乙酰化淀粉/DL-丙交酯接枝共聚物的合成及降解性能研究

用醋酸乙烯酯和玉米淀粉反应制备出了不同取代度乙酰化淀粉，再用乙酰化淀粉同DL－丙交酯接枝共聚合成乙酰化淀粉／DL－丙交酯接枝共聚物。研究了原料配比，淀粉取代度对接枝反应单体转化率（C％），接枝率（G％）接枝效率（GE％）和接枝支链数均分子量（Mn)的影响，结果表明在给定的试验条件下接枝共聚反应的C％，G％，GE％和Mn可分别达到40％，225％，80％和1．4万。接枝共聚物在磷酸缓冲溶液和户外土壤掩埋降解实验表明，在160天内样品失重率分别为71％和60％，表明合成的乙酰化淀粉／DL－丙交酯接枝共聚物具有很好的降解性能。

STUDIES ON GRAFTING COPOLYMERIZATION OF ACETYLATING STARCH /DL-LACTIDE AND BIODEGRADABILITY

The acetylating starch/DL-lactide grafting copolymer was synthesized in N,N dimethylacetamide (Me2NAC) in the presence of sodium bicarbonate. The effects of substitute degree of starch on monomer convention (C%), grafting (G%), grafting efficiency (GE%) and grafting side chain molecular weight have been studies. The C%, G% and GE% could approach 40%, 225% and 80% respectively while substitution degree of acetylating starch <0.4.The Fourier transform infrared (FTIR) spectroscopy was used to characterize the grafting side chain poly-DL-lactide. The FTIR spectrum shows an absorption band at 1750cm-1confirming the formation of ester bond, indicating the acetylating starch/DL-lactide grafting copolymer was synthesized. The degradability of grafting copolymer was tested with outdoor soil burial and in phosphorous buffer solution, the weight loss reached 60% and 71% respectively after 160 day for the copolymer, the result show the grafting copolymer has good biodegradability.