Peroxides diisopropyl peroxydicarbonate

Table 7. Radical telomerisation of TFE (DBP, DIPC,BEPH,DTBPandF113 represent dibenzoyl peroxide, diisopropyl peroxydicarbonate, butyl ethyl peroxyhexanoate, ditertiarybutyl peroxide and C1CF2CFC12, respectively) ...

Polymerization catalysts Dibenzoyl peroxide. Diisopropyl peroxydicarbonate. Trityl-sodium. 

Diisopropyl peroxydicarbonate, 3034 1 -Hydropcroxy-1 -hydroxydicyclohexyl peroxide, 3555 2-Pheny 1-2-propyl hydroperoxide, 1387... 

Bis(fluoroformyl) peroxide, 0625 Bis-3-(2-furyl)acryloyl peroxide, 3640 Bis(trichloroacetyl) peroxide, 1361 Bis(trifluoroacetyl) peroxide, 1367 Diacetyl peroxide, 1537 Dibenzenesulfonyl peroxide, 3499 Dibenzoyl peroxide, 3639 Di-3-camphoroyl peroxide, 3807 Dicrotonoyl peroxide, 2986 Dicyclohexylcarbonyl peroxide, 3667 Didodecanoyl peroxide, 3857 Di-2-furoyl peroxide, 3245 Dihexanoyl peroxide, 3554 Diisobutyryl peroxide, 3032 Diisopropyl peroxydicarbonate, 3034 Dimethanesulfonyl peroxide, 0931 Di-2-methylbutyryl peroxide, 3354 Di-l-naphthoyl peroxide, 3831 3,6-Dioxo-l,2-dioxane, 1445 Dipropionyl peroxide, 2442 Dipropyl peroxydicarbonate, 3035 Di-4-toluenesulfonyl peroxide, 3656 Peroxodisulfuryl difluoride, 4328 Phthaloyl peroxide, 2900 Potassium benzenesulfonylperoxosulfate, 2257 Potassium O-O-benzoylmonoperoxosulfate, 2684 (9-TriIIuoroacctyl-.S -lluorofonny 1 thioperoxide, 1050 See PEROXIDES, PEROXYCARBONATE ESTERS... 

Acetyl cyclohexanesulfonyl peroxide, 3028 2,2 -Biphenyldicarbonyl peroxide, 3624 Bis(2,4-dichlorobenzoyl) peroxide, 3617 Bis(2-azidobenzoyl) peroxide, 3621 Bis(3,4-dichlorobenzenesulfonyl) peroxide, 3439 Bis-3-(2-furyl)acryloyl peroxide, 3633 Bis(3-carboxypropionyl) peroxide, 2985 Bis(4-chlorobenzenesulfonyl) peroxide, 3452 Bis(bromobenzenesulfonyl) peroxide, 3447 Bis(fluoroformyl) peroxide, 0621 Bis(trichloroacetyl) peroxide, 1357 Bis(trifluoroacetyl) peroxide, 1363 Di-1-naphthoyl peroxide, 3825 Di-2-furoyl peroxide, 3239 Di-2-methylbutyryl peroxide, 3348 Di-3-camphoroyl peroxide, 3801 Di-4-toluenesulfonyl peroxide, 3649 Diacetyl peroxide, 1532 Dibenzenesulfonyl peroxide, 3493 Dibenzoyl peroxide, 3632 Dicrotonoyl peroxide, 2981 Dicyclohexylcarbonyl peroxide, 3660 Didodecanoyl peroxide, 3851 Dihexanoyl peroxide, 3548 Diisobutyryl peroxide, 3027 Diisopropyl peroxydicarbonate, 3029 Dimethanesulfonyl peroxide, 0927 3,6-Dioxo-l,2-dioxane, 1441... 

Heating benzene homologues with diisopropyl peroxydicarbonate and cupric chloride or with dibenzoyl peroxide and iodine gives isopropyloxy-carbonyl or benzoyl esters of the corresponding phenols [232,1119, 1120], Unfortunately, all three isomers are usually obtained so that the synthetic uses are limited (equation 149). 

Diisopropyl peroxydicarbonate Diacetyl peroxide Azobisisobutyronitrile Dibenzoyl peroxide Potassium persulfate f rf-Butyl hydroperoxide... 

Diisopropyl Peroxydicarbonate Dilauroyl Peroxide Dimethyldichlorosilane Dimethylhydrazine, 1,1-Dimethylamine, Anhydrous 2,4-Dinitroaniline Ethyl Methyl Ketone Peroxide... 

The usual initiators such as 2,2 -azobisisobutyronitrile, benzoyl peroxide, and lauroyl peroxide have to be decomposed to generate the free radicals which bring about the polymerization process. While there are methods which involve the use of radiation to accomplish this, these are rarely advocated it is more common to use thermal means to generate the initiating species. In order that the product be formed in a reasonable time interval, it is usual to attempt the use of these initiators at temperatures in the range of 60° to 80°C (with the notable exception of diisopropyl peroxydicarbonate which may be used in the range of 25°C to 50°C). Such temperatures are above the critical temperature of vinyl fluoride (54.7°C). Consequently, regardless of applied pressure, the monomer cannot be liquified above 54.7°C, the temperatures at which the initiators are... 

