摘要 |
Polyisocyanurate foams are prepared by reacting together an organic polyisocyanate, a blowing agent, a trimerization catalyst, and a minor amount of a polyol mixture prepared by digesting polyalkylene terephthalate, particularly polyethylene terephthalate, with a polyol, especially a glycol. Laminates of such foams exhibit a high degree of fire resistance, low smoke evolution on combustion, low foam friability and high compressive strength.
|