Synthesis and flame-retardant properties of phosphorus-containing polymers based on poly(4-hydroxystyrene)

Phosphorus-containing polystyrene was obtained through incorporating phosphate groups onto poly(4-hydroxystyrene). This was achieved by esterification with diethylchlorophosphate. The phosphorylation was confirmed by IR, H-1-NMR, and P-31-NMR analysis. By varying the feeding ratios of the reactants, the phosphorus content in the polymers could be successfully tailored and gave values of 12.8 to 4.9% by weight. This was further corroborated by elemental analysis. Thermal characteristics and temporal stability of the phosphorylated polymers were evaluated by DSC and TGA. High char yields (64% by weight) and LOI values of 41 were found for these polymers. Such properties make these polymers useful in flame retardants. (C) 1996 John Wiley & Sons, Inc.