Magnesium borates structures

Infrared spectroscopy is the favored technique for characterizing borates, and several compilations of data have been made (171, 333,417, 423,431,432). The intense absorption at about 970 cm-1 is characteristic of tetrahedrally coordinated boron, as measured for the magnesium borates MgO B203 nH20 (153), and bands at 700 to 900 and 1200 to 1500 cm-1 can correspond to triangular boron coordination. Absorptions in the region 400 to 700 cm-1 have been attributed to chain structures (423). 

Structural reorganizations [126] during the thermal decompositions of hydrated borates in general, and of calcium borate (pandermite) and potassium magnesium borate in particular are complex, proceeding through step-by-step processes. The parent structure is gradually transformed into more stable forms by apparently the... 

Zinc borate can also change the oxidative decomposition pathway of halogen-free polymers. It is not completely clear if this is happening because of an inhibition effect of boron oxides toward the oxidation of hydrocarbons or the oxidation of graphite structures in the char, or is due purely to the formation of a protective sintered layer. In combination with ATH, zinc borate creates a porous ceramiclike residue, which has much better insulative properties than those of pure anhydrous alumina. It was shown that zinc borate accelerates dehydration of magnesium hydroxide and creates a ceramiclike structure with dehydrated MgO. 

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