Aluminium trihydroxide

Low, G.C., 1975. Agglomeration effects in aluminium trihydroxide precipitation. Ph.D. Dissertation, University of Queensland, Australia. 

Misra, C. and White, E.T., 1971. Kinetics of aluminium trihydroxide from seeded caustic aluminate solutions. American Institute of Chemical Engineers Symposium Series, 67(110), 53-65. 

Aluminium borohydride Aluminium chloride Aluminium chlorate Ammonium tetrachloroaluminate Aluminium fluoride Aluminium trihydroxide Aluminium ammonium sulphate Aluminium potassium sulphate Aluminium nitride Aluminium nitrate Sodium aluminate Aluminium sodium aluminate Aluminium phosphate Aluminium phosphide Aluminium borate Aluminium oxychloride Aluminium fluorosilicate Aluminium magnesium silicate Aluminium sulphate... 

The aim was to assess the feasibility of substitution with less hazardous flame retardants. They selected red phosphorus, ammonium polyphosphate and aluminium trihydroxide as the least environmentally problematic alternatives. Red phosphorus can technically be used in a variety of polymers to meet even the toughest fire safety standards, although it may network forall applications. ... 

N. Ristolainen, U. Hippi, J. Seppala, A. Nikanen, and J. Ruokolainen, Properties of polypropylene/aluminium trihydroxide composites containing nanosized organoclay, Polym. Eng. Sci., 2005, 45 1568-1575. 

Although various modifications of aluminium trihydroxide, Al(OH)3, have been described in the literature, there are only three common forms gibbsite (originally also called hydrargillite) bayerite and nordstrandite. Gibbsite is die best known and most abundant. It is the main constituent of North and South American bauxite and is obtained as an intermediate product (i.e. Bayer Hydrate ) in the Bayer process for the production of aluminium from bauxite. 

Some of the best-known examples of this type of reaction are the thermal decomposition of hydroxides to give active oxide-hydroxides and oxides (see Section 10.3.6). Another example is the calcination of a carbonate (e.g. CaC03). In fact, BET areas of up to 500 m2 g-1 can be produced by the calcination of an aluminium trihydroxide. But, unless the heat treatment is carefully regulated, as in controlled rate thermal analysis (CRTA), the pore structure of the active product tends to be highly heterogeneous (Rouquerol and Ganteaume, 1977). 

Aluminium hydroxides. Aluminium trihydroxide is known to have three modifications hydrargillite (gibbsite), bayerite and norstandite. Most widely used gibbsite is a natural mineral it can be also synthesized by... 

There are three polymorphs of aluminium trihydroxide gibbsite, bayerite and nordstrandite. The difference between the three polymorphs is in the stacking order... 

Gnyra, B., Jooste, R.F. and Brown, N. (1974) Polycrystallization of aluminium trihydroxide. Journal of Crystal Growth, 21, 141-145. 

Zinc-containing linseed oil-based poly(ester amide) resins with different loadings of zinc acetate were prepared by an in situ condensation polymerisation reaction between linseed oil fatty amide diol, phthaUc anhydride and zinc acetate (a divalent metal salt with different mole ratios) in the absence of any solvent (Fig. 5.3). Similarly, linseed oil based-poly(ester amide urethane)s with alumina, Zn and Cd were prepared in situ by the reaction of linseed oil-derived fatty amide diol, aluminium trihydroxide, divalent zinc/cadmium acetate and toluene-2,4/2,6-diisocyanate, using a minimal amount of solvent.Castor oil and soybean oil-based poly(ester amide) containing Cd and Zn were also prepared to obtain improved performance, including antimicrobial properties. ... 

Some fillers perform valuable specialist functions and some are discussed in other sections of this report. One example is aluminium trihydroxide (ATH), discussed under the heading of Flame Retardants and Smoke Suppressants, rather than Fillers. Carbon black has several roles, improving polymer conductivity, electrostatic dissipation and UV stabihsation. Antimony trioxide is a flame retardant synergist. 

