中文摘要：

单一的壳聚糖降解太慢,且成膜性差,拟用聚乙二醇（PEG）对壳聚糖（CTS）进行共混改性。选用不同摩尔质量的聚乙二醇,用溶液浇铸法制备不同质量比的壳聚糖/聚乙二醇的共混物,用偏光显微镜、热分析等方法表征了共混物的热性能及聚集态的表征,定性分析了共混体系的相容性。当PEG的质量分数增加到25%时,可以在共混薄膜的偏光显微镜照片中看到明显的聚乙二醇球晶,随着PEG含量的增加,球晶颗粒更加明显,形态更为完整清晰。当CTS质量分数超过50%时,其DSC曲线可以观察到明显的玻璃化转变,随着PEG质量分数的增大,混合物的玻璃化转变温度逐渐降低;相同质量分数,含PEG1000共混物的熔融温度变化值小于含PEG800的共聚物。用溶液浇铸法在壳聚糖中引入的不同分子量的聚乙二醇,共混体系相容性好,实现了热力学水平上的均相。有效增强了共混物的亲水性,继而加快壳聚糖的降解速率。

英文摘要：

A single chitosan degradated slowly,and the film forming ability was poor,thus,the chitosan was mixed and modified by polyethylene glycol（PEG）.By using different molecular weight of PEG,chitosan/PEG blend in different weight ratio was prepared by solvent casting method.The thermal properties and aggregate state was characterized by means of polarizing microscope and TG,the compatibility of blends was analyzed qualitatively.When the PEG increased to 25 wt%,the PEG spherulite was apparent in the polarizing microscope graph of the blend film.Along with the increase of the content of PEG,the spherocrystal was more obvious and the form was clearer.When CTS exceeded 50 wt%,an obviously glass-transition can be observed by DSC,with the increasing of CTS content,the glass transition temperature in mixture gradually lowered.The changing value of melting temperature of the blend with PEG1000 was less than that of the blend with PEG800 with the same mass fraction.Introduced different molecular weight PEG in chitosan by solvent casting method,the blending system had good compatibility,reached homogeneous phase of the thermodynamic level.The hydrophilicity of the blend was effectively enhanced,and accelerated the degradation rate of chitosan.