通过自乳化的方法合成了具有聚己内酯-聚乙二醇-聚已内酯嵌段结构的聚氨酯水溶液,再采用凝聚相分离法合成了一种新型的聚氨酯微球。研究了聚乙二醇分子量、异氰酸基与羟基的摩尔比、聚己内酯与聚乙二醇的摩尔比、预聚温度、聚氨酯水溶液浓度、CaCl2浓度和搅拌速度等条件对聚氨酯微球的影响,以及傅立叶变换红外光谱(FTIR)和扫描电子显微镜(SEM)表征了微球的化学结构和表面形态结构。通过对合成条件的优化,找出了合成稳定、均匀和形态好的聚氨酯微球的最佳条件。实验结果表明,制备的聚氨酯微球平均粒径2mm左右,分布相对均匀,球形较好。
Polyurethane(PU) water solutions with the block structure of PCL-PEG-PCL were synthesized by the self-emulsification method. And PU microspheres were prepared by the eoaeervation phase separation method. The influencing factors of PU microspheres were investigated including the molecular weight of polyethylene glycol (PEG), the mole ratio of the -NCO/-OH,the ratio of the PCL/PEG, prepolymerization temperature, the concentrations of PU water solution, the concentrations of CaCl2, and the emulsifying rate. The structure and surface morphology of the PU microspheres were measured by Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscope (SEM). The best conditions were found to synthesize the stable, mean and globose PU microspheres under the optimized condition. Experimental results showed the average diameter of the PU microspheres was about 2mm and the distribution of spherical PU microspheres was relatively uniform.