FLAME RESISTANT COTTON BY PHOTOINITIATED GRAFT CO-POLYMERIZATION

Photoinitiated, free‐radical reaction of cotton fabric with vinyl phosphonate oligomer (molecular weight 500–1000) and N‐methylolacrylamide monomer from aqueous solutions to form copolymer gave a textile product that had flame resistance (FF 5‐74 test). The initiating free radicals were formed on the cellulose molecule when cotton fabric was exposed to ultraviolet radiation. The effects of wavelengths of ultraviolet radiation (254, 300, and 350 nm), reaction time (0–9 ksec), solids in solution (10%–60%), atmosphere (air, nitrogen, and oxygen), and oligomer‐to‐monomer concentration (1:0.00 to 1:1.20 mole ratio) on efficiency of monomer and oligomer conversion to copolymer (maximum efficiency 70%–80%) were determined. Evaluation of the flame resistant cotton fabric by transmission electron microscopy showed deposits of copolymer throughout the cross sections of the fibers. However, scanning electron microscopy and energy‐dispersive x‐ray analysis showed that copolymer and phosphorus tended to be more concentrated between and on the surfaces of the fibers. Copyright © 1979 John Wiley & Sons, Inc.