Fiber benzoylation

Benzoylation treatment This treatment reduces the hydrophilic nature of fibers. Benzoyl chloride is typically reacted to introduce a benzoyl group (C HjC=0) onto the fiber. Like acetylation, prior to treatment with benzoyl chloride, a pretreatment with NaOH is common [22], The chemical reactions can be observed in Equations 9.6a and 9.6b. 

The effect of Fe(II) on grafting of 2-hydroxyethyl methacrylate onto polyester fibers in the presence of benzoyl peroxide was investigated [59]. It was found that increasing the iron ion concentration decreases the graft yield. This suggest that excess Fe(ll) ions participate in the generation of free radical species and the iron ions seem to contribute to the termination and, consequently, decrease the graft yield. 

About 8,000 metric tons of peroxides were consumed in 1972. This consumption was strongly stimulated by the rapid growth in reinforced plastics (Ref 23). The largest volume product is benzoyl peroxide which is used in polystyrene and polyester markets for such items as toys, automobiles, furniture, marine, transportation and mil requirements. Also, methyl ethyl ketone peroxide is used in large volumes to cure (as a catalyst) styrene-unsatur-ated polyester adhesive resins used in mil ammo adhesive applications, as well as in glass fiber reinforced plastic products such as boats, shower stalls, tub components, automobile bodies, sports equipment, etc. The monoperesters are growing slowly because of some substitution of the peroxydicarbonates and azo compds (Refs 8,9 23)... 

Durch Reduktion von 1,3,4-Oxadiazolen konnten bisher keine Dihydro-1,3,4-oxadiazole bzw. 1,3.4-Oxadiazolidine hergestellt werden, da hierbei Ringspaltung stattfinden kann. Die reduk-tive Spaltung von 2,5-Diphenyl-l,3,4-oxadiazol mit Natrium verlauft fiber ein Anion-Radikal unter Dimerisierung und Decarboxylierung zu 1.2-Bis-[benzoyl-hydrazono]-l,2-diphenyl-ethan (92% Schmp. 205-207°)696... 

The last of the direct methods for graft initiation in liquid phase presented in this review involves chemical additives. Either free radical or ionic initiators can be chosen. Benzoyl peroxide is reported for grafting styrene on Nylon fibers in methanol media (71,105-107), as well as vinyl acetate (106). Azoisobutyro-nitrile has been employed in systems where the graft monomer is styrene (71,106) or vinyl acetate (106). Redox systems involving hydrogen peroxide and monomers like styrene (106,108,109). vinyl acetate (106), acrylic acid (108,109), methyl... 

On the other hand, chemicals might be chosen as agents for generation of active centers in the polymeric backbone and grafting of monomer in the vapor phase. Ammonium persulfate and styrene (189), acrylic acid (190), butyl acrylate (191), potassium persulfate and n-butyl maleate or 2-ethyl hexyl acrylate (55,134) and ammonium ceric nitrate and methacrylic add (192) are examples of this method. Benzoyl peroxide deposited on polycaprolactam fibers initiates the grafting of styrene in vapor phase (193). 

Acylaminoanthraquinones. Acylation of amino anthraquinones with benzoic acid or benzoyl chloride, for example, affords vat dyes with satisfactory affinity to cellulose fibers. The simplest dyes of this type, 1,4- and 1,5-dibenzoylaminoanthra-quinones, are no longer important. Bridging linkages, such as the dicarboxylic acids oxalic or phthalic acid, permit coupling of two anthraquinone units three amino anthraquinones may be combined by use of a triazine, such as cyanuric chloride. 

Some dicyanate-containing compositions, which contain rubbers as flexibilizing components, were described in the preceding chapters. There were also patent applications made, where dicyanates were claimed as additives in typical rubber mixtures. In such mixtures, butadiene-acrylonitrile rubber is used. The main components of such binders are nitrile rubber, BPA/DC and methylethylketone. They contain, moreover, Zn octoate and Fe203 [144] or ZnO and sulfur [145]. Isoprene-acryloni-trile rubber, BPA/DC prepolymer, Zn octoate, DABCO and benzoyl peroxide were dissolved in a methylethylketone-dimethylformamide mixture. Glass fiber was impregnated with the obtained solution [146]. 

Materials. The dispersed phase of the dispersions contained, by weight 98.07% acrylic polymer beads, 0.8% benzoyl peroxide (98% active), 1% red acetate fibers, 0.03% red pigments, and 0.1% Ti02 pigment. The acrylic polymer beads were a 50/50 wt/wt blend of two suspension polymerized poly (methyl methacrylate) polymers with solution molecular weights of 160,000 and 950,000. Additives to the dispersed phase were those described above. The polymers were each reduced 1 vol % on the total dispersion volume to compensate for the additives. 

In a Pasteur pipette loosely place a very small piece of cotton followed by 2.5 g of alumina. Add to the top of the pipette 1.5 mL of styrene and collect 1 mL in a disposable 10 x 75-mm test tube. Add to the tube 50 mg of benzoyl peroxide and a thermometer and heat the tube over a hot sand bath. When the temperature reaches about 135°C polymerization begins and, since it is an exothermic process, the temperature rises. Keep the reaction under control by cautious heating. The temperature rises, perhaps to 180°C, well above the boiling point of styrene (145°C) the viscosity also increases. Pull the thermometer from the melt from time to time to form fibers when a cool fiber is found to be brittle remove the thermometer. A boiling stick can be added to the tube and the polymer allowed to cool. It can then be removed from the tube or the tube can be broken from the polymer. Should the polymer be sticky the polymerization can be completed in an oven overnight at a temperature of about 85°C. 

Acylated starch can be copolymerized to yield materials for films, lacquers, and fibers.2111 Starch acetate copolymerized with epichlorohydrin was extruded to give cold-water swelling products with a high degree of friability.2112 Epichlorohydrin-crosslinked starch has been acylated with 2,3-di-O-benzoyl-L-threaric anhydride.2113 The reaction proceeded either in /V,/V-dimethy 11 ormam ide or in toluene, and the non-crosslinked product has also been reported.2114... 

Befindet sich die funktionelle Gruppe in 3-Stellung, so fiihrt die Hydrierung fiber Palladium haufig unter Erhaltung des Substituenten zu 1,4,5,6-Tetrahydro-pyridinen13, vgi. aber 14 w rendfiber Platin(IV)-oxidz. B. aus l-Methyl-3-benzoyl-pyridinium-bromid... 

Benzoyl peroxide should be stored in a cool and well-ventilated area, isolated from other chemicals and free of heating and electrical installations. Dry compound may be shipped in polyethylene-lined paper bags or fiber containers packed in wooden boxes or fiberboards. Metal drums or barrels with polyethylene liners are recommended. 

Application of this photocyclization to polymers, such as 4, should afford an effident photochemical route to the synthesis of ordered polymer systems based upon a phenyl substituted benzofuran repeat unit (Scheme II). Due to a fair degree of molecular flexibility, photopolymer 4 should be soluble in a variety of organic solvents. Photocyclization of 4 could then be carried out either in solution or the solid state (films, fibers, or coatings). This paper describes the photochemistry of low molecular w/eight formulations of 4 (n- 1,5,10) and that of an appropriate model compound, 1,4-bis(2-benzyioxy-benzoyl)benzene, 4a. 

Example 2.2 Unsaturated polyester resins, which are used as the matrix component of glass-fiber composites, may be obtained by the copolymerization of maleic anhydride and diethylene glycol. The low-molecular-weight product is soluble in styrene. Describe, with the aid of equations, the possible structures of the prepolymer and that of the polymer resulting from benzoyl peroxide-initiated polymerization of a solution of the prepolymer in styrene. 

Native cellulose are commonly modified by physical, chemical, enzymic, or genetic means in order to obtain specific functional properties, and to improve some of the inherent properties that limit their utility in certain application. Physical/surface modification of cellulose are performed in order to clean the fiber surface, chemically modify the surface, stop the moisture absorption process, and increase the surface roughness. " Among the various pretreatment techniques, silylation, mercerization, peroxide, benzoylation, graft copolymerization, and bacterial cellulose treatment are the best methods for surface modification of natural fibers. 

Various vinyl monomers were grafted onto nylon fibers by using benzoyl peroxide in the presence of inorganic salts such as sodium or potassium chloride and sodium or potassium sulfate[42,43]. The vinyl monomers include acrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate, styrene, acrylonitrile, and mixtures of these monomers. Sakurada. et al. [43,44] investigated grafting eflBciency for various radical initiators. They foimd that pero disulfate systems... 

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