POLYOL FORMULATIONS FOR IMPROVED COLD TEMPERATURE SKIN CURE OF POLYURETHANE RIGID FOAMS

A polyol formulation comprising certain type of polyester polyols useful in the preparation of rigid polyurethane foams having low surface friability is provided. In one embodiment, a reaction system for production of a rigid foam is provided. The reaction system comprises a polyester polyol and one or more polyisocyanates, wherein the polyester polyol and the polyisocyanates are mixed in amounts sufficient to provide a rigid polyurethane foam. The polyester polyol comprises the reaction product of from 20 to 60 weight percent of an aromatic component comprising at least 80 mole percent or greater of terephthalic acid, from 20 to 60 weight percent of a polyethylene glycol having a number average molecular weight from 150 to 1,000, from 5 to 20 weight percent of a glycol having a functionality of 2 and molecular weight of 60 to 250 and from 5 to 20 weight percent of a glycol having a functionality of at least 3 and a molecular weight of 60 to 250.