Poly (ethylene terephthalate) (PET) fabrics are treated with meso-1,2,3,4-tetrabromobutane (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 calorimetry, 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.Halogen-containing compounds are well known as effective flame retardants for polyester fibers and fabrics. A large number of studies of practical treatments for polyester fabrics by halogen-containing compounds have been reported [2, 3,9 ] , but the fundamental mechanisms of flame retardation of polyester fabrics treated with halogen-containing compounds have rarely been investigated. Lyssy assumed that halogencontaining compounds liberated from flame retardants act as radical acceptors in a flame zone [6]. Koch et al. suggested from thermogravimetric data that bromine-containing flame retardants mainly work in the gas-phase and not in the condensed phase [5]. On the other hand, Bostic et al., in their thermochemical study of the effects of a bromine-containing flame retardant on combustion, suggested that bromine may affect decomposition in a condensed phase, based on their heat of combustion data. [ 1 ] .As we noted above, there have been two theoriesthe gas-phase mechanism and the condensed phase mechanism-of the flame retardation of polyester fabrics treated with halogen-containing compounds. Recently, Nakanishi et al. made a thermoanalytical study of polyester fabrics treated with hexabromocyclododecane. They reported that the glass transition temperature, melting temperature, and crystallization temperature of treated polyester fabrics are depressed and the effect of flame retardation increases with increasing temperature depressions [7]. This fact implies that halogen-containing compounds act in the condensed phase, but no one can sufficiently explain why the depressions are related to flame retardation.In this study, we have treated polyester fabrics with a bromine-containing compound, meso-1,2,3,4-tetrabromobutane (TBB ), by sorption and investigated the relationship between flame retardation and thermal analytical behaviors obtained by differential scanning calorimetry in order to provide a satisfactory explanation..
ExperimentalSample preparation: Meso-1,2,3,4-tetrabromobutane (TBB) was commercially obtained from Tokyo Kasei Kogyo Ltd. PET fabric was the standard adjacent fabric for staining in the color fastness test, a...
