高等学校化学学报 ›› 2006, Vol. 27 ›› Issue (2): 389.

• 研究论文 • 上一篇    下一篇

尼龙-6 18的晶型转变研究

肖丹, 崔晓文, 李卫华, 颜德岳   

  1. 上海交通大学化学化工学院,  上海 200240
  • 收稿日期:2004-12-17 出版日期:2006-02-10 发布日期:2006-02-10
  • 通讯作者: 颜德岳(1937年出生), 男, 教授, 博士生导师, 主要从事聚合物反应动力学、 高分子合成和高分子物理的研究. E-mail:dyyan@sjtu.edu.cn
  • 基金资助:

     国家自然科学基金(批准号: 20274024, 50233030)资助.

Investigation on the Crystalline Transition of Nylon-6 18

 XIAO Dan, CUI Xiao-Wen, LI Wei-Hua, YA De-Yue   

  1. School of Chemistry and Chemical Technology,  Shanghai Jiaotong University, Shanghai  200240,  China
  • Received:2004-12-17 Online:2006-02-10 Published:2006-02-10
  • Contact: YA De-Yue,E-mail:dyyan@sjtu.edu.cn

摘要:

以偶偶尼龙-6 18为例, 通过示差扫描量热分析(DSC), 广角X射线衍射(WAXD)与傅里叶变换红外光谱(FTIR)等方法研究了其Brill转变的过程, 探索了脂肪族聚酰胺的晶型转变的本质. X射线衍射结果表明, 随着温度的升高, 尼龙-6 18由三斜晶系转变为假六方晶型, 同时其DSC曲线上出现一个较宽的吸热峰. 红外光谱结果表明, 在其晶型转变过程中, 晶体内氢键强度逐渐减弱, 与酰胺键相连的C—C和C—N键发生扭曲. 酰胺基团之间的亚甲基链段的振动逐渐增强, 部分亚甲基单元由反式构象变成旁式构象, 最后整齐排列的亚甲基链段逐渐变得无序化.

关键词: Brill转变; 尼龙-6 18; 构象; 三斜晶型; 假六方晶型

Abstract:

The Brill transition of even\|even nylon-6 18 was investigated by using differential scanning calorimetry(DSC),  temperature-dependent wide angle X-ray diffraction(WAXD) and Fourier transform infrared(FTIR). The X-ray diffraction results indicate that the melt-crystallized sample of nylon-6 18 transforms from the triclinic unit cell to the pseudo-hexagonal phase in the  temperature range of 120—180  ℃. In this range,  the thermograph of nylon-6 18 presents a broad endothermal peak. From the FTIR spectra,  it can be found that,  during the transition process of nylon\|6 18,  the intensity of the intrasheet hydrogen bonds  becomes weak. At the same time,  the CH2-amide bonds twist and the all\|trans conformation of methylene sequences is disordered by inserting the gauche conformation. The CH2 segments are in a mobile state because of the enhanced stretching and twisting vibrations of  C—CO and C—N bonds.

Key words: Brill transition;  Nylon-6 18;  Conformation;  Triclinic crystalline model;  Pseudo-hexagonal crystalline model

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