2,2-二氢过氧丁烷与环烷酸钴对苯乙烯/富马酸二乙酯的引发机理

摘要

以4-苄氧基-2,2,6,6-四甲基-1-哌啶氮氧自由基(T)为捕捉剂,利用自由基捕捉技术和高分辨液相-电喷雾电离质谱联用(HPLC-ESI/MS)技术,研究了工业用过氧化甲乙酮溶液(MEKP)中的单倍体2,2-二氢过氧丁烷(俗称T4)在环烷酸钴的催化作用下对苯乙烯/富马酸二乙酯共聚时的竞争引发机理。依据实验结果,提出了T4-钴离子引发苯乙烯/富马酸二乙酯共聚的机理。T4在金属钴催化作用下分解产生烷氧自由基,该自由基极不稳定,主要通过β-断裂产生乙基和过氧乙酸。不稳定的过氧酸会继续分解产生酰氧自由基和羟基,酰氧自由基进一步分解产生甲基或乙基,由此生成的乙基、甲基和羟基是引发单体聚合的真正引发源。对于苯乙烯/富马酸二乙酯的竞争引发反应,乙基易于加成富马酸二乙酯,甲基易于加成苯乙烯,而羟基只能引发苯乙烯。同时,这些高活性自由基也存在着显著的氢提取过程。

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	黄一烽
	王聪彩
	张建华
	郭睿威

关键词： MEKP引发机理；自由基捕捉技术；竞争引发

Abstract：

The initiation and competitive polymerization mechanism of 2, 2-dihydroperoxybutane (T4) accelerated by cobalt naphthenate to initiate styrene/diethyl fumarate was studied by radical trapping method and high pressure liquid chromatogram-electrospray ionization-mass spectrometry (HPLC-ESI/MS) with 4-benzyloxy-2, 2, 6, 6-tetramethyl-1-piperidinyloxy (T) as scavenger. The reaction pathways of T4-cobalt initiated polymerization were proposed based on this experiment. T4 can be accelerated by cobalt ion to generate alkoxyl radical, which majorly undergo β-scission to form ethyl radical and peroxyacetic acid, while peroxyacetic acid can decompose to produce methyl and hydroxyl radical. The generated methyl, ethyl, ethyl oxygen and hydroxyl radicals are the major source of initiating styrene and diethyl fumarate. As for the competitive initiation to styrene and diethyl fumarate, ethyl radical is more prone to initiate diethyl fumarate, methyl radical is easier to initiate styrene, and hydroxyl radical can only initiate styrene. Besides, there exists hydrogen abstraction and transfer in these highly active radicals.

Keywords： initiation mechanism of MEKP； radical trapping method； competitive initiation

Received 2014-04-11;

Corresponding Authors: 郭睿威,E-mail:rwguo@263.net。 Email: rwguo@263.net

About author: 黄一烽(1988-),男,硕士研究生,从事不饱和聚酯固化机理的研究。

引用本文:

黄一烽, 王聪彩, 张建华, 郭睿威.2,2-二氢过氧丁烷与环烷酸钴对苯乙烯/富马酸二乙酯的引发机理[J]. 化学工业与工程, 2016,33(3): 25-30

Huang Yifeng, Wang Congcai, Zhang Jianhua, Guo Ruiwei.Initiation Mechanism of 2, 2-Dihydroperoxybutane Accelerated by Cobalt Naphthenate to Initiate Styrene/Diethyl Fumarate[J]. Chemcial Industry and Engineering, 2016,33(3): 25-30

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