壳聚糖与L-丙交酯接枝共聚物的均相和非均相合成

Synthesis of Homogeneous and Heterogeneous Graft Copolymer of Chitosan and Lactide

以1-丁基-3-甲基咪唑氯盐([BMIM]Cl)、1-丁基-3-甲基咪唑醋酸盐([BMIM]Ac)为均相介质,以二甲基亚砜为非均相介质,研究了L-丙交酯与壳聚糖接枝共聚物的合成,并考察其接枝反应的反应效率,利用红外光谱(FT-IR)、热重分析(TGA)、差示扫描量热仪(DSC)、X射线衍射分析(XRD)等对接枝共聚物进行了表征。结果表明,均相反应能缩短反应时间,具有更高的反应效率,且在[BMIM]Cl中更高;均相接枝共聚物趋于无定型,但其热稳定性高于非均相接枝共聚物。

The homogeneous and heterogeneous graft copolymerization of L-lactide（L-LA） onto chitosan（CS） using ionic liquids： 1-butyl-3-methylimidazolium chloride（Cl）,1-butyl-3-methy-limidazolium acetate（Ac） and dimethyl sulfoxide（DMSO） as reaction medium were studied.The graft reaction efficiencies in different media were compared and the obtained chitosan grafted poly（L-lactide） was characterized by Fourier transform infrared spectrum（FT-IR）,thermogravimetric analysis（TGA）,differential scanning calorimetry（DSC） and X-ray diffraction（XRD）.The results show that the reaction efficiency of homogeneous graft copolymerization is higher than that of heterogeneous,and as to the homogeneous reactions of two kinds of ionic liquids,the reaction efficiency of Cl is higher than of Ac.Thermal stability of homogeneous graft copolymer is higher than of the graft copolymer in dimethyl sulfoxide（DMSO）.The homogeneous graft copolymer tends to amorphous and the heterogeneous graft copolymerization of chitosan is only partly destroyed.