Flame retardants interactions with

The ABS component and its flame retardant interact with both PVC and PET in the course of thermal decomposition (135,139). 

Flame-retardant additives are capable of significant reduction in the ha2ard from unwanted fires, and techniques are now available to quantify these improvements. Combined with an understanding of fire-retardant mechanisms, polymer-retardant interactions, and reuse technology, formulations optimi2ed for pubHc benefit and manufacturing practicaUty can be selected. 

Chemical Interaction. Halogens and some phosphoms flame retardants act by chemical interaction. The flame retardant dissociates into radical species that compete with chain propagating and branching steps in the combustion process. 

One noteworthy neurotoxic response was demonstrated in laboratory pyrolysis studies using various types of phosphoms flame retardants in rigid urethane foam, but the response was traced to a highly specific interaction of trimethylolpropane polyols, producing a toxic bicycHc trimethylolpropane phosphate [1005-93-2] (152). Formulations with the same phosphoms flame retardants but other polyols avoided this neurotoxic effect completely. 

The quantitative relationship of flammability of a polymer with respect to the concentration of flame retardant is usually not linear, and there is no logical reason to expect combinations of different flame retardants to show a linearly additive result either (43). The actual result is often found to be "synergistic" or "antagonistic", or in regression analysis terminology, the interaction term is often found to be statistically significant. 

More recently, based on the results of an extensive series of small scale degradation studies, two additional mechanisms for the volatilization of antimony from antimony oxide/organohalogen flame retardant systems have been proposed (23,24). Of these two proposed mechanisms, [4] and [5], [4] does not involve HX formation at all and [5] suggests an important role for the direct interaction of the polymer substrate with the metal oxide prior to its reaction with the halogen compound. 

Bromine is applied to flame retarding (FR) polymers in a number of systems, which are divided into two major groups, according to the way in which the FR agent interacts with the polymer [1). In one group, e.g. the reactive systems, the bromine is chemically bound with the polymer. The introduction of the bromine into the polymer molecule can be carried out by copolymerizing a bromine-containing... 

Phosphorus flame retardants, 77 484-510 additive organic, 77 488-489 commercial, 77 487-499 economic aspects of, 11 503 in epoxy resins, 77 499-501 health, safety, and environmental factors related to, 77 501-503 interaction with other flame retardants, 77 486... 

The SSP behavior of co-polyesters with rigid or voluminous comonomers, such as the flame retardant additive 9,10-dihydro[2,3-di-9-oxa-(2-hydroxyethoxy)-carbonylpropyl]-10-phosphaphenanthrene-10-oxide, or the ionic compound, sodium 5-sulfoisophthalate, is inhibited. This also occurs in the melt phase and cannot be improved by the use of catalysts [56], The results of studies examining the influence of employed catalysts with respect to stability and quality of the polymer suggest the use of antimony catalysts. The thermal or thermo-oxidative stability is, however, reduced by the interaction of the catalyst with the carboxylic groups of the polymer [57],... 

Meerts lA, van Zanden JJ, Luijks EA, van Leeuwen-Bol I, Marsh G, Jakobsson E, Bergman A, Brouwer A (2000) Potent competitive interaction of some brominated flame retardants and related compounds with human transthyretin in vitro. Toxicol Sci 56 95-104 Mengel K (1985) Dynamics and availability of major nutrients in soils. Adv Soil Sci 2 67-134 Mercer JW, Cohen RM (1990) A review of immiscible fluids in the subsurface Properties, models, characterization, and remediation. J Contam Hydrol 6 107-163 Mertens JA (2000) Trichloroethylene. In Kirk-Othmer Encyclopedia of Chemical Technology. Wiley New York. Available at http //www.mrw.interscience.wiley.com/emrw/9780471238966/ kirk/article/tricmert.aOl/current/pdf... 

Meerts lA, van Zanden JJ, Luijks EA, et al. 2000. Potent competitive interactions of some brominated flame retardants and related compounds with human transthyretin in vitro. Toxicol Sci 56(1) 95-104. 

It is concluded that the difference in flame retardancy mechanisms of phosphorous flame retardants is due to the different decomposition pathways and interactions between flame retardant and polymer or their decomposition products, respectively. The release of phosphorous-containing molecules into the gas phase competes with char-inducing or inorganic residue-forming interactions... 

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