Borates hydrated

Disodium Octaborate Tetrahydrate. The composition of a commercially available sodium borate hydrate, 66.3 wt % B203, POLYBOR (64), corresponds quite closely to that of a hypothetical compound, disodium octaborate tetrahydrate, Na2Bg013 TH O or Na O 4-B203 4H20. This product dissolves rapidly in water without the temperature decrease, which occurs when the crystalline borates dissolve, and easily forms viscous supersaturated solutions at elevated temperatures. The solution pH decreases as the concentration increases (Table 10). The solubility of the product is shown compared with that of borax (33) ... 

The only definite borate hydrates of cobalt are the CoO - 3B203 - 8H20 and CoO 3B203 10H2O compounds. The octahydrate is prepared by evaporation of acetic acid from cobalt acetate-boric acid mixtures, or by mixing aqueous solutions of cobalt chloride, borax, and boric acid (206). The 1 3 7.5 borate can form as a solid solution and, in the presence of 3% boric acid, affords the decahydrate (117). The crystal structure determination of this 1 3 10 compound shows it to possess the hexaborate ion (380). The IR spectra (402) and thermal decomposition (396) of these compounds have been determined. 

Attempts to crystallize cation-water host lattices analogous to the per-alkyl ammonium salt hydrates, e.g., tetraalkyl borate hydrates, were unsuccessful [432]. 

Smoke suppressants are also important additives in fire retardancy. Resulting from an incomplete combustion, opaque smoke may evolve that leads to panic and slow the rescuers progress. Additives, such as antimony oxides, metal borates, hydrates of magnesium or aluminium and magnesium oxychlorides, are used as fillers and flame retardants, but they are also good smoke reducers. 

RCI3 solution reacts with horax solution at pH 6.5-6.9 to form a borate hydrate precipitate. Analysis of the dried powder indicated the composition R(B02)3 AJH2O ( = 4 or 6) (Vasilev and Serehrennikov, 1964 Pajakoflf, 1969). 

Copper Tertiary oxides Copper borate hydrate... 

Zinc borate hydrate is another hydrated filler for rubber, which imparts flame retardancy properties. A specific zinc borate hydrate with a composition of ZZnO-SBjOa S.SHjO is a form commonly used and found effective for flame retardancy. 

Zinc borate hydrate is produced as follows in Figure 11.52. 

Zinc borate hydrate is used in the rubber industry as a flame-retardant additive. It works by promoting the formation and stabilization of a char, which helps cut off the fuel source to the flame. The water of hydration also helps impart flame retardancy. 

Other flame retardants are available that can substitute for zinc borate hydrate however, the compound must be reformulated to meet other product physical property requirements. 

Borax is usually mined from salt lakes as sodium borate hydrate. 

Borax is used to produce boric acid, which is used to make zinc borate hydrate (a flame-retardant additive used in rubber compounding). 

Boric acid is reacted directly with zinc oxide to produce zinc borate hydrate, a commonly used flame retardant. 

Sc(Br03)3 -6H20 can be synthesized similarly to the other rare earth borate hydrates. Thermal decomposition of eimeahydrates occurs via intermediate phases. Tetrahydrates have been determined for La---Eu, trihydrates for Dy - Tm, Y, and dihydrates for La---Tb compounds (James and Langelier, 1909 Petru and Dusek, 1968 Yakunina et al., 1969a, 1970). 

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