Aluminium hydroxide suppressant

Finely divided magnesium or aluminium hydroxides (or a 3 1 combination) are currently the best smoke suppressants. They also neutralise the acidic vapours produced from halogen-containing flame inhibiters. The more finely divide they are the more efficient they become. 

Antimony trioxide and chlorinated paraffinic derivatives are common materials used as fire retardants, as are intumescent zinc (or calcium) borate, aluminium hydroxide and magnesium hydroxide. These inorganic materials, used as bulk fillers, act to reduce the fire hazard. Halogenated materials release chlorine, which then combines with the antimony trioxide to form the trichloride, which is a flame suppressant. 

Consideration is given to the influence of combinations of zinc hydroxystannate (ZHS) with hydrated fillers, on the fire properties of plasticised PVC and polychloroprene. It is shown that magnesium and aluminium hydroxides specially coated with ZHS, confer significantly increased combustion resistance and lower levels of smoke evolution to these polymers. This permits large reductions to additive loading relative to unmodified filler, without sacrificing flame retardant or smoke suppressant performance. 10 refs. 

Specially coated magnesium and aluminium hydroxides confer significantly increased combustion resistance and lower levels of smoke evolution, permitting large reductions in additive loading, without sacrificing flame retardant or smoke suppressant performance. 

Seawater predominantly consists of about 3.5% of sodium chloride (NaCl) and many other ions. Chloride ions are very strong and could easily penetrate the passive film Thus, dissolution of the aluminium substrate occurs and results in corrosion. The adsorption of the corrosion inhibitor competes with anions such as chloride. By assuming that the corrosion inhibitor molecules preferentially react with Al - to form a precipitate of salt or complex on the surface of the aluminum substrate, the anodic and cathodic processes subsequently suppressed by inhibitor molecules. Thus, this result suggests that the protective film that was formed comprise aluminium hydroxide, oxide and salts or complexes of the corrosion inhibitor anions. 

The objective of the synthesis would be to maximise the first reaction (leading to ferrlslllcates) and suppress the formation of hydroxides of iron by the latter reaction by operating at low pH, using aluminium free source of Si and adjusting the reaction conditions to maximise the concentration of monomeric/short chain silicate species. Usually the... 

Also the thermo-oxidative stability of the deactivated polymer is excellent. At the present time, hydroxides and partially dehydrated hydroxides of amphoteric metals, especially of aluminium, are applied as additives suppressing the flammability of polymers. 

Keywords alumina trihydrate (aluminium trihydroxide), magnesium hydroxide, calcium hydroxide, antimony trioxides, oxides of zinc, tin, molybdenum, iron, smoke suppression. 

Among the metallic hydroxide flame retardants, aluminium trihydrate, A1(0H)3 or magnesium hydroxide Mg(OH)2 are popular flame retardants and smoke suppressants (8). 

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