| Abstract: | Disclosed is a method for making a polyurethane closed-cell foam material
exhibiting a bulk density below 4 lbs/ft.sup.3 and high strength. The
present embodiment uses the reaction product of a modified MDI and a
sucrose/glycerine based polyether polyol resin wherein a small measured
quantity of the polyol resin is "pre-reacted" with a larger quantity of
the isocyanate in a defined ratio such that when the necessary remaining
quantity of the polyol resin is added to the "pre-reacted" resin together
with a tertiary amine catalyst and water as a blowing agent, the
polymerization proceeds slowly enough to provide a stable foam body. |