Organotitanates, aluminates, zirconates and zircoaluminates can also act like silanes as adhesion promoters. They perform similar functions, but unlike silanes there is no need for water molecules to be eliminated. These other treatments bond the polymer to the filler surface by a chemical bond involving proton co-ordination, and they can also be used with fillers that are not receptive to silanes, such as calcium carbonate, carbon black and barium sulfate, as well as barium ferrite, magnesium hydroxide, aluminium trihydroxide, titanium dioxide, talc and the nanoclays. 

Metal hydroxides provide an important alternative to halogenated flame retardants. Aluminium trihydroxide, sometimes known as alumina trihydrate, is the most widely used of all FRs in plastics. Magnesium hydroxide is also finding increasing acceptance, and calcium hydroxide is being marketed as an additive for different reasons. 

Aluminium trihydroxide decomposes on heating at about 190 °C to form alumina and water, according to the eqnation ... 

An organic modified bentonite nanoclay called Nanofil has been developed for cable compoimds by Siid-Chemie. It enables less aluminium trihydroxide to be used in cable compounds because it contributes to flame retardancy. 

ATH aluminium trihydroxide (sometimes called aluminium trihydrate)... 

According to our method of thermochemical activation /lO/, one can also use aluminium trihydroxide to obtain the product with 4-,5- and 6-coordinated Al(III) ions, close in its properties to Jt-Al203 Dehydration via thermochemical activation is performed with the rates significantly greater than that of transformation of trihydroxide with a layered crystalline frame into the oxide of a crystal cubic structure. The latter is provided by the rapid heating of trihydroxide, mild temperature conditions of activation for a definite period of time, by the maintenance of the given partial pressure of water vapors, rapid cooling and calcination of the activation product. 

The thermal decomposition of gibbsite was chosen to illustrate the application of modem instrumental and computing techniques to preparative controlled reaction rate methods for making reproducible catalysts or catalyst supports of high surface area at atmospheric pressure. Gibbsite is one form of aluminium trihydroxide, Al(OH)3, the other being the mineral bayerite [6]. The thermal decomposition of gibbsite is complex, and is influenced both by crystallite size and water vapour pressure. Two processes, which may overly under certain conditions, have been identified [7] ... 

Materials/characteristic.s Some inorganic fillers. Nitrogen-donors melamine compounds. Antimony compounds with halogen donors. Halogenated containing chlorine, bromine. Halogen-free systems aluminium trihydroxide (ATH), magnesium hydroxide, zinc borate. Intumescent systems phosphorus compounds. 

Description Most widely used filler for plastics forms vary according to geographical source. Surface treatments greatly improve properties and controlled particle size makes functional fillers possible improved flow properties, low-profile anti-shrinkage, anti-blocking additives treatment with aluminium trihydroxide (ATH) gives some flame retardancy ... 

Reduction of flammability and smoke production when submitted to fire - flame retardant additives are used (e.g., antimony trioxide, phosphorus compounds, aluminium trihydroxide, magnesium hydroxide, zinc borates)... 

Metal hydroxides, in particular aluminium trihydroxide (ATH), which is a low-cost filler, and magnesium dihydroxide (MDH). The endothermic decomposition of Al(OH)3 occurs between 180 and 200°C and leads to the release of water and the formation of an insulating ceramic layer of alumina (AI2O3). The use of ATH also reduces the HRR peak aud the smoke production. Mg(OH)2 acts in a similar way but its endothermic degradation occurs at a higher temperature (over 300°C) and a protective layer of MgO is formed at the composite surface. 

Aluminium trihydroxide is often incorrectly called alumina trihydrate, but fortunately the abbreviation ATH serves for both. It is also known as Gibbsite or Nordstrandite or Hydrargilhte. Some 40-50 million tpa are manufactured from bauxite ores by extraction using sodium... 

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

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