Abstract: Improved methods are provided for incorporating carbon dioxide and carbon dioxide generating compounds into polyurethane foam forming compositions as blowing agents to eliminate or reduce the amount of low boiling liquid auxiliary blowing agents, such as methylene chloride and chlorofluorocarbons conventionally used in the manufacture of urethane foams.

Abstract: Improved, flexible, open celled polyurethane foams are described. The foams are formed in situ from the reaction of a polyisocyanate, a conventional polyester polyol, a polyether polyol, a high hydroxyl polyester polyol and a blowing agent in the presence of a catalyst. A polyether foam stabilizer is normally also included. A small amount of a destabilizing silicone ingredient can also be included. Useful high hydroxyl number polyester polyols have hydroxyl numbers in the range 300-600, and preferably 400-450. The average equivalent weight of the useful high hydroxyl number polyester polyol is normally in the range 100-200. The compositions of the invention are useful as filter media and are especially suitable for outdoor seating applications.