淀粉／甲基丙烯酸甲酯接枝共聚及生物降解性能研究

STUDIES ON GRAFTNG COPOLYMERIZATION OF METHYL METHACRYLATE ONTO CORN STARCH AND BIODEGRADABILITY OF COPOLYMER

本文以硝酸铈铵为引发剂，研究了单体浓度、引发剂用量、反应温度和反应时间对淀粉与甲基丙烯酸甲酯（ＭＭＡ）接枝共聚反应特征参数的影响。当引发剂浓度为４．５×１０（－３）Ｍ／Ｌ，ＭＭＡ浓度为０．２２５Ｍ／Ｌ，在３０℃反应３．５ｈ时，单体转化率Ｃ％＝９０．５％，接枝率Ｇ％＝６２％，接枝效率ＧＥ％＝７０％，接枝支链的粘均分子量Ｍ＝×１０（－３）。接枝共聚物及其与聚氯乙烯（ＰＶＣ）共混物浇铸成膜后，用黑曲霉在无机盐营养培养基中降解４０天，失重率分别为３２％和２３％，表明淀粉／ＭＭＡ接枝共聚物可作为生物降解塑料使用。

Graft copolymer of corn starch and methyl methacrylate(MMA) was synthesed with ceric ammonium nitrate as initiator.The effect of monomer concentration,initiator concentration, reaction temperature and reaction time on monomer conversion (C%), grafting efficiency(GE%)and grafting(G%) has been also studied. The C%, GE% and G% approached the maximum of 90% ,70% and 62% as the monomer concentration and initiator concentration were raised to 0. 225 M·L(-1)and 4. 5×10(-3)M·L(-1) at 30℃ for 3.5 h respectively.The graft copolymer and its blending product with polyethylene chloride(PVC) show excellent susceptibility to fungal growth.Graft copolymer sample losing more than 32% of its weight after 40 day of incubation with Aspergillus niger and the blending product sample losing 2 3%. The result of biodegradation show that the copolymer and the blending may have application as a biodegradable plastic.