Overview
The present invention provides a novel heat retardant material for polyurethane foam (PU foam) and polyurethane foam prepared there from. The introduction of covalently linked flame retardant organophosphonate ester into the PU foam is achieved by using the CuAAC click reaction of an alkyne-polyol and azidoalkylmonophosphonate . The functionalised PU foam demonstrated a well-formed polyhedral cell structure and an increase in the fire resistance properties by SEM and thermo gravimetric analysis, respectively. Even after thermal treatment at higher temperatures for e.g. at 400ºC, the new PU foam material displayed enhanced flame resistant properties by forming a char layer on the surface of the polymer, which, maintain its polyhedral structure.