| abstract |
A polyol formulation comprising certain types of polyester polyols useful in the preparation of rigid polyurethane foams having low level surface friability. In one embodiment, a reaction system is provided for the production of a rigid foam. 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 20 to 60% by weight of an aromatic component comprising at least 80% molar or more of terephthalic acid, 20 to 60% by weight of polyethylene glycol having an average molecular weight in 150 to 1,000, 5 to 20% by weight of a glycol having a functionality of 2 and a molecular weight of 60 to 250 and 5 to 20% by weight of a glycol having a functionality of at least 3 and a molecular weight of 60 to 250. |