Abstract: Urea-formaldehyde polymers having reduced formaldehyde emissions are produced by incorporating in the prepolymer an aromatic substance incapable of reacting with urea formaldehyde in alkaline media but capable of reacting with urea formaldehyde in acid media in an amount sufficient to reduce or eliminate the free formaldehyde emissions therefrom. Also disclosed is a cellular urea-formaldehyde foam which is resistant to acid-induced hydrolysis, the foam prepared by incorporating a polyalkyl polynuclear metal sulfonate foaming agent in the acid catalyst solution for the urea-formaldehyde prepolymer.

Abstract: A method for producing stable urea-formaldehyde polymers which have reduced aldehyde vapor emissions during their production and use is disclosed, such urea-formaldehyde polymers particularly useful in the production of urea-formaldehyde insulating foam and as adhesives in the production of plywood and particleboard. An alkali or alkaline earth metal borohydride is added to the urea-formaldehyde resin solution prior to or during cure thereof. The boroydride reacts with free formaldehyde in the resin solution or any free formaldehyde subsequently generated in the resin due to hydrolytic break down. The amount of borohydride added the resin solution should be sufficient to reduce the emission of free formaldehyde therefrom.