Ammonia-hydrogen peroxide system

Particularly when PVP is considered for application as a blood plasma extender, trace amounts of extraneous materials may be objectionable. The ammonia-hydrogen peroxide system discussed above may give rise to acetaldehyde-ammonia complexes that may be capable of further condensation reactions. Hydrogen peroxide may also oxidize acetaldehyde to acetic acid. The molecular weight distribution of the polymer also appears to be critical in blood plasma extenders. 

The bis-hydroxylamine adduct [Fe (tpp)(NH20H)2] is stable at low temperatures, but decomposes to [Fe(tpp)(NO)] at room temperature. [Fe(porphyrin)(NO)] complexes can undergo one-and two-electron reduction the nature of the one-electron reduction product has been established by visible and resonance Raman spectroscopy. Reduction of [Fe(porphyrin)(NO)] complexes in the presence of phenols provides model systems for nitrite reductase conversion of coordinated nitrosyl to ammonia (assimilatory nitrite reduction), while further relevant information is available from the chemistry of [Fe (porphyrin)(N03)]. Iron porphyrin complexes with up to eight nitro substituents have been prepared and shown to catalyze oxidation of hydrocarbons by hydrogen peroxide and the hydroxylation of alkoxybenzenes. ... 

HA can be produced by catalytic oxidation of ammonia with hydrogen peroxide or by catalytic reduction of nitrates with hydrogen . Analogously, oxidative and reductive enzymic pathways in which HA is produced from either ammonia or nitrate have been identified in a variety of biological systems. 

Other most successful durable treatment is based on tetrakis (hydroxymethyl) phosphonium derivatives. Very well-known brand marketed as Proban CC (Rhodia, previously Albright Wilson) involves padding of tetrakis (hydroxymethyl) phosphonium chloride (THPC) urea solution onto the cotton fabric, curing with ammonia in a specially designed reactor to generate a highly cross-linked three-dimensional polymer network. The fabric is then treated with hydrogen peroxide, which converts P3+ to the P5+ state. The reactions are shown in Scheme 24.2. Other similar commercial product is Thor s Aflammit P. In literature many combinations of tetrakis (hydroxymethyl) phosphonium derivatives with other salts have been reported,50 but the most successful so far has been the THPC-urea-NH3 system discussed earlier. 

The formation of an isothiazole ring from the thiophene system (5) is of interest. Probably ammonia breaks the sulfur-carbonyl bond and then adds to the second carbonyl group, giving an imine (8), which is then oxidized by the hydrogen peroxide. A number of similar rearrangements and interconversions of isothiazole, thiophene, and dithiole systems are known and will be discussed later (Section II,C,3). 

A variation on the THPC-urea system was developed to produce finishes with less stiffness and fibre damage (Proban process). A precondensate is prepared by the careful reaction of THPC with urea. This precondensate is padded onto the fabric and the fabric is dried to a specific moisture content ( 15 %). The fabric is then exposed to ammonia vapours in a special reaction chamber, followed by oxidation with hydrogen peroxide (Fig. 8.13). The polymer that forms is primarily located in the lumen of the cotton fibre. The final finish provides durable flame retardancy to cotton with much improved fabric properties. It is important to note... 

The ATOCHEM process utilizes the reaction among ketone, ammonia, and hydrogen peroxide. The process is also called the Ugine Kuhlmann process. The process obtains azine in high yields via the hydrogen peroxide oxidation of ketone-ammonia system in the presence of nitrile (RCN). This synthesis route bypasses chlorination. 

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