Cumyl peroxide

AMINES - LOWERALIPHATIC AMINES] (Vol 2) tert-Butyl tert-cumyl peroxide [3457-61-2]... 

The chemistry of the di-/-butyl and cumyl peroxides is relatively uncomplicated by induced or ionic decomposition mechanisms. However, induced decomposition of di-/-butyl peroxide has been observed in primary or secondary alcohols31" "14 (Scheme 3.37) and primary or secondary amines.312 The reaction... 

Two types of networks were prepared (i) randomly crosslinked polybutadiene, and (ii) model urethane networks, (a) polybutadiene based, and (b) poly(e-caprolactone) based. The randomly crosslinked networks were prepared from polybutadiene (Duragen 1203 obtained from General Tire and Rubber Co.) crosslinked with di-cumyl peroxide. Specifications of the as obtained polybutadiene are given in Table I. Polybutadiene was purified by dissolving in benzene and precipitating in methanol. Precipitated polybutadiene was redissolved in benzene. Seven different weights of dicumyl... 

The oxidation of primary and secondary alcohols in the presence of 1-naphthylamine, 2-naphthylamine, or phenyl-1-naphthylamine is characterized by the high values of the inhibition coefficient / > 10 [1-7], Alkylperoxyl, a-ketoperoxyl radicals, and (3-hydroxyperoxyl radicals, like the peroxyl radicals derived from tertiary alcohols, appeared to be incapable of reducing the aminyl radicals formed from aromatic amines. For example, when the oxidation of tert-butanol is inhibited by 1-naphthylamine, the coefficient /is equal to 2, which coincides with the value found in the inhibited oxidation of alkanes [3], However, the addition of hydrogen peroxide to the tert-butanol getting oxidized helps to perform the cyclic chain termination mechanism (1-naphthylamine as the inhibitor, T = 393 K, cumyl peroxide as initiator, p02 = 98 kPa [8]). This is due to the participation of the formed hydroperoxyl radical in the chain termination ... 

Three peroxides with aromatic substituents have reported enthalpy of vaporization data, all from the same source". The enthalpies of vaporization of cumyl hydroperoxide and ferf-butyl cumyl peroxide are the same, which makes us skeptical of at least one of these values. The calculated b value for cumyl hydroperoxide is 31.5, consistent with the alkyl hydroperoxides. The calculated b value for tert-butyl cumyl peroxide is 15.4 and more than twice that for the mean of the dialkyl peroxides. The structurally related