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

研究了高氧化态过渡金属盐(CuX2/L、FeX3/L,X=C1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...

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

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.