Studies on syntheses,structure and morphology of polyurethane microcapsule

Polyurethane(PU) water solutions were synthesized and PU microcapsules were synthesized with the coacervation phase separation method.The influencing factors of PU microcapsules were investigated including the kinds of diisocyanate the molecular weight of polyethylene glycol(PEG),the mole ratios and the grosses of monomers and the concentrations of CaCl2.The structure and morphology of the PU microcapsules were measured by fourier transform Infrared spectroscopy(FTIR) and scanning electron microscope(SEM).The results show that the optimal conditions of synthesizing the spherical PU microcapsules are as follows: the mole ratio of IPDI and PEG(200) is 6∶2,the grosses of monomers are 45%,the concentrations of CaCl2 are more than 4%.The results of FTIR indicate that the synthesizing microcapsules are PU microcapsules.The results of SEM reveal that PU microcapsules are smooth sphericity,The surfaces are provided with porosity,the diameter of the PU microcapsules is 3mm or so,the diameter of cavities in PU microcapsules is 2mm or so.