Perimidines, 2-ainino- 26,434 Periodate 26,101 Periodic add 26,265 Perkadox s. Diisopropyl peroxydicarbonate Permanganate 26,94 Peroxides... 

Diisopropyl peroxydicarbonate, Perkadox, is an effective initiator of radical additions at 30-70°, where low-boiling addenda such as acetyl chloride or acetonitrile can be used. The more stable initiators such as benzoyl or ferf-butyl peroxide do not react in these cases. E. s. J. G. Allen, J. I. G. Gadogan, and D. H. Hey, Soc. 1965, 1918. 

Suspension Polymerization, in this technique, liquid VF is suspended in water with the help of a dispersion stabilizer (70). Polymerization is initiated by an organic peroxide such as diisopropyl peroxydicarbonate below the critical temperature of VF (71,72). The reaction can also be initiated by uv light and ionizing radiation (64,73). VF dispersions are usually stabilized by water-soluble polymers such as cellulose derivatives, eg cellulose ester and sodium carboxymethylcellu-lose, and poly(vinyl alcohol). Inorganic salts such as magnesium carbonate, barium sulfate, and alkylsulfoacids are also used. 

Other initiators that have been used in polymerizing vinyl chloride are diisopropyl peroxydicarbonate, di-5ec-butyl peroxydicarbonate, terUhwiyX peroxypivalate, as well as lauroyl peroxide and benzoyl peroxide. All of these initiators, after allowances are made for variations in their half-lives at a given temperature, behave similarly as far as the two-phase polymerization of vinyl chloride is concerned [79]. There is considerable advantage, from the economic standpoint, in using an initiator such as diisopropyl peroxydicarbonate, which is active at a relatively low temperature. 

The most commonly used initiators in this system are AIBN, benzoyl peroxide, lauroyl peroxide (LPO), and diisopropyl peroxydicarbonate (IPP). The last two are probably of most interest industrially. In aromatic solvents, LPO has a half-life of 10 hr at 62°C while that of IPP is 10 hr at only 35[92]. Therefore one may expect that at the same temperature, polymerizations initiated with IPP proceed significantly more rapidly than LPO-initiated ones this, indeed, has been found. 

Table XII gives the half-lives of several initiators which are of interest in suspension polymerizations of vinyl chloride. While these data are a rough guide to the temperature-time relationship to be expected, many other factors need to be considered. For example, lauroyl peroxide brings about a polymerization process of vinyl chloride in which the maximum rate takes place between 60% and 80 o conversion whereas the rate of polymerization with diisopropyl peroxydicarbonate is much more uniform throughout the process. Also, particle structure varies with the initiator used [139]. The development of initiators has been in the direction of molecules with unsymmetrical substitution about the peroxide bridge. Data on these compounds are also included in Table XII [139, 140].

The choice of the proper peroxy initiator largely depends on its decomposition rate at the reaction temperature of the polymerization. BPO is the major initiator for bulk polymerization of polystyrene or acrylic ester polymers, where temperatures from 90°C to 220°C are encountered. Dilau-royl, dicaprylyl, diacecyl, and di- err-butyl peroxides are also used. In the case of suspension polymerization of styrene, where temperatures between 85°C and 120 C are applied, the initiators also range in activity from BPO to di-tm-butyl peroxide. In suspension polymerization of vinyl chloride (reaction temperatures of 45-60°C for the homopolymer), thermally very labile peroxides such as diisopropyl peroxydicarbonate and rm-butyl peroxy-pavilate are used. 

Laboratory studies have generally focused on the diisopropyl, dicyclohexyl and di-t-butyl derivatives. These and the. s-butyl and 2-cthylhcxyl derivatives arc commercially available.189 The rates of decomposition of the peroxydicarbonates show significant dependence on the reaction medium and their concentration. This dependence is, however, less marked than for the diacyl peroxides (36) (see 3.3.1.1.4). Induced decomposition may involve a mechanism analogous to that described for diacyl peroxides. However, a more important mechanism for primary and secondary peroxydicarbonates involves abstraction of an cx-hydrogen (Scheme 3.31).190... 

Peroyl A. See Acetyl peroxide Peroyl IPP, Peroyl IPP-27S, Peroyl IPP-50. See Diisopropyl perdicarbonate Peroyl L, Peroyl LO. See Lauroyl peroxide Peroyl MSP. See Dimyristyl peroxydicarbonate Peroyl NPP. See Di-n-propyl peroxydicarbonate Peroyl OPP. See Di (2-ethylhexyl) peroxydicarbonate... 

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