Effect of flame retardants

Table 10. Effect of Flame Retardancy of Molybdenum Oxide and Antimony Oxide ...

Other substitutes were available, but a report by the New York State Environmental Protection Agency stated these were inferior to phosphate, posed an alkalinity hazard, and reduced the effectiveness of flame-retardant materials.10 Nevertheless, this did not stop the states of Indiana and New York from banning the sale of nearly all detergents containing phosphates in 1973. A number of other states, counties, and municipalities did not go this far, but limited the amount of STPP to... 

Nonwoven products ranging from medical disposables to automotive fabrics are required to meet specific flammability standards. These fabrics are generally composed of cellulosic and/or synthetic fibers which are flammable. Additionally, polymer coatings are applied to the fabric to impart properties such as strength, abrasion resistance and overall binding. It is the purpose of this paper to describe the various polymer coatings commonly used in the nonwovens industry and their effect on flammability of the substrates. Additionally, the effect of flame retardant additives, commonly used in latex formulations, will be discussed. 

Table V. Effectiveness of Flame Retardants (High Loft Polyester)...

This paper reports the results of a molecular-level investigation of the effects of flame retardant additives on the thermal dedompositlon of thermoset molding compounds used for encapsulation of IC devices, and their implications to the reliability of devices in molded plastic packages. In particular, semiconductor grade novolac epoxy and silicone-epoxy based resins and an electrical grade novolac epoxy formulation are compared. This work is an extension of a previous study of an epoxy encapsulant to flame retarded and non-flame retarded sample pairs of novolac epoxy and silicone-epoxy compounds. The results of this work are correlated with separate studies on device aglng2>3, where appropriate. 

M. Brebu, E. Jakab, and Y. Sakata, Effect of flame retardants and Sb2C>3 synergist on the thermal decomposition of high-impact polystyrene and on its debromination by ammonia treatment, J. Anal. Appl. Pyrolysis, 79(l-2) 346-352, May 2007. 

Present research efforts aim mainly at obtaining the important parameters from a study of the macrokinetics of combustion. It is important to estimate the effects of flame retardants, chemical structure of the polymer and polymer composition on variations of the solid- and gas-phase reaction kinetics. 

We considered it most rational to begin this paragraph with a discussion of the mechanistic concepts of the effects of flame retardants on the combustion of polymeric materials. 

Moreover, the sensitivity of the effect of a flame retardant to the ambient pressure should also be taken into account. Flame retardants that are active only in the gas phase usually fail to affect the composition of the volatile pyrolysis products and the coke yield. In this case whatever the nature of the polymer, the flame retarding element is released into the gas phase during combustion the type of oxidant (O /Nj, N O/N ) strongly affects the flammability. On the other hand the effect of flame retardants active in the solid phase depends on the polymer nature, but is independent of the nature of the oxidant. Variations of the pressure of the oxidative environment affect the rates of gas-phase as well as heterogeneous (interfacial solid-gas) reactions. 

In analogy with the manner in which flame inhibitors of gas systems are studied, the effects of flame retardants in polymer systems are analyzed by introducing them into the flame either on the fuel side or on the oxidant side Flames of monomers (polymer decomposition products) are used as models... 

Fig. 18. Effect of flame retardants on the yield of volatile components in the combustion of cotton fabric 1,1 ) PhjP and PhjPO 2,2 ) PhjP(OPh) and PhjP(0)(0Ph) 3,3 ) PhP(OPh)jand PhP(0)(0Ph)2 4, 4 ) P(OPh)3 and P(OXOPh)3 5) H3PO4 (After Ref. with permission)...

These theoretical discussions point up the need for determination of the mechanism of flameproofing, as well as of the relationship between the effectiveness of flame retardants and the distribution or availability of their active components for participation in different reactions. 

Glucopyranose, 4-acetamido-1,2,3,6-tetra-O-acetyI-4-deoxy-D-, 187 —, 5-amino-5-deoxy-D-, 116,132,133 —, 4-amino-4,6-dideoxy-/3-D-, 153 —, 1,4-anhydro-a-D-, from cellulose on heating, 441,442 —, 1,6-anhydro-jS-D-effect of flame retardants on pyrolysis of, 471... 

The pyrolysis products identified in this work are quite different from those observed by other investigators. The principal difference is that in our experiments the volatile products are flushed away rapidly by the carrier gas. This condition perhaps better simulates the state at the surface of a burning polymer. In any event, it is important in any study of the effect of flame retardants that identical techniques and experimental conditions be used in the study of polymer with and without the additives. 

A number of reviews on polymer photostabilisation have appeared as well as the effect of flame retardants and the use of melanin as a stabiliser in coatings/ ... 

Duske [7] also discussed several other techniques of value for this material. DSC can be used to check the oxidation resistance of the wire insulation by determination of the oxidation induction time (OFT) — an isothermal technique to determine when the oxidation will occur. Thermogravimetry (TG) has also been used to examine the decomposition of the insulation and the effectiveness of flame retardants. TMA is also useful for measuring the diermal expansion of the wire insulation and this technique is also applicable to multi-layered coatings. 

Table 3. Effect of flame retardants on colorability (fr resin versus neat polymer)...

Properties measured include thermal decomposition temperatures, relative thermal stability, chemical composition, and the effectiveness of flame retardants. TGA also is commonly used to determine the filler content of many thermoplastics. 

Yakushin, V. A., Stima, U. K., Zhmud, N. P. Effect of flame retardants on the properties of monolithic and foamed polyurethanes at low temperatures. Mechanics of Composite Materials, 35,447 50 (1999). 

Various workers have discussed the fire retardancy of polyvinylchloride (PVC) [55-59] using ammonium treated clay montmorillonite nanocomposites [52], hydroxyapatite nanocomposites [56] and antimony trioxide [57]. Lum [60] examined the effect of flame retardant additives on polymer pyrolysis reactions with a PVC composition containing 3 phr of SbiOs. It is well known that a synergistic flame retardancy effect is observed when SbiOs is incorporated into organic halide materials such as PVC. 

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