Peroxide with

The Sn-C bond can be cleaved with hydrogen peroxide44-63 or peroxyacids.64 The reactions take place with retention of configuration, and presumably involve a nucleophilic rearrangement, for example equation 5-50.44 Ozonolysis has been used on a few occasions (e.g. equation 5-51),65 and also oxygen in the presence of a transition metal catalyst.66 

The term fluorous is used to indicate than an alkyl group, or a domain in an alkyl group, contains CF rather than CH bonds. We follow the convention that that a wholly fluorinated alkyl group is given the symbol Rf. 

A lot of attention has been paid recently, particularly by D.P. Curran s group,69 to the use of fluorous organotin compounds in organic synthesis, with the aim of simplifying 

Mokhtar-Jamai and M. Gielen, Bull. Soc. Chim. France, 1972,9B, 208. 

Prager, K. H. Dupree, and W. Muller-Warmuth, Z. Phys.B Condens. Matter, 

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Hydrogen Peroxide Analysis. Luminol has been used for hydrogen peroxide analysis at concentrations as low as 10 M using the cobalt(III) triethanolamine complex (280) or ferricyanide (281) as promoter. With the latter, chemiluminescence is linear with peroxide concentration from... 

Gross-Linking. A variety of PE resins, after their synthesis, can be modified by cross-linking with peroxides, hydrolysis of silane-grafted polymers, ionic bonding of chain carboxyl groups (ionomers), chlorination, graft copolymerization, hydrolysis of vinyl acetate copolymers, and other reactions. 

DiaHyl phthalate copolymerizes at 80°C with peroxide catalyst and small amounts of long chain vinyl monomers including vinyl laurate, dioctyl fumarate, lauryl methacrylate, and stearyl methacrylate (43). The products show increased elongations but reduced tensile strengths. 

Telomerization. Polymerization of DAP is accelerated by telogens such as CBr, which are more effective chain-transfer agents than the monomer itself (65) gelation is delayed. The telomers are more readily cured in uv than DAP prepolymers. In telomerizations with CCl with peroxide initiator, at a DAP/CCl ratio of 20, the polymer recovered at low conversion has a DP of 12 (66). 

The second process involves reaction of propylene with peroxides, as in the Oxirane process (97), in which either isobutane or ethylbenzene is oxidized to form a hydroperoxide. 

Antioxidants. The 1,2-dihydroquinolines have been used in a variety of ways as antioxidants (qv). For example, l,2-dihydro-2,2,4-trimethylquinoline along with its 6-decyl [81045-48-9] and 6-ethoxy [91-53-2] derivatives have been used as antio2onants (qv) and stabilizers (68). A polymer [26780-96-1] of l,2-dihydro-2,2,4-trimethylquinoline is used in resins, copolymers, lubricant oils, and synthetic fibers (69). These same compounds react with aldehydes and the products are useful as food antioxidants (70). A cross-linked polyethylene prepared with peroxides and other monomers in the presence of l,2-dihydro-6-ethoxyquinoline produces polymers with a chemically bonded antioxidant (71). 

Coagents ate often used with peroxides to increase the state of cure. Some coagents, such as polybutadiene or multifimctional methacrylates, are used at high levels to form polymer grafts or interpenetrating networks. Other coagents such as triaHyl cyanurate, triaHyl trimelHtate, and y /i -phenjiene bismaleimide are used at low levels to reduce the tendency of the polymer to degrade by chain scission. 

Vinyl Acetate—Ethylene Copolymers. In these random copolymers, the ratio of ethylene to vinyl acetate (EVA) is varied from 30—60%. As the vinyl acetate content increases, the oil and heat resistance increases. With higher ethylene content the physical strength, tensile, and tear increases. The polymers are cured with peroxide. The main properties of these elastomers include heat resistance, moderate oil and solvent resistance, low compression set, good weather resistance, high damping, exceUent o2one resistance, and they can be easily colored (see Vinyl polymers, poly(VINYL acetate)). 

Owing to the light and air sensitivity of the carotenoids and retinoids, sample handling is a critical issue. It is recommended to conduct extraction of these materials with peroxide-free solvents, to store biological samples at —70° C under argon and in the dark, to perform the analysis under yellow light, and to use reference compounds of high purity (57). 

Coacrete can also be made water-repeUent by the polymerisation of vinyl monomers on the surface (85). Polymerisation can be iaitiated with peroxides, and polyfunctional methacrjiates can be used as crosslinking agents. These treatments have a tendency to produce changes ia color and gloss. 

Cyanate can be further oxidized by HOCl to nitrogen and bicarbonate along with small amounts of N2O and NCl. Hypochlorous acid reacts with peroxide with evolution of oxygen by the postulated intermediate formation of peroxyhypochlorous acid (99). 

The conjugated diene butyl chain can be cross-linked with peroxide or radiation exposure. Free radicals also ate used to graft cute with vinyl monomers, eg, methacryhc acid or styrene, which lead to transparent mbbet exhibiting a T of about —59 C. 

Curing. Carboxyl cure sites are incorporated in the ethylene—acryhc terpolymer to permit cross-linking with primary diamines (1,7). Guanidines are added to accelerate the cure. Peroxides may also be used as curing agents in the terpolymer, but generally give inferior properties to vulcanizates based on diamine systems (8). Dipolymers are cured only with peroxides. 

The most widely used plasticizers are paraffinic oils. Por appHcations that specify high use temperatures, or for peroxide cures, paraffinic oils of low volatihty are definitely recommended. However, since paraffinic oils exude at low temperatures from EPDM vulcanizates, or from high ethylene EPDMs, they are often blended with naphthenic oils. On the other hand, naphthenic oils interfere with peroxide cures. Aromatic oils reduce the mechanical properties of vulcanizates, and they also interfere with peroxide cures. Therefore, they are not recommended for EPM/EPDM. 

Orotic acid undergoes 5-nitration, 5-bromination in hydrobromic acid with peroxide, 5,5-dibromination following decarboxylation in bromine water, esterification, methylation (rather complicated), conversion into its acid chloride (containing some anhydride) by treatment with thionyl chloride, and conversion into 2,6-dichloropyrimidine-4-carboxylic acid by phosphoryl chloride (62HC(16)422). 

Ethylene has also been copolymerised with a number of non-olefinic monomers and of the copolymers produced those with vinyl acetate have so far proved the most significant commercially . The presence of vinyl acetate residues in the chain reduces the polymer regularity and hence by the vinyl acetate content the amount of crystallinity may be controlled. Copolymers based on 45% vinyl acetate are rubbery and may be vulcanised with peroxides. They are commercially available (Levapren). Copolymers with about 30% vinyl acetate residues (Elvax-Du Pont) are flexible resins soluble in toluene and benezene at room temperature and with a tensile strength of about lOOOlbf/in (6.9 MPa) and a density of about 0.95 g/cm. Their main uses are as wax additives and as adhesive ingredients. 

More recently, in 1975, Du Pont introduced a terpolymer (Vamac) based on ethylene, methyl acrylate and a third monomer of undisclosed composition which contained a carboxylic acid group to provide a cure site for use with peroxides or amines. Both types of rubber exhibit good heat, oxygen and ozone resistance. 

Silicone rubbers are normally cured with peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide and t-butyl perbenzoate being used for the dimethyl-silicones in quantities of 0.5-3%. These materials are stable in the compounds for several months at room temperature but will start to cure at about 70°C. 

Chemical Reactivity - Reactivity with Water No reaction Reactivity with Common Materials No reactions Stability During Transport Explosive decomposition when contaminated with peroxides formed by reaction with air Neutralizing Agents for Acids and Caustics Not pertinent Polymerization Polymerization inhibited when stabilizer is used Inhibitor of Polymerization tert-Butylcatehol (0.01 -0.02%). 

It results from the oxidation of sabinenic acid with peroxide of lead, sabinenic acid itself being an oxidation product of the terpene sabinene. It is a liquid having the following characters —... 

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