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使甲基丙烯酸单封端聚乙二醇大分子单体(MA-PEG)与甲基丙烯酸甲酯(MMA)在N,N-二甲基甲酰胺(DMF)中进行自由基接枝共聚反应,得到了以PEG为支链,聚甲基丙烯酸甲酯为主链(PMMA-g-PEG)的接枝共聚物。用核磁共振(1H-NMR),傅立叶红外光谱(FTIR)和凝胶渗透色谱(GPC)对PMMA-g-PEG的结构与相对分子量进行了表征。结果表明,所合成的共聚物结构明确,在MA-PEG大分子单体与MMA的不同配比条件下,得到的PMMA-g-PEG的分子量和分子量分布基本相同。并通过差示扫描量热仪(DSC)研究了接枝共聚物的热力学性质,结果表明,PMMA-g-PEG具有明显的相转变,其相变焓、相变温度与PEG的含量有关,并且随其含量的增加而增大。
Free radical graft copolymerization of methacrylic acid mono-capped polyethylene glycol macromonomer (MA-PEG) and methyl methacrylate (MMA) in N, N-dimethylformamide , A graft copolymer with PEG as the main chain and polymethylmethacrylate as the main chain (PMMA-g-PEG) was obtained. The structure and relative molecular weight of PMMA-g-PEG were characterized by 1H-NMR, FTIR and GPC. The results showed that the structure of the synthesized copolymer was clear. The molecular weight and molecular weight distribution of the obtained PMMA-g-PEG were basically the same under the different ratio of MA-PEG macromonomer and MMA. The thermodynamic properties of the grafted copolymer were studied by differential scanning calorimetry (DSC). The results showed that PMMA-g-PEG had obvious phase transition, the enthalpy of phase transition and the phase transition temperature were related to the content of PEG. With its content increases.