Relationship Between Flame Retardation and Phase Transition Behavior of Polyester Fabrics Treated with a Bromine-Containing Compound

Poly (ethylene terephthalate) (PET) fabrics are treated with meso-1,2,3,4-tetrabro mobutane (TBB) to investigate flame retardation. The limiting oxygen index (LOI) value increases with an increasing amount of absorbed TBB (A TBB ) and reaches 28.1 % when A TBB is 10.20% owf. The slope of LOI is 1.14%/% owf from 0 to 4.65% owf of A TBB , and the slope decreases 0.31%/% owf at a region higher than 4.65% owf. The phase transition behavior of treated samples, investigated with differential scanning calorim etry, reveals that the depression of the melting initial temperature ( T m ) is directly proportional to the LOI value. Flory's equation for the depression of the melting point in polymer-diluent systems is applied to the PET-TBB system. We conclude that TBB molecules, which have strong affinities for PET segments in the region below 4.65% owf, show greater retardation for flammability.