Synthesis of trimethylolphosphine carbamate and its flame retardant application in cotton

Abstract

A novel free‐halogen flame retardant (trimethylolphosphine carbamate, THPON) was synthesized through the simple reaction between tetrakis(hydroxymethyl) phosphonium chloride and urea. Small molecule THPON could infiltrated the cotton fibers and grafted on cotton cellulose by amide bond. What is more, THPON did not change the inherent crystal structure of cotton because it infiltrated into the amorphous region of cotton. THPON‐treated cotton was easily decomposed into phosphoric acid or polyphosphate at lower temperature and exhibited good flame retardancy due to the N/P synergistic effect. Compared to control, the heat release rate of THPON‐treated cotton increased slower, indicating that a protective carbon layer formed and acted as a barrier. In addition, THPON displayed the low cytotoxicity and biosafety. The development and properties of THPON could provide an important data for the further application in the industry.