Synthesis and characterization of polyurethaneurea–vinyl polymer (PUU–VP) uniform hybrid microspheres by SPG emulsification technique and subsequent suspension polymerization

Abstract Uniform polyurethaneurea–vinyl polymer (PUU–VP) hybrid microspheres of about 20 μm were prepared by a Shirasu porous glass (SPG) membrane emulsification technique and a subsequent radical suspension polymerization process, that is, a mixture of a 40 wt % urethane prepolymer (UP) solution of xylene and a vinyl monomer (VP) containing an initiator was permeated through the uniform pores of the SPG membrane into a continuous phase containing a stabilizer to form uniform droplets. Then, the droplets were allowed to stand for chain extension at room temperature with di‐ or triamines for 2 h in the absence or presence of ethyl acetate (EA), followed by suspension polymerization at 70°C for 24 h. The effect of the type and the amount of the monomer composition, crosslinker, and chain extender on the monomer conversion, particle morphology, and stability of the dispersion was investigated. A strong relationship was found between the compatibility of PUU with VP and the stability of the dispersion. The monomer conversion increased and the stability of the dispersion was improved as the amount of the crosslinker was increased. Solid and spherical PUU–VA hybrid particles with a smooth surface and a higher destructive strength were obtained when a trifunctional crosslinker and a chain extender were used together. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 163–178, 2003