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利用改进的双乳液溶剂挥发法制备了多孔聚乳酸(PLA)微球.通过采用具有不同沸点和水溶性的有机溶剂制备得到不同多孔结构的PLA微球.结果发现以二氯甲烷、氯仿和甲苯为溶剂制备的微球具有相似的均匀多孔结构,而以乙酸乙酯制备的微球却具有中空结构和多孔的壳层.通过进一步的实验研究了溶剂种类对于微球多孔结构的影响.结果表明溶剂的移出速率对于微球的多孔结构起到决定作用.最后在以上实验基础上探讨了以不同溶剂制备多孔微球的形成机理.
Porous polylactic acid (PLA) microspheres were prepared by the improved double emulsion solvent evaporation method. PLA microspheres with different porous structures were prepared by using organic solvents with different boiling points and water-solubility. The results showed that the PLA microspheres with methylene chloride, chloroform and toluene The microspheres prepared for the solvent have a similar uniform porous structure, while the microspheres prepared with the ethyl acetate have a hollow structure and a porous shell. The effect of the solvent species on the microstructure of the microspheres was further studied. The removal rate of the solvent plays a decisive role in the microstructure of porous microspheres.Finally, based on the above experiments, the formation mechanism of porous microspheres with different solvents was discussed.