abstract |
A rigid polyurethane foam formulation comprising a polyester polyol having a hydroxyl number of from 150 to 600 mg KOH/g and a functionality of at least 2, a blowing agent comprising water and an auxiliary blowing agent, a non-silicone organic surfactant, greater than 0.1% to less than 3.7% of a cyclic siloxane, by weight based on the total weight of the foam formulation, a catalyst, and optionally a flame retardant; and a polyisocyanate; such that the isocyanate index is in the range of from 100 to 500, a rigid polyurethane foam formed from the foam formulation; and a method of forming a rigid polyurethane foam. |