波谱学杂志 ›› 1990, Vol. 7 ›› Issue (4): 359-365.

• 研究论文 •    下一篇

低密度聚乙烯光引发交联机理——I.ND自旋捕捉ESR研究

瞿保钧1, 徐云华1, 施文芳1, 徐广智2   

  1. 1. 中国科技大学, 合肥;
    2. 中国科学院化学研究所, 北京
  • 收稿日期:1989-06-20 修回日期:1990-01-17 出版日期:1990-12-05 发布日期:2018-01-23
  • 基金资助:
    国家自然科学基金会;中国科技大学结构研究实验室的资助项目

MECHANISM OF PHOTOINTTIATED CROSSLINKING OF LOW DENSITY POLYETHYLENE——I. ND SPIN-TRAPPING ESR STUDY

Qu Baojun1, Xu Yunhua1, Shi Wenfang1, Xu Guangzhi2   

  1. 1. University of Science & Technology of China, Hefei;
    2. Institute of Chemistry, Acadtmia Sinica, Beijing
  • Received:1989-06-20 Revised:1990-01-17 Online:1990-12-05 Published:2018-01-23

摘要: 本文使用2,3,5,6——四甲基亚硝基苯(ND)自旋捕捉ESR技术研究了由二苯甲酮(BP)光引发低密度聚乙烯(LDPE)交联自由基中间体。采用改变温度和熔融态检测到分辨得很好的氮氧自旋加合物自由基ESR谱的方法,鉴定了光引发LDPE交联前躯自由基主要为仲碳自由基,-CH2-?H-CH2-和叔碳自由基,。由此可见,BP引发LDPE的光交联反应主要发生在仲碳和叔碳原子上。

关键词: 电子自旋共振, 自由基中间体, 自旋捕捉, 低密度聚乙烯, 紫外辐照

Abstract: The radical intermediates formed by photoinitiated crosslinking of low density polyethylene (LDPE) with benzophenone (BP) as photoinltiator have been investigated by spin-trapping ESR technique using 2,3,5,6-tetramethylnitrosodurene (ND). By the temperature change and determining the well-resolved ESR spectrum of the nitroxide spin-adducts at the melt, the following two radicals could be identified:one was the secondary carbon radical,CH2-?H-CH2-,another was the tertiary carbon radical,.Based on these results, the photocrosslinking reactions of LDPE initiated by BP mainly take place at the secondary and tertiary carbons.

Key words: Electron spin resonance, Radical intermediates, Spin trapping, Low density polyethylene, UV irradiation