Evaluation of flame retardants

Many factors influence the flammability of textiles, including the fibre type, the fabric weight and construction, the method of ignition, the extent of heat and material exchange, and the presence or absence of flame retardants. Differing 

16CFR 1610 Consumer Product Safety Commission (CPSC) Fabric at 45° angle to flame for 1 s. For general apparel. 

16CFR 1615/1616 CPSC Fabric held vertical to flame for 3 s. For children s sleepwear. 

NFPA1971 National Firefighters Protection Association (NFPA) Fabric held vertical to flame for 12 s. For protective clothing. 

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C.F. Cullis, Combustion of Flexible Polyurethane Foams. Mechanism and Evaluation of Flame Retardance , Combust Flame 24 (2), 217-30 (1975) CA 83, 82287 (1975)... 

In addition to dyeabiHty, polyesters with a high percentage of comonomer to reduce the melting poiat have found use as fusible biader fibers ia nonwoven fabrics (32,34,35). Specially designed copolymers have also been evaluated for flame-retardant PET fibers (36,37). 

The Green Screen for Safer Chemicals. The Green Screen for Safer Chemicals was successfully applied to evaluate three flame retardants that currently meet performance criteria for use in the external plastic housing of televisions (TVs). The three flame retardants evaluated are ... 

Air Products, a manufacture of latex binders, has completed a comprehensive study of flame retardants for latex binder systems. This study evaluates the inherent flammability of the major polymer types used as nonwovens binders. In addition, 18 of the most common flame retardants from several classes of materials were evaluated on polyester and rayon substrates. Two of the most widely recognized and stringent small scale tests, the NFPA 701 vertical burn test and the MVSS-302 horizontal burn test, are employed to measure flame retardancy of a latex binder-flame retardant system. Quantitative results of the study indicate clear-cut choices of latex binders for flame retardant nonwoven substrates, as well as the most effective binder-flame retardant combinations available. 

The focus of this program was to evaluate the environmental profiles of chemical flame-retardant alternatives for use in low-density polyurethane foam.93 The program was a joint venture between the Furniture Industry, Chemical Manufacturers, Environmental Groups, and the EPA to better understand fire safety options for the furniture industry. It assessed 14 formulations of flame-retardant products most likely to be used in this application. The project began in December 2003 and the report was issued in September 2005.94... 

The increasing demand for FR PVC-U applications has prompted work in this area. The use of functional fillers can cause a dramatic deterioration of physical properties at the addition levels necessary to achieve the requirements of flame retardancy and smoke emission. An evaluation has shown zinc hydroxystannate to give the best overall FR and SS characteristics without adversely influencing important physical properties (129). The addition of low levels of zinc borate and/or ATH was noted to improve flame retardancy and reduce smoke density in a PVC-U formulation (265). 

This study resulted in a series of reports on a comprehensive evaluation of fire-retardant treatments for wood (2-6). One hundred and thirty single chemicals or combinations of chemicals in the form of various salts were evaluated for flame-spread reduction, smoke, and corrosivity. Diammonium phosphate ranked first in reducing flame spread, followed by monoammonium phosphate, ammonium chloride, ammonium sulfate, borax, and zinc chloride. Zinc chloride, although excellent as a flame retardant, promoted smoke and glowing. Ammonium sulfate was the least expensive, but under certain environmental conditions it was corrosive to metals. None of the 130 compositions tested was considered ideal because of the adverse effects on some of the properties of wood. Several reviews of the subject are available and provide additional background material (J, 7-JO). 

Selection of Fire Retardants. The choice of flame retardants depends on the nature of the polymer, the method of processing, the proposed service conditions, and economic considerations. Although the processing, service, and economic factors are impor.pa tant, the flame-retardancy potential of an additive is of primary importance, and this factor can be readily evaluated by thermal analysis. 

There has been considerable progress in detailed evaluation of a large number of flame-retardants in a variety of plastics. Many useful reviews of results have been published, e.g., self-extinguishing polyester resins [6]. At the same time, the number of flame-retardant patents has grown enormously, especially in the United States [7, 8], which suggests an intensification of industrial interest in this field which must have run parallel with advances in legislation on this subject. 

The development of flame retardant additives for polymeric materials that could simultaneously promote both gas-phase and solid-phase types of action could result in products that are both more cost-effective and more environmentally-friendly than those currently in use [69]. These include bromoanilino triazine derivatives and bromoaryl phosphates. Both have the potential to display both solid-phase and gas-phase FR activity. These were evaluated by a variety of thermal methods. Some of these compounds had the potential to display dual functional behaviour as FR, i.e., to maintain the good gas phase activity associated with organohalogen compounds while, at the same time promoting the development of protective char at the solid phase. 

In the present chapter, we report some of om study on both raw and surface-modified Grewia optiva fiber-reinforced UPE matrix-based composites, which possess enhanced mechanical and physico-chemical properties when compared with UPE matrix. In addition to the effect of flame retardants, i.e., magnesium hydroxide and zinc borate, on flame resistance, the behavior of resulted Grewia optiva fiber-reinforced composites have also been evaluated and was foimd to be improved. A significant discussion on the work of other researcher s work has also been added in the chapter. 

A number of halogenated epoxy resins have been developed and commercialized to meet specific application requirements. Chlorinated and brominated epoxies were evaluated for flame retardancy properties. The brominated epoxy resins were found to have the best combination of cost/performance and were commercialized by Dow Chemical in the late 1960s. 

Photochemical studies on the deterioration of flame-retarded polyester fabrics using a Xenon-arc have been reported and physical properties have been evaluated. ... 

Quantitative analysis of volatile products by TD-GC-MS has been used to evaluate the performance of flame retardants in EPs such as PC, PPE and PBT [75]. McGrattan [76] has described the quantitative analysis of volatile products of programmed degradation by trapping in a chemical... 

This means that polymer flammability decreases when LOI increases. This method is also used to test the efficiency of flame retardants, but it is necessary to mention the direction of gas flow while testing (i.e., if the gases are coming from above or below the burning sample) [11]. Relative flammabilities as determined by LOI do not always agree with results from other tests it is thus necessary to know these results for a good evaluation of the flammability of plastic materials. Table 12.2 shows that there is no direct relation between LOI and the enthalpy or heat content for some polymers. 

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