过渡金属盐催化甲基丙烯酸2-(N,N-二乙氨基)乙酯的自引发自由基聚合  

SELF-INITIATED OXIDATIVE RADICAL POLYMERIZATION OF 2-(N,N-DIETHYLAMINO)ETHYL METHACRYLATE CATALYZED WITH TRANSITION METAL SALTS

作　　者：宋瑾[1] 倪健[1] 蒋必彪[1] 陈建海[1] 翟光群[1] 

机构地区：[1]常州大学材料科学与工程学院,常州213164

出　　处：《高分子学报》2011年第12期1445-1453,共9页Acta Polymerica Sinica

摘　　要：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.Oxidative polymerizations of 2-（N,N-diethylamino）ethyl methacrylate（DEAEMA） as an intrinsically reducing inimer catalyzed by high-oxidation state transition metals（CuX2/ligand,FeX3/ligand,X=Cl or Br,ligand=2,2′-bipyridine,tetramethylethylenediamine,pentamethyldiethylenetriamine,CuSO4） were systematically investigated using gas chromatography,gel-peameation chromatography and multi-angle laser light scattering（MALLS） to monitor the monomer conversion,molecular weight（MW） and its distribution（MWD） of the PDEAEMA,respectively.The results showed that the high-oxidation state transition metals can steadily catalyze the free radical polymerization of DEAEMA with the reaction temperature ranging from 30℃ to 60℃ even in the absence of any chemical initiators,the MW of the PDEAMEA increased gradually with the conversion,while it maintained a rather broad MWD even from low conversions.The MALLS results showed that the absolute MW of the PDEAEMA showed an unusual multi-modal distribution.By comparing the CuSO4-catalyzed redox-initiation ability of lower-MW tertiary amines,it can be concluced that DEAEMA functions as an intrinsically reducing inimer under the catalysis of high-oxidation state transition metals,which oxidize the alpha C—H（Cα-H） of the amine group of DEAEMA into the Cα· radicals,initiating the conventional radical polymerization of DEAEMA and giving rise to linear PDEAEMA primary chains.Subsequently,the linear PDEAEMA chains serve as macro-initiators with high-oxidation state transition metals and initiate the graft polymerization of DEAEMA,leading to branched PDEAEMA with a certain number of side chains.It was inferred that self-initiated free radical polymerization of intrinsically reducing inimers under catalysis of high-oxidation state transition metals can produce long-chain-branched polymer via such a one-pot approach.

关 键 词：甲基丙烯酸2-(N N-二乙氨基)乙酯 自身还原性引发型单体 催化氧化聚合 氧化还原引发 

分 类 号：O631.5[理学—高分子化学]