1, 张阳1, 张瑞静1, 刘成刚1, 申长雨1   

  1. 1. 郑州大学国家橡塑模具工程研究中心, 力学与工程科学学院, 郑州 450002;
    2. 郑州大学物理工程学院, 郑州 450001
  • 收稿日期:2012-05-29 出版日期:2013-02-10 发布日期:2013-01-21
  • 通讯作者: 邵春光,男,博士,讲师,主要从事高分子材料加工过程中物理问题研究.E-mail:shaochunguang2008@yahoo.com.cn E-mail:shaochunguang2008@yahoo.com.cn
  • 基金资助:

    国家自然科学基金(批准号: 51103138, 11272291)和教育部高等学校博士点基金(批准号: 20094101110008)资助.

Relationship Between Crystal Orientation and Stress-induced Crystalline Melting of Syndiotactic Polypropylene Under Uniaxial Deformation via in situ Wide-angle X-ray Scattering

SHAO Chun-Guang1, ZHUO Ran-Ran2, LI Qian1, CAO Wei1, ZHANG Yang1, ZHANG Rui-Jing1, LIU Cheng-Gang1, SHEN Chang-Yu1   

  1. 1. Nation Engineering Research Center for Advanced Polymer Processing Technology, School of Mechanics and Engineering Science, Zhengzhou University, Zhengzhou 450002, China;
    2. Physical Engineering College, Zhengzhou University, Zhengzhou 450001, China
  • Received:2012-05-29 Online:2013-02-10 Published:2013-01-21

PDF (PC)

被引次数

9

摘要：

间规聚丙烯熔体(sPP)淬冷至液氮温度并保持5 min, 于20, 40, 80, 120 ℃下等温退火10 h, 制备出具有不同片晶厚度的样品. 在室温条件下, 利用原位X射线在线研究sPP样品拉伸过程中应力诱导的晶体熔融和晶体取向关系. 结果表明, 在单轴拉伸过程中, 应力导致的晶体熔融和晶体取向同时发生, 即两者在同一应变、 同一应力下同时发生, 这一特性不受片晶厚度的影响. 随着片晶厚度的增加, 晶体熔融和取向需要的临界应力不断增大, 在所研究范围内, 该临界应力的增加和片晶厚度基本呈线性关系. 另外, 随着片晶厚度增大, 样品的弹性模量、 屈服强度和应变硬化模量均有一定程度的增大.

关键词: 原位X射线衍射, 间规聚丙烯熔体, 晶体取向, 应力诱导晶体熔融, 片晶厚度

Abstract:

Melt of syndiotactic polypropylene(sPP) was quenched to liquid nitrogen and held for 5 min, then the quenched samples were put into vacuum oven at 20, 40, 80, 120 ℃ for 10 h to prepare samples with different lamellar thicknesses. Relationship between crystal orientation and stress-induced crystalline melting under uniaxial stretching was studied with the combination of micro-tensile tester and in-situ wide angle X-ray diffraction(WAXD) measurement. Based on these results, "stress-induced melting" always occurs simulta-neously with crystal orientation in spite of different lamellar thicknesses. Critical stress for stress-induced melting illustrated a linear correlation vs. lamellar thicknesses. Furthermore, with the increase of lamellar thickness, the mechanical properties of sPP samples, such as elastic modulus, yield stress and modulus of strain harden changed obviously.

Key words: In situ X-ray diffraction, Syndiotactic polypropylene, Crystal orientation, Stress-induced melting, Lamellar thickness

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