| abstract |
There is now provided a closed cell rigid polyurethane foam made from a polyol composition containing a polyol having polyester linkages and a number average molecular weight of 400 or more, and at least about 8 php of a silicone-containing surfactant polymer. Either mixed into the polyol composition at the time of foaming, mixed into an isocyanate, or both, is an aliphatic or cycloaliphatic C4-C7 hydrocarbon. |