高等学校化学学报 ›› 1997, Vol. 18 ›› Issue (2): 317.

• 论文 • 上一篇    下一篇

低密度聚乙烯光交联点的结构及其形成机理

瞿保钧, 徐云华, 瞿欣   

  1. 中国科学技术大学结构分析开放研究实验室, 合肥, 230026
  • 收稿日期:1996-01-22 出版日期:1997-02-24 发布日期:1997-02-24
  • 通讯作者: 瞿保钧, 男, 52岁, 博士, 教授.
  • 作者简介:瞿保钧, 男, 52岁, 博士, 教授.
  • 基金资助:

    国家自然科学基金;国家教育委员会留学归国人员基金

Photoinitiated Crosslink Structures and Mechanisms of Low Density Polyethylene

QU Bao-Jun, XU Yun-Hua, QU Xin   

  1. Structure Research Laboratory, University of Science and Technology of China, Hefei, 230026
  • Received:1996-01-22 Online:1997-02-24 Published:1997-02-24

摘要: 用溶液高分辨核磁共振和荧光光谱等方法研究了由光引发剂二苯甲酮(BP)引发低密度聚乙烯(LDPE)和模型化合物交联点的结构、BP的光解产物及其形成机理.首次观测和鉴定了光交联LDPE(XLPE)中的H型和Y型长链支化交联点;据估计在熔融态紫外光照5~1O的XLPE样品中H型和Y型文联点的产率分别为5.7~16.9和7.6~21.6个结构单元.确定了BP在光引发过程中光解的主要产物为苯并哪醇,并探讨了存在少量α,α'一二本基烷醇的可能性.

关键词: 低密度聚乙烯, 二苯甲酮, 交联点结构, 光解产物, 光交联机理

Abstract: Crosslink structures, photolytic products of benzophenone(BP) as a photoinitiator and their formation mechanisms in BP-photoinitiated crosslinking of low density polyethylene (LDPE) and its model compounds have been studled by solution state high resolution13C NMRand fluorescence spectroscopy etc..Both H-links and Y--type long branches in the photocrosslinked LDPE (XLPE) have been ohserved and identified for the first time.The concentrations of H- and Y-type crosslinks are estimated to be 5.7~16.9 and 7.6~21.6 structure units per 10000 carbon atoms with the XLPEsamples UV-irracliated for 5~10 seconds in the melt, respectively.The main photolytic product of BPidentified is benzopinacol.There are indications that a small amount of a-alkylbenzhydrols are also possibly formed by the reactions of ketyl radicals with alkyl radicals.

Key words: Low density polyethylene (LDPE), Benzophenone, Crosslink structure, Photolytic products, Photocrosslinking mechanism

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