With the phase-out of hydrochlorofluorocarbon blowing agents at hand,a challenge facing polyester polyol producers is providing products to the polyurethane industry suitable for use with next generation blowing agents.New products must produce foams with an excellent balance of properties and concurrently maintain cost-effectiveness.As the choices of the alternative blowing agents post HCFC-141b become more defined,it is apparent that higher levels of water in formulations will be an important choice for formulators for reducing cost and reducing the use of flammable blowing agents.A menacing problem for suppliers of systems containing water is the reaction stability as it relates to aging and/or storage.In this paper,the role of various components of the polyol resin (including aromatic polyester polyols,catalyst and flame retardant) in the reaction stability of HC-and HFC-blown rigid foam systems will be presented.Recommendations for stability rigid foam systems containing aromatic polyester polyol and water will be provided.
展开▼
