Graft copolymers from unsaturated monomers and azo di-ester polyols and polyurethanes prepared therefrom

Claim 1

In a process for preparing a polyurethane foam from a reaction mixture comprising an organic polyisocyanate, a foaming agent, and a polyol reactant, the improvement characterized by including a polyol reactant which comprises a graft copolymer prepared by polymerizing an ethylenically unsaturated monomer or mixtures of such monomers in the presence of an azo di-ester polyol of the formula: ##STR9## wherein: m and r independently represent integers from 2 to 5, n and p independently represent integers from 0 to 5, R 2 and R 3 independently represent alkyl of 1-4 carbons, and ((HO).sub.m --R.sub.1 --O-- and --O--R.sub.4 --(OH).sub.r) independently represent residues of polyether or polyester polyols, R 1 (OH) m+1 and R 4 (OH) r+1 , having an average equivalent weight ranging from about 250 to 5000, after removal of one hydroxy hydrogen therefrom, wherein R 1 and R 4 independently represent polyether polymer portions and polyester polymer portions thereof, said polymerizing occurring at a temperature at or above which the azo-carbon linkages of the azo di-ester polyol are ruptured.