大豆分离蛋白甲基丙烯酸接枝共聚物的合成与表征

Synthesis and Characterization of Graft Copolymers of Soybean Protein Isolate and Methacrylic Acid

以过硫酸铵为引发剂、2巯基乙醇为蛋白质变性剂,在浓度为8mol/L尿素溶液中进行了大豆分离蛋白与甲基丙烯酸的接枝共聚反应;傅里叶红外光谱和核磁共振谱证明,甲基丙烯酸成功地接枝到了大豆分离蛋白上;相关影响因素的单因数实验研究表明,各因数的最佳值分别为引发剂浓度16mmol/L,单体浓度2.4mol/L,反应温度80℃,反应时间4h,巯基乙醇浓度0.05mol/L。

The graft copolymers of soybean protein isolate (SPI) and methacrylic acid (MAA) had been prepared in 8mol/L urea aqueous solution under nitrogen atmosphere, using ammonium persulphate (APS) as an initiator, β-mercaptoethanol as a protein unfolding agent. Evidence of grafting was obtained by comparison of FTIR spectra and ~ ~13 C-NMR spectra of SPI and the grafted copolymers. The effects of APS, MAA, reaction temperature and reaction time on graft copolymerization were studied by determining the grafting parameters such as grafting percentage and grafting efficiency. The optimum reaction conditions of each effect were obtained as following: C_~APS  =16 mmol/L, C_~MAA =2.4mol/L, reaction temperature 80℃, reaction time 4h, C_~ME = 0.05mol/L.