| abstract |
A polyurethane or polyisocyanurate foam composition comprising: a polyol or a mixture thereof; an isocyanate; a polyurethane catalyst or a mixture thereof; a modified phenolic resin, the modified phenolic resin being an oxyalkylated phenolic resin wherein at least 50 mol%, preferably 75 mol% or more, of the phenolic hydroxyl groups have been modified to provide primary hydroxyl groups, wherein the phenolic resin is modified with an alkylene carbonate; and the composition has an isocyanate index of about 250 or less; a surfactant; one or more blowing agents selected from a physical blowing agent or a mixture thereof, a chemical blowing agent or a mixture thereof, or any combination thereof; and optionally, a flame retardant additive or a mixture of them. |