Process for making a polymer polyol having monodispersed dispersed polymer particles

摘要

A polymer polyol is made in a seeded process, in which styrene and acrylonitrile are polymerized in the presence of a base polyol, a seed dispersion, and a solvent. The seed dispersion contains the unsaturated macromer. The process produces a polymer polyol, the dispersed phase particles having a particle size of 1 to 3 μm and a particle size span of less than 1.25. Polymer polyols are very useful for making flexible polyurethane foams in cushioning applications where high air flow and good load bearing are required.