Anhydrides, containing phosphorus

VPO catalyst, they are assumed to be V2Ok units made up of pairs of distorted edge-sharing V05 square pyramids. The assumption of these active sites, especially for the VPO catalyst, was discussed in detail in Ref. 56, in view of the fact that the most selective VPO catalyst for butane oxidation to maleic anhydride contained a slight excess of phosphorus over the stoichiometric ratio for vanadyl pyrophosphate, the phosphorus was concentrated on the surface (57-61), and the average vanadium valence of the catalyst under reaction conditions was about 4.1 (57, 58). 

Terphenyl.8, 68 To a stirred solution of 10 g. of diacetyl-1,4-phenylenediamine in a mixture of 150 cc. of glacial acetic acid and 75 cc. of acetic anhydride containing 12 g. of anhydrous potassium acetate and 1 g. of phosphorus pentoxide at 8° is added dropwise a solution of 8 g. of nitrosyl chloride in acetic anhydride. The mixture is poured onto ice and water, and the yellow Jw s-nitrosoacetyl-1,4-phenylenediamine is filtered and dried yield, 11.4 g. m.p. 124° dec. 

Flame Retardants. Flame retardance can be built into the epoxy resin by use of tetrabromobisphenol A or anhydride curing agents containing phosphorus or halogen. It can also be helped by nonreactive additives such as alumina trihydrate or organo-halogens + antimony oxide. 

In an attempt to improve thermal stability even further a series of poly-anhydride-imides have been prepared containing phosphorus. While such polymers had good hydrolytic stability, they had little heat resistance and poor flame retardency. Several papers have appeared on the synthesis of polyesteri-mides. Photosensitive polyimides have also been prepared. " ... 

Those permanently fixed in polymer structures, also called reactive types, such as tetrabromodienes, pentabromophenol, hexabromophthalic anhydrides, polyols containing phosphorus, and halides. They are used mainly for polyesters, polyurethanes, and epoxy resins. 

The first fire retardant polyester containing a reactive fire retardant monomer was introduced by the Hooker Electrochemical Corporation in the early 1950 s containing chlorendic acid as the reactive monomer (6). This pioneering development rapidly led to the introduction of variety of reactive halogen and phosphorus containing monomers, such as tetrabromophthalic anhydride, chlorostyrene and tetrabromobisphenol A, which found application in a wide variety of condensation polymer systems. 

Nitrolysis reactions employing l,3,5-trisubstituted-l,3,5-triazacyclohexanes have been explored as alternative routes to RDX. Some of the results are illustrated in Table 5.4 and show the difference in the efficiency of the three nitrolysis agents used, namely, absolute nitric acid, phosphorus pentoxide-nitric acid and trifluoroacetic anhydride-nitric acid. The acetamide derivative (81) (TRAT) undergoes incomplete nitrolysis on treatment with absolute nitric acid and trifluoroacetic anhydride-nitric acid to give a crude product containing some l-acetyl-3,5-dinitro-1,3,5-triazacyclohexane (TAX) (82) (Table 5.4, Entry 1) the latter can be preferentially formed in 93 % by suitably modifying the reaction conditions. Interestingly, the nitrolysis of... 

In a well-ventilated hood, behind an explosion shield, to a finely divided suspension of 2.6 gm (0.01 mole) of fumardianilide in 90 ml of glacial acetic acid, 30 ml of acetic anhydride, and also containing 8 gm of freshly fused potassium acetate and 2 gm of phosphorus pentoxide, cooled to +7°C is added, slowly, with vigorous stirring, 25 ml of a 20 % solution of nitrosyl chloride (5 gm of nitrosyl chloride, 0.08 mole) in acetic anhydride. After the addition has been completed, stirring is continued for 2 hr while the reaction temperature is maintained between 7° and 12°C. During this period, much of the suspended material dissolves. 

UREA-AMMONIUM ORTHOPHOSPHATE. A fertilizer developed especially for food-deficient regions, particularly rice-dependent areas. Several grades contain all three primary plant nutrients (nitrogen, phosphorus, and potassium). Contains up to 60% nitrogen, phosphoric anhydride and potassium oxide. 

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