Boron-containing fire retardant rigid polyurethane–polyisocyanurate foams: Part I – polyol precursors based on boric acid and di(hydroxymethyl)urea derivatives

Development of a method for synthesis of boroorganic polyols based on boric acid and di(hydroxymethyl)urea derivatives is described. The polyols obtained were characterized in terms of their suitability for production of rigid polyurethane–polyisocyanurate foams, with infrared and nuclear magnetic resonance analyses confirming the presence of active hydroxyl groups. Results obtained from the determination of density, viscosity and hydroxyl number enabled formulation of the polyols for use in the production of fire retardant rigid polyurethane–polyisocyanurate foams, the preparation and properties of which are described in Part II of this article.