New UV-curable cyclotriphosphazenes as fire-retardant coating materials for wood

Abstract

A series of (2-hydroxyethylmethacrylate)(n-propoxy)cyclotriphosphazenes (HPCP) has been prepared by the reaction of N3P3Cl6 with n-propanol and 2-hydroxyethylmethacrylate (HEMA) sequentially in the appropriate solvents. These phosphazene compounds are characterized by a combination of Fourier transform infrared, ultraviolet, and nuclear magnetic resonance spectroscopies. It was found that the compounds were soluble in most of the organic solvents, exhibited an absorption between 207–216 nm, and were curable by UV irradiation. After curing, the surfaces of the HPCP-coated woodblocks were transparent and had a fire-retardant property, which has been ascribed to the intumescent behavior during the burning process. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 115–122, 1998