Abstract: This invention relates to the process for the preparation of aqueous polyurethane dispersions, which comprises preparing an isocynate terminated carboxyl group containing prepolymer, by preparing a solution of a polyol in an organic solvent, adding an ionic group containing compound to this solution, heating this mixture at a controlled temperature, adding an isocyanate in the reaction mixtute optionally in the presence of a catalyst depending upon the isocynate, stirring, neutralizing and cooling the mixture at ambient temperatures and finally dispersing the mixture in water to obtain the product.

Abstract: This invention relates to the process for the preparation of polyurethane with controlled particle size and shape. More, particularly it relates to the production of polyurethane microspheres from a diol and diisocyanate by dispersion polymerization in presence of a steric stabilizer and a catalyst in an organic solvent at a controlled temperature, and finally separating the spherical polyurethane particles from the reaction mixture by conventional means.

Abstract: This invention relates to the process for the preparation of macromonomers with more than one polycondensable functional groups with equal reactvity, which comprises reacting a carboxyl or hydroxyl terminated prepolymers, with an organic compound containing two or more isocynnate reactive functional groups, in the presence of a dehydrating agent and a non-reactive solvent at ambient temperatures, separating the product from the reaction mixture by conventional means.