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研究了高氧化态过渡金属盐(CuX2/L、FeX3/L,X=Cl或Br;L=2,2’-联吡啶、N,N’-四甲基乙二胺、N,N,N’,N″,N″-五甲基二亚乙基三胺;CuSO4)催化甲基丙烯酸2-(N,N-二乙氨基)乙酯(DEAEMA)的自引发氧化聚合,利用气相色谱跟踪单体转化率、利用凝胶渗透色谱和多角激光光散射跟踪聚合物分子量在聚合过程中的变化.结果显示,不加入任何引发剂,高氧化态过渡金属盐可在30～60℃范围内催化DEAEMA的自引发氧化聚合,且随着反应的进行,所得聚合物的分子量随转化率的增大而缓慢上升,且分子量呈现宽分布.多角激光光散射的结果则显示即使低转化率时所得PDEAEMA的绝对分子量也已呈现少见的多峰分布,并且低分子量组分的含量随聚合的进行逐渐减少.通过与CuSO4催化小分子叔胺氧化还原引发能力的比较可知,DEAEMA在高氧化态过渡金属盐的催化下起到自身还原性引发型单体的作用,高氧化态过渡金属盐通过氧化还原将DEAEMA的二乙基氨基α位C—H键氧化成Cα.自由基,引发DEAEMA的普通自由基聚合,形成线型PDEAEMA初级链.随后高氧化态过渡金属盐与PDEAEMA构成氧化还原体系,引发DEAEMA聚合,最终得到具有一定数量侧链的高分子量支化PDEAEMA.以上结果表明,自身还原性引发型单体可通过“一锅煮”式普通自由基聚合制备长链支化聚合物.
The effects of high oxidation state transition metal salts (CuX2 / L, FeX3 / L, X = Cl or Br; L = 2,2’-bipyridine, N, N’-tetramethylethylenediamine, (N, N’-pentamethyldiethylenetriamine; CuSO4) catalyzed the self-initiated oxidative polymerization of 2- (N, N-diethylamino) ethyl methacrylate (DEAEMA) The monomer conversion, the change of the molecular weight of the polymer during the polymerization were measured by gel permeation chromatography and polygonal laser light scattering. The results showed that without any initiator, high oxidation state transition metal salts can be catalyzed in the range of 30 ~ 60 ℃ DEAEMA self-initiated oxidative polymerization, and as the reaction progresses, the molecular weight of the resulting polymer increases slowly with increasing conversion, and the molecular weight exhibits a wide distribution.The results of polygonal laser light scattering show that even at low conversion, the obtained PDEAEMA Of the absolute molecular weight has also shown a rare multimodal distribution, and the content of low molecular weight components gradually decreases with the polymerization.CuSO4 catalytic small molecule tertiary amine redox initiating capacity comparison shows that DEAEMA in high oxidation state transition metal salt Catalytic play the role of self-reducing initiating monomer, high oxidation state The metal salt oxidizes the C-H bond at the α-position of the diethylamino group of DEAEMA to the Cα radical by redox reaction, initiating ordinary radical polymerization of DEAEMA to form a linear PDEAEMA primary chain, followed by the formation of the PDOEMA transition metal salt Redox system, triggering the polymerization of DEAEMA, and finally get a certain number of side chains of high molecular weight branched PDEAEMA The above results show that the self-reducing initiating monomer can be One-pot ordinary free radical polymerization of long chain branching polymer.