Hydrogen peroxide viscosity

Because the reaction takes place in the Hquid, the amount of Hquid held in the contacting vessel is important, as are the Hquid physical properties such as viscosity, density, and surface tension. These properties affect gas bubble size and therefore phase boundary area and diffusion properties for rate considerations. Chemically, the oxidation rate is also dependent on the concentration of the anthrahydroquinone, the actual oxygen concentration in the Hquid, and the system temperature (64). The oxidation reaction is also exothermic, releasing the remaining 45% of the heat of formation from the elements. Temperature can be controUed by the various options described under hydrogenation. Added heat release can result from decomposition of hydrogen peroxide or direct reaction of H2O2 and hydroquinone (HQ) at a catalytic site (eq. 19). 

In fastness to peroxide bleaching, ISO 10S-N02, the specimen is immersed ia a standard bleaching solution containing hydrogen peroxide (or sodium peroxide for viscose) where the composition of the bleaching Hquor is dependent on the fibers used ia the test specimen as are the pH and time of exposure (1—2 h). The objective of the test is to assess the colorfastness usiag typical bulk bleaching conditions for the fiber under test. 

Cotton linters and viscose grade wood pulp were grafted with acrylamide using the xanthate method. The effects of monomer concentration, reaction time, hydrogen peroxide concentration, reaction temperature, and liquor ratio on the grafting process were studied. Optimum conditions for the grafting reaction were established [26]. 

Compositions and functions of typical commercial products in the 2-alkyl-l-(2-hydroxyethyl)-2-imidazolines series are given in Table 29. 2-Alkyl-l-(2-hydroxyethyl)-2-imidazolines are used in hydrocarbon and aqueous systems as antistatic agents, corrosion inhibitors, detergents, emulsifiers, softeners, and viscosity builders. They are prepared by heating the salt of a carboxylic acid with (2-hydroxyethyl)ethylenediamine at 150—160°C to form a substituted amide 1 mol water is eliminated to form the substituted imidazoline with further heating at 180—200°C. Substituted imidazolines yield three series of cationic surfactants by ethoxylation to form more hydrophilic products quatemization with benzyl chloride, dimethyl sulfate, and other alkyl halides and oxidation with hydrogen peroxide to amine oxides. 

The first application of the ferrous ion-hydrogen peroxide initiation for polymerizing vinyl monomers on and into cellulose fibers has been reported by Landeias and Whewell (41) in three successive papers. They are apparently the first who applied the "anchored catalyst technique, which other people have termed "in situ polymerization to cellulose grafting. The authors internally deposited methyl methacrylate, acrylonitrile, styrene, methyl vinyl ketone and methacrylamide in amounts between 10 and 80%. No attempt had been made to determine if actual grafting had occurred. In 1961 Richards (42) studied this question in great detail. Products obtained by polymerization of acrylonitrile and of styrene in viscose rayon were acetylated. Fractionation of... 

Figure 1.20 Viscosity range of hydrogen peroxide-water mixtures.

Properties (pure anhydrous) density of solid, 1.71 g/cc, density of liquid 1.450 g/cc at 20C, viscosity, liquid 1.245 cP, surface tension 80.4 dynes/cm at 20C, fp -0.41C, bp 150.2C. Soluble in water and alcohol. (Solutions) pure hydrogen peroxide solutions, completely free from contamination, are highly stable a low percentage of an inhibitor such as acetanilide or sodium stannate, is usually added to counteract the catalytic effect of traces of impurities such as iron, copper, and other heavy metals. A relatively stable sample of hydrogen peroxide typically, decomposes at the rate of approximately 0.5% per year at room temperature. 

Diacetate/viscose blends have been used in dresswear, shirting and under-wear. These blends may be bleached with hydrogen peroxide or sodium hypochlorite, preferably the latter. 

Pseudoplastic and thixotropic liquid detergents as emulsions are the subjects of U.S. Patent 5,851,979. Equilibrium viscosity values measured using a Brookfield viscometer with Spindle no. 2 at 20°C are cited at 12, 30, and 60 r/min. For one example containing hydrogen peroxide, the viscosity is 1020, 400, and 220 cP at 12, 30, and 60 r/min, respectively. Pseudoplasticity is clearly evident, as the viscosity decreases with increasing rotational speed. 

Dahl, T., He, G-X., and G. Samuels. 1998. Effect of hydrogen peroxide on the viscosity of a hydroxy-ethylcellulose-based gel. Pharm. Res. 15 1137-1140. 

Reduction of acetals with NaBH4 was reported,1369 but no applications of the products were given. Crosslinking of starch acetals with epichlorohydrin and similar compounds was also described.1370 A urea-formaldehyde-starch copolymer reacted with hydrogen peroxide and Cu(II) catalysts, thereby producing a starch solution with improved stability of viscosity.1371... 

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