Research on syntheses of degradable self-emulsified polyurethane microspheres

The self-emulsified polyurethane microspheres were synthesized by combining prepolymerization,chain-extension,neutralization and emulsification methods in one step.The synthetic conditions of self-emulsified polyurethane microspheres were researched.The conditions include the kinds of diisocyanates,the feed ratios of isophorone diisocyanate(IPDI) and polypropylene glycol(PPG),emulsification time,reaction time,polymerization time and stirred velocity etc.And the conditions affected morphology of microsphere and emulsion stability.The degradable self-emulsified polyurethanes(SEPUL) were synthesized with IPDI,PPG and poly(lactic acid)(PLA).And the degradation property was researched in phosphate buffer solution(PBS).The structure and morphology of polyurethane microspheres were measured with infrared spectrum and scanning electron microscope.We found the best conditions to synthesize the stable,mean and globose selfemulsified polyurethane microsphere.