Flame retardant textile back-coatings. Part 1: Antimony-halogen system interactions and the effect of replacement by phosphorus-containing agents

A series of back-coated cotton fabrics comprising varying molar ratios of c hlorine, bromine and antimony has been studied using a simulated match igni tion test, LOI and thermal analysis (TGA and DTA). Results show that the presence of chlorine alone and in combination with br omine increases LOI and carbonaceous char values at optimum halogen:antimon y molar ratios of 2.5-3.6:1 and bromine:chlorine molar ratios within the ra nge 0.31-0.42. Only bads-coated samples containing bromine pass the simulat ed match test although at Br:Sb molar ratios above 4:1, LOI and char residu al values decrease. It is evident that condensed and vapour phase flame ret ardant mechanisms are operating with efficiencies determined by halogen:Sb and Br/Cl molar ratios. Partial and whole replacement of halogen and antimony by phosphorus-contain ing and other flame retardants in the back-coating formulation that do not function in the vapour phase may be used to pass the simulated match test.