New Generation Polyether Polyols for Improved Performance of Reactive Hot Melt Adhesives, 1998 Hot Melt Symposium Proceedings

High performance hot melt applications require superior peel strength and thermoset properties in the final cure. Polyurethane reactive hot melt (RHM) adhesives often meet these higher performance requirements. Commercial reactive hot melt resins are typically made with pure MDI (Methylenediphenyl diisocyanate) prepolymers of adipate-based polyester polyols. Work 1 has been presented on the feasibility of using an all polyether polyol-based isocyanate-terminated prepolymer in RHM adhesive formulations. The RHM adhesive performance of polyurethane prepolymers prepared with MDI and polyether polyols was tested specifically for initial viscosity, peel strength, tack free time and melt stability. The results demonstrated that it is possible to produce polyether polyol-based polyurethane RHM adhesives with performance comparable to those obtained from polyester polyols. In this paper we will present a new generation of polyols and their performance characteristics in RHM adhesive formulations which demonstrate higher initial peel strength.