甲基丙烯酸(N,N-二甲氨基)乙酯的自引发催化氧化聚合

Self-initiated catalytic oxdiative polymerization of 2-(N,N-dimethylamino) ethyl methacrylate

作为一种自身还原性单体,甲基丙烯酸(N,N-二甲氨基)乙酯(DMAEMA)可与部分氧化剂构成氧化还原引发剂体系,并引发自身的聚合.为验证该假设,进行了以CuCl2络合物催化DMAEMA的本体氧化聚合.动力学研究表明,所得聚合物的分子量随着聚合时间的延长而逐渐增加.核磁波谱分析表明,低转化率下所得低聚物同时含有甲基丙烯酸酯末端和C-Cl端基,显示DMAEMA的二甲氨基(N-CH3)被CuCl2氧化成单体自由基(N-CH2·),并通过原子转移自由基聚合(ATRP)机理形成聚合物.由于叔胺广泛地用作ATRP的络合物,由此可见,在传统ATRP体系中,来自CuCl2/叔胺的氧化还原引发不可忽略.

As an intrinsically reducing monomer,2-（N,N-dimethylamino） ethyl methacrylate（DMAEMA） was reported to be involved in redox initiation in the presence of proper oxidizing agents.In order to verify the postulate,the CuCl2/ligand-catalyzed oxidative polymerization of DMAEMA was carried out in bulk.The kinetic study showed that the molecular weight of the poly（DMAEMA） increased gradually with the reaction time.Nuclear magnetic resonance（NMR） spectroscopy implied that the oligo（DMAEMA） contained both a methacryloxyl and a C-Cl termini,confirming that the N-CH3 moiety of DMAEMA was oxidized into the N-CH2·radical by CuCl2,and that atom transfer radical polymerization（ATRP） mechanism partially resulted in the process.Taking the fact into account that tertiary amines are widely used in ATRP as ligands,it is clear that the CuCl2/tertiary amine redox initiation was significant to a certain extent.