POLYURETHANE SEALING FOAM COMPOSITIONS PLASTICIZED WITH FATTY ACID ESTERS

摘要

Plasticized polyisocyanate compositions contain (a) an isocyanate terminated reaction product of a polymeric MDI with a difunctional poly(propylene oxide) homopolymer or difunctional copolymer of at least 85% by weight propylene oxide and up to 15% by weight ethylene oxide, which homopolymer or copolymer has a molecular weight of from about 400 to 2200 and (b) at least one alkyl ester of one or more fatty acids, the polyisocyanate composition having an isocyanate content of from about 8 to about 14% by weight and a Brookfield viscosity of no greater than 5000 cps at 25° C. The plasticized prepolymers are particularly useful in foam formulations for insulating cavities in automotive parts and thermal insulating panels such as the walls of buildings or appliances.