Michael K. Laughner

New Polyol Development in Rigid Hybrid Polyurethane/Polylsocyanurate Foam Systems

For over 25 years, rigid urethane foams have been highly regarded for their thermal insulation properties and are preferred over competing materials in applications where increased energy efficiency is of prime importance. In recent years, a major concern of the insulation industry h~s been the improved fire retardancy of cellular plastic in general, and specifically with the smoke generation and burn properties of rigid polyurethane foams. The first efforts to reduce polyurethane foam flammability were through the use of reactive and nonreactive halogen and/or phosphorus additives. These foams suffered from high cost, instability in formulated systems, loss of fire retar-