Antimony-oxygen system

AntimonyCni), surface formation, 30 113 Antimony-oxygen system, 30 101 Apolar solute, 32 432... 

It is now possible to consider the ternary tin-antimony-oxygen system. It would be reasonable to expect that multiphase systems would predominate in antimony rich materials although there is little information about the solubility of tin in antimony oxide. Since the metal-oxygen bond lengths in tin(IV) and antimony(V) and (III) oxides are all similar 26, 29), it is reasonable to expect that mixed oxide formation by coprecipitation is feasible and would involve the replacement by antimony of tin in the tin(IV) oxide... 

In order to establish the identity of the trimethylcarbonium ion, the t-butyl fluoride-antimony pentafluoride system was investigated. It was found that when the vapour of t-butyl fluoride was passed over the surface of purifled liquid antimony pentafluoride (with exclusion of moisture and oxygen) a stable complex layer is formed on the top of the antimony pentafluoride. When this layer was separated and its proton magnetic resonance investigated (see subsequent discussion) the spectrum was found to be identical with that of the least-shielded species formed by decarbonylation of the t-butyloxocarbonium salt... 

AS A FLAME RETARDANT. The zinc borate is an efficient synergist of organic halogen sources. In certain halogen-containing systems such as unsaturated polyester, epoxy (3), and rigid PVC, the zinc borate alone can outperform antimony oxide as shown by the Oxygen Index and UL-94 tests (Fig. 3, 4, and 5). 

In other halogen-containing systems, such as flexible PVC and polyolefins, it is preferable to use the zinc borate in conjunction with antimony oxide for maximum performance. In flexible PVC, for example, the zinc borate alone is not very effective in the Oxygen Index test (Fig. 6), but a combination of the zinc borate and antimony oxide (1 1 ratio) outperforms equal weight of antimony oxide at a total loading of more than 10 phr (4). In the presence of alumina trihydrate (ATH), the beneficial effect of using a combination of the zinc borate and antimony oxide is dramatically increased (Fig. 7). 

We previously reported that brominated aromatic phosphate esters are highly effective flame retardants for polymers containing oxygen such as polycarbonates and polyesters (9). Data were reported for use of this phosphate ester in polycarbonates, polyesters and blends. In some polymer systems, antimony oxide or sodium antimonate could be deleted. This paper is a continuation of that work and expands into polycarbonate alloys with polybutylene terephthalate (PBT), polyethylene terephthalate (PET) and acrylonitrile-butadiene-styrene (ABS). 

Acrolein and Acrylic Acid. Acrolein and acrylic acid are manufactured by the direct catalytic air oxidation of propylene. In a related process called ammoxida-tion, heterogeneous oxidation of propylene by oxygen in the presence of ammonia yields acrylonitrile (see Section 9.5.3). Similar catalysts based mainly on metal oxides of Mo and Sb are used in all three transformations. A wide array of single-phase systems such as bismuth molybdate or uranyl antimonate and multicomponent catalysts, such as iron oxide-antimony oxide or bismuth oxide-molybdenum oxide with other metal ions (Ce, Co, Ni), may be employed.939 The first commercial process to produce acrolein through the oxidation of propylene, however, was developed by Shell applying cuprous oxide on Si-C catalyst in the presence of I2 promoter. 

The formation of rutile mixed phases in the system Ti-Ni-Sb-0 is described in detail in [3.92], When nickel ions are to be included in the pigment and antimony trioxide is used to provide the antimony ions, oxygen must be present to ensure that nickel and antimony occupy the titanium sites in the lattice. If oxygen is excluded, only small amounts of nickel and antimony are taken up in solid solution, and no useful products are formed. The presence of oxidizing agents (e.g., nitrates) is necessary for the production of antimony-containing mixed metal oxide pigments. 

The crystal structure of /i-oxo-bis[tris(p-chlorophenyl)(l,l,l-trifluoro-2,4-pen-tanedionato-0,0 )antimony(V)] 1/2 chloroform has been determined375. The compound crystallizes in triclinic system, space group PI. The binuclear Sb-complex consists of two distorted octahedra joined by an O atom which is situated at inversion centre the Sb-O-Sb bridge is linear. This seems to be the first example of a linear Sb-O-Sb linkage. The bridged oxygen and one of the oxygens of/3-diketone occupy trans-positions. The/3-diketonate forms two distinct Sb-0 bonds ... 

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