【摘要】 以低相对分子质量生物可降解D,L 聚乳酸 (D,L PLA)二醇和六亚甲基二异氰酸酯 (HDI)为原料、1, 4 丁二醇(BD)为扩链剂及聚乙烯基吡咯烷酮(PVP)为悬浮剂,通过悬浮聚合法初步合成了一种新型聚氨酯微球(PUMS)。用扫描电子显微镜(SEM)考察了BD的含量对微球表面形态的影响,通过激光粒度分析仪讨论了搅拌速率和PVP浓度对微球粒径及其分布的影响,用傅立叶变换红外光谱(FTIR)粒度分析仪对微球的化学结构进行了表征。结果表明,合成的微球的平均粒径随搅拌速率和PVP浓度的增加而减少,粒径分布变宽;当搅拌速率为 400r/min,PVP质量分数为 1. 5%时,微球的平均粒径约 47μm,粒径分布最窄,约在 10~90μm;微球表面有孔,但随着BD含量的增加,微球表面变得相对粗糙,孔数减少,孔径减小,直至孔消失。更多还原

【Abstract】 A novel polyurethane microspheres was prepared with 1,6-hexamethylene diisocyanate(HDI)as the isocyanate, hydroxyl terminated D,L-poly(lactic acid) having low molecular weight as the diol, 1,4-butanediol(BD) as the chain-extending agent and PVP as supending agent, and suspension polymerization method was used. Effect of the content of BD on the microspheres morphology was studied with scanning electron microscopy(SEM).Effects of stirring rate and PVP concentration on particle-size and its distribution of microspheres were discussed by a SALD200 laser particle-size instrument. The chemical structure of microspheres was studied with Fourier transform infrared spectroscopy(FTIR).Results show that the mean particle-size of microspheres decreases and its distribution becomes wider with increase of stirring rate and PVP concentration. When stirring rate is 400 r/min and PVP concentration is 1.5%, mean particle-size is 47 μm,and its distribution ( from 15 μm to 90 μm) is the narrowest one. The microspheres are porous. However, with increase of the content of BD, the number of pores and the pore-size decreases until the pores disappears, and the surface of microspheres becomes rougher.更多还原