Synthesis and characterization of polyurethane microspheres

A novel particle forming polymerization technique for the preparation of polyurethane microspheres with particle size in the range 0.1-100 micron is described. The method is general, applicable to wide variety of diols and isocyanates and is very simple. The key to successful particle forming polymerization is the use of novel steric stabilizers, such as, a reactive diol containing two primary hydroxyl groups with a long hydrophobic acrylate ester moiety and an amphiphilic block copolymer. The effect of various reaction variables on the particle forming polymerization process will be discussed.