Foamed polymers containing low molecular weight urethane modifier

Abstract

Foamed polymers such as polyurethanes useful, for instance, as cushioning, insulation, and in reaction injection molding to produce thin section moldings can be produced without substantial reduction in physical properties by the incorporation therein of about 2 percent to about 75 percent by weight based upon the weight of said polymer of at least one non-reactive, liquid urethane modifier compound processing aid or flame-retardant additive. Said modifier has a low viscosity at ambient temperatures and is a low-molecular weight urethane adduct formed by the reaction of (1) at least one polyisocyanate and at least one monohydric alcohol or (2) at least one monofunctional isocyanate with at least one monohydric or polyhydric alcohol or (3) at least one isocyanate-terminated quasi-prepolymer with at least one monohydric alcohol. Said modifier can also consist of mixtures of (1), (2), and (3). Utilizing halogenated alcohols, flame-retardant polymer foams such as polyurethane foams can be prepared. Unexpectedly, microcellular, rigid, high-resilience, and flexible foamed polyurethanes can be prepared utilizing substantial proportions, such as flame-retardant amounts, of the modifier compound without substantial reduction in physical properties of the foam.