T-butyl perbenzoate

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. 

An example of this reaction is the reaction of cyclohexene with t-butyl perbenzoate, which is mediated by Cu(I). " The initial step is the reductive cleavage of the perester. The t-butoxy radical then abstracts hydrogen from cyclohexene to give an allylic radical. The radical is oxidized by Cu(II) to the carbocation, which captures benzoate ion. The net effect is an allylic oxidation. 

By reaction of 3-thienyllithium with magnesium bromide, the Grignard reagent, free from entrainment Grignard reagent, was obtained,- which is useful for the preparation of 3-acetothiophene by reaction with acetic anhydride at —70 0 and for the preparation of 3-t-butoxythiophene through reaction with t-butyl perbenzoate. It is the opinion of the present author that most 3-substituted thiophenes are prepared more conveniently from 3-thienyllithium than from 3-thenyl bromide. The latter method, however, is superior if the introduction of the 3-thenyl group is desired. 

These conditions are identical to those required for the homopolymerization of MAH, i.e. the catalyst has a half-life of up to about 30 min at the reaction temperature (6). Thus, t-butyl perbenzoate (tBPB) is effective in the preparation of LDEE-clay composites at 130 and 150 c and HDEE-clay composites at 150 C while dicumyl peroxide is less effective in LDFE-clay composites at 130 C than at 150 C. 

The effect of the components and conditions of preparation on the properties of a 70/30 LDPE/clay composite is shown in Table I. The 10/90 mixture of LDEE Bakelite Polyethylene Resin DYNH-1 (Union Carbide Corp.) and Hydrite 10 clay (Georgia Kaolin Co.) was compounded at 150 C in the Brabender Plasticorder in the presence of MAH and/or t-butyl perbenzoate (tBPB). The EE-coated clay was then mixed with additional DYNH-1 LDPE at 130°C to yield a 70/30 PE/clay composite. A 30 70 PE/clay concentrate was prepared in a similar manner at 150 C and converted to a 70/30 EE/ clay composite at 130 C. The 10/90 PE/clay concentrate is an easily handled, clay-like product while the 30/70 concentrate is... 

Isocyanatoethyl methacrylate Dow Chemical Co. t-Butyl perbenzoate Lucidol Corp. 

Fig. 3-2 First-order dependence of the polymerization rate Rp of methyl methacrylate on the monomer concentration [M], The initiator is the t-butyl perbenzoate-diphenylthiourea redox system. After Sugimura and Minoura [1966] (by permission of Wiley-Interscience, New York).

A three-step method can be applied for analysis of mixtures of hydroperoxides and peroxides, consisting of RP-HPLC separation, photolytic conversion of the emerging analyte to H2O2, by irradiation with a 254 nm UV lamp and application of the fluorometric technique depicted in equation 34 (n = 1) to determine this analyte. t-Butyl perbenzoate has LOD 0.3 mgL-1, linearity range 0.9-80 mgL-1 and RSD 6.1%3l,8b. See a similar method in Section VI.B.l. 

Figure 7.1-4. Change of solubility with pressure. Left t-butyl perbenzoate in wo-dodecane. solid line, crystallisation curve dashed line, solubility curve a, 40°C b, 30°C c, 20°C d, 10°C e, 0°C f, -10°C right synthetic lubricant oil in ethylene a, 60°C , 80°C , 110°C...

Diethoxy-1,2-bis(trimethyl-silyloxy)ethylene, 108 Zirconium(IV) acetylacetonate, 351 Acyloxylation (see also Acetoxylation) t-Butyl perbenzoate, 58 Acyloxyselenylation (see Addition reactions to carbon-carbon multiple bonds)... 

An oxidative route to 1,3-thiazoles (39) and oxazoles, which bear the requisite functionality, such as amino groups and stereocenters, for incorporation into a variety of natural products was reported. Treatment of 1,3-thiazolines (36) with CuBr (l.leq), Cu(OAc)2 (l.leq) and t-butyl perbenzoate (1.5eq) under benzene reflux gave 1,3-thiazoles (39) in about 80% yield. A plausible mechanism included generation of a Cu (III) species (37) via oxidative addition, reductive elimination to the acyloxy thiazoline (38), and syn elimination on warming to produce the thiazole (39). [94TL6803]... 

C, i.e. in conditions at which initiators are not consvimed too fast. As initiators benzoyl peroxide (BzjOj) and t-Butyl Perbenzoate (TBPB) were chosen, they are most widely used in practice. Initial concentrations were chosen so that MW of obtained polymers were within the range of 10 - 10, ... 

Catalysts are currently not covered specifically by EU directives on food contact plastics. They tend to decompose during the polymerisation process. Again, the degradation products are often predictable and may sometimes be found in the finished food contact material. However, catalysts are usually present at low levels and the degradation products are often volatile. For example, the common catalyst t-butyl perbenzoate may decompose to give benzene when used in some thermoset polymers.Tert-butyl peroxide is used as a catalyst in certain polymers and will decompose to give tert-butanol. 

SYNS tetc.BUTYLESTER KYSELINY PEROXY-BENZOOVE (CZECH) terc.BUTYLPER-BENZOAN (CZECH) t-BUTYL PERBENZOATE t-BUTYL PEROXY BENZOATE OESPEROX 10 NOVOX PERBENZOATE de BUTYLE TERTIAIRE (FRENCH) TRIGONOX C... 

While the rate of decomposition of t-butyl perbenzoate is relatively insensitive to solvent changes, t-butyl o-phenylthioperbenzoate is extremely sensitive to these changes. Rate data for the latter perester, obtained by measurement of the disappearance of the perester and by radical scavenging, are given in Table 107. In... 

NPGDA), trimethylol propane triacrylate (TMPTA), Trigonal 14 (Noury Chem. Corp. mixture of benzoin butyl ethers), benzoyl peroxide, and t-butyl perbenzoate were used as obtained from commercial suppliers without further purification. 

Reaction with unsaturated compounds (reviews Kharasch,Sosnovsky,andYang reported that, in the presence of a catalytic amount of a copper or cobalt salt, t-butyl perbenzoate reacts with an olefin to give an allylic benzoate with no allylic rearrangement with a terminal olefin the only product isolated was the allylic ester with a terminal double bond. A further example is the reaction with 1-methylene-4-f-butylcyclohexane. However, in contrast to these early reports, Kochi found by o... 

Cumene- or t-butyl hydroperoxide or t-butyl perbenzoate in conjunction with ascorbic acid or ascorbic palmitate also initiate rapid polymerization, yielding colorless composites with good mechanical properties (55). For commercial application, means must be developed for prevention of oxidation of ascorbic acid or its derivatives on prolonged storage. 

Thiazolines and 3-thiazolines are easily aromatized to the corresponding thiazoles by the action of oxidants such as nickel peroxide <94TL1379>, 2,3-dichloro-5,6-dicyano-l,4-dibenzoquinone, or t-butyl perbenzoate via the Kharasch-Sosnovsky reaction <94TL248l, 94TL6803). The aromatization of... 

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