Abstract: Substantially closed cell rigid polyurethane foam cores of laminates are disclosed which are scorch-free, have a density of 50 kg/m.sup.3 and are made using water as the sole or main blowing agent and without the need to use a CFC. The foams are prepared from polyol compositions comprising the product of alkoxylating an initiator having a functionality of more than 2, at least one aromatic ring and at least one amino nitrogen atom. The initiator is preferably a Mannich condensate of a phenolic compound, formaldehyde and ammonia or an alkanolamine and the polyol is preferably used together with a second polyol having a functionality (or average functionality) of at least 1 but less than 3 and a molecular weight M.sub.w (or average molecular weight) of 250 to 4000.

Abstract: Isocyanate-derived foams are prepared from an isocyanate, catalyst, blowing agent, foam stabilizing surfactant and at least two active hydrogen-containing compounds wherein one of the active hydrogen-containing compounds is an alkylene oxide polymer having an equivalent of at least 300 and being composed of at least about 10 weight percent, based on a total weight of the polymerized alkylene oxide in the polymer, of a polymerized ethylene oxide.