天冬氨酸与谷氨酸共聚反应研究

以天冬氨酸（A）和谷氨酸（G）为单体，在1,3,5-三甲苯（TB）和环丁砜（SUL）混合溶剂中，分别进行两者均聚及共聚反应，考察了溶剂配比、催化剂用量、单体配比、反应温度和时间等因素对产率、聚合物分子量和分子量分布的影响，并用FTIR和¹³C-NMR 对聚合产物进行了结构表征。结果表明，随着混合溶剂中TB含量增加、催化剂用量增加、反应温度升高和时间延长，产率和聚合物的分子量均增加。但催化剂用量过多和反应温度过高对聚合是不利的。天冬氨酸的反应活性大于谷氨酸，两者可以进行共聚反应，产率、共聚物的分子量及分子量分布随单体配料中A含量的增加而增大。不同A/G配比下得到产物的GPC谱图曲线为较窄的单峰分布，分子量分布指数（M_w/M_n，MWD）从1.34到1.87，数均分子量（M_n）范围从6000到11900。

The copolycondensation of L-aspartic acid and L-glutamic acid

The copolycondensation of L-aspartic acid(A) and L-glutamic acid(G) was conducted in sulpholane,1,3,5-trimethyl benzene or mixtures of these solvents.The effects of varying the dosage of the phosphoric acid catalyst,monomer ratios,solvent ratios,reaction temperature and time on yield,molecular weight and average molecular weight distribution((M)_w/(M)_n,MWD) of the polymer products were investigated.The yield and molecular weight were found to increase with increasing concentration of phosphoric acid,proportion of 1,3,5-trimethyl benzene in the mixed solvent,reaction temperature or time.L-aspartic acid is more reactive than L-glutamic acid and the molecular weight of the copolymer increases with increasing monomer ratio of A to G.The GPC traces of the copolymers of L-aspartic acid and L-glutamic acid(PAG) obtained with different monomer ratios exhibit unimodal narrow distributions with number-average molecular weight((M)_n) in the range of 6000 to 11900 and polydispersity in the range of 1.34 to 1.87.