METHOD FOR MAKING LOW DENSITY POLYURETHANE FOAM FOR SOUND AND VIBRATION ABSORPTION

摘要

Flexible polyurethane foams that function well in noise and vibration absorption applications are made from a mixture of polyether polyols oxides that each has a hydroxyl equivalent weight of from 1200 to 3000 and at least 70% primary hydroxyl groups. From 5 to 80% by weight of the ethylene oxide-capped polypropylene oxides are nominally difunctional, from 0.5 to 20% by weight of the ethylene oxide-capped polypropylene oxides have a nominal functionality of four or higher, and the balance of the ethylene oxide-capped polypropylene oxides, but not less than 1.5% by weight thereof, are nominally trifunctional.