A crosslinked vinylidene chloride polymer microgel powder is recovered from a latex and dispersed with moderate shear in a nonsolvent for vinylidene chloride polymers, such as a polyol used in the preparation of polyurethane materials. A dispersion of the powder and a polyol is eminently suited for use in the preparation of polyurethane foams to impart enhanced flame-retardancy and load-bearing properties thereto.
