改性淀粉/聚氨酯复合微球的合成与性能研究

Research on synthesis and performance of the modified starch/polyurethane complex microspheres

采用超声改性法制备改性淀粉,通过预聚-扩链-中和-分散法合成聚氨酯水溶液,并用相分离法制备出超声改性淀粉/聚氨酯复合微球。考察了R值[n(—NCO)/n(—OH)]、改性淀粉的含量、聚乙二醇的分子量及固含量对复合微球形态的影响。研究了载药复合微球在体外的药物释放规律。并通过扫描电子显微镜和傅里叶变换红外光谱对微球的表面及剖面结构和化学组成进行了表征。结果表明:复合微球合成的最佳条件:R值为3,改性淀粉含量为6%(wt,质量分数,下同),聚乙二醇分子量为200,固含量为38%;复合微球表面光滑并且内部有很多致密的孔道,且聚氨酯和改性淀粉之间通过氢键连接,稳定性良好;降解性及药物释放研究显示,该类微球适于充当药物载体。

On the basis of adopting the ultrasonic modification method to prepare modified starch,and the chain extender,neutralization as well as dispersion method were performed for synthesis of polyurethane aqueous solution,at end ultrasonic modified ST/PU composite microspheres were prepared by the condensed phase separation method.The impacts of the n（—NCO）/n（—OH）,mass fraction of starch molecular and weight of polyethylene glycol,and solid content of the composite material on the morphology of microspheres were investigated.The drug release regularity of microspheres as drug carrier in vitro was explored.And the surface structure and chemical composition of microspheres were characterized through the scanning electron microscope（SEM）and fourier transform infrared spectroscopy（FT-IR）.Results showed that the optimum condition for synthesis of composite microspheres：Rvalue of 3,modified ST contentat 6%,the molecular weight of PEG 200,solid content was 38%.Microspheres had smooth surface externally and a great number of dense tubular pores internally,which were suitable to be drug release carrier.FT-IR illustrated that PU and ST were connected through hydrogen bond,which made composite microspheres had good stability.