And zinc borate

Addition of fillers such as alumina trihydrate, antimony trioxide, molybdenum oxide [315], zinc borate and zinc borate complex [316] leads to increase in TS but decrease in elongation and NG migration/absorption. Addition of inorganic fillers also leads to increase in flame retardance. 

The flame retardant mechanism of PC/ABS compositions using bisphenol A bis(diphenyl phosphate) (BDP) and zinc borate have been investigated (54). BDP affects the decomposition of PC/ABS and acts as a flame retardant in both the gas and the condensed phase. The pyrolysis was studied by thermogravimetry coupled with fourier transform infrared spectroscopy (FUR) and nuclear magnetic-resonance spectroscopy. Zinc borate effects an additional hydrolysis of the PC and contributes to a borate network on the residue. 

Braun, U., Schartel, B., Fichera, M.A., and Jaeger, C. 2007. Flame retardancy mechanisms of aluminium phosphinate in combination with melamine polyphosphate and zinc borate in glass-fibre reinforced polyamide 6,6. Polym. Deg. Stab. 92 1528-1545. 

Journal of Applied Polymer Science 89, No.3, 18th July 2003, p.753-62 MECHANOCHEMICAL IMPROVEMENT OF THE FLAME-RETARDANT AND MECHANICAL PROPERTIES OF ZINC BORATE AND ZINC BORATE-ALUMINUM TRIHYDRATE-FILLED POLY (VINYL CHLORIDE)... 

Consumption of halogenated additives is expected to decline as the market moves towards synergistic systems that mix flame retardants such as antimony oxide, phosphorus, and zinc borate with a halogen [15],... 

Less than 10% of the polyamide produced is made in a flame retardant version. The best system is composed of a combination of red phosphorus and zinc borate (see table above). The only drawback of this system is its color which is restricted to brick red or black. If other colors are required, ammonium polyphosphate is used either in combination with organic flame retardants or with antimony trioxide. It is possible to manufacture a very wide range of colors in the halogen free system. Some systems make use of the addition of novolac or melamine resins. For intumescent applications, ammonium polyphosphate, in combination with other components, is the most frequently used additive. Figure 13.6 shows that fillers such as calcium carbonate and talc (at certain range of concentrations) improve the effectiveness of ammonium polyphosphate. This is both unusual and important. It is unusual because, in most polymers, the addition of fillers has an opposite influence on the efficiency of ammonium polyphosphate and it is important because ammonium polyphosphate must be used in large concentrations (minimum 20%, typical 30%) in order to perform as a flame retardant. 

Aluminum trihydrate, magnesium hydroxide, calcium and zinc molybdates, antimony pentoxide, and zinc borate are examples of inorganic compounds used as flame retardants in the manufacture of household furniture, upholstery, wall coverings, draperies, and carpets (National Research Council (NRC), 2000). Antimony trioxide is sometimes used in combination... 

Recent studies have demonstrated that there are major advantages in using a combination of ATH and zinc borate in a variety of halogen-free polymer systems. 

Both triaryl phosphate and zinc borate are effective flame retardants in m-PPO, but not in HIPS. The m-PPO is a higher heat pol5mer than HIPS, with m-PPO processed at temperatures where... 

Flame Retardants. Hydrocarbon elastomers are flammable and thus require flame retardants if their service conditions include the possibihty of fire. Alumina trihydrate, magnesium hydroxide, and zinc borate are used, because they give off blanketing vapors at high temperatures. Also, typical flame-retardant systems include chlorinated paraffins or brominated aromatic resins in combination with antimony trioxide. 

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. 

Other examples of chlorinated additives include chlorinated alkyl phosphates with main applications in rigid and flexible polyurethane foams and chlorinated cycloa-liphatics such as dodecachlorodimethanodibenzocydooctane. The latter is used with various synergists such as antimony trioxide and zinc borate in numerous polymers including polyamide, polyolefins, and polypropylene. 

He M, Cao WC, Wang LJ, Wilkie CA (2013) Synergistic effects of organo-sepiolite and zinc borate on the fire retardancy of polypropylene. Polym Adv Technol 24 1081-1088... 

Nelson [136] has reported studies of zinc, zinc oxide, and zinc borate in coatings on or as a filler in modified polyphenylene oxide (m-PPO). Zinc arc spray, or zinc, zinc borate, and zinc/zinc borate in epoxy coatings showed a substantial reduction of flame spread index (ASTM E-162) (I,) for m-PPO. Zinc oxide in epoxy, however, showed a dramatic increase in I, on m-PPO. Zinc arc spray on m-PPO led to enhanced stability in the 500-600°C range in both isothermal and GC/MS experiments. It was speculated that since zinc melts at 420OC, just at the early stage of decomposition of m-PPO, this could allow intimate contact with the charring substrate. As in pure polystyrene, char formation is enhanced in air in m-PPO, and this was thought to be enhanced further by the presence of zinc. Indeed it was observed that volatilization of small molecules is reduced for m-PPO with zinc present at temperatures under 700°C, with preference for volatilization of the triaryl phosphate flame retardant, styrene trimer, and PPO dimers. 

Commercial chemical fibers are combustible in nature, and improved FR properties must be considered in actual application. Most FR additives contain bromine (Br), chlorine (Cl), phosphorus (P), antimony, or aluminum. Among them, commonly used additives are additive brominated hydrocarbons and reactive brominated hydrocarbons, nonhalogenated phosphate esters, halogenated phosphate esters, trioxide antimony oxide, pentoxide antimony oxide and sodium derivatives, chlorinated hydrocarbons like chlorinated paraffin, and chlorinated cycloaUphatics. Others include chlorinated or brominated compounds, fluorinated compounds, magnesium carbonate, magnesium hydroxide, melamine, molybdenum compounds, silicone polymer, and zinc borate. Sometimes, polymers are chemically modified, and N, P, Cl, fluorine (F), silicon (Si), and Br elements can be introduced into the polymer main chain [49]. 

In halogen-containing polymers, the zinc borate can either partially or completely replace antimony oxide as a fire retardant synergist of halogen sources. The combination of antimony oxide and zinc borate can provide not only cost savings but also synergism in fire test performances (Figure 2). In addition, in contrast to antimony oxide, the zinc borate also... 

Shen et al. " reported on flame retardant improvements by using a filler combination of modified montmorillonites, MDH, and zinc borate in EVA. A modified montmorillonite with a smaller particle size gave a better UL-94 performance than one of a larger particle size, and a stronger char was formed during the presence of zinc borate with a very fine particle size. 

In halogen-containing PO, a typical formulation for wire and cable application consists of decabromodi-phenyl oxide or Dechlorane Plus, antimony oxide and zinc borate. It is interesting to note that, in presence of Irganox 1010, the zinc borate can significantly improve the physical properties of the wire and cable... 

Additives that impart smoke-suppressant properties to a composition tend not to be flame retardant. Conventional flame retardant and smoke-suppressant formulations include phosphorus-containing compounds such as a phosphoric acid ester, ammonium poly(phosphate) and red phosphorus, or halogen containing compounds such as tetrabromobisphenol A, decabromodiphenyl oxide and chlorinated polymers, and metal compounds such as magnesium hydroxide, aluminum hydroxide and zinc borate (4). 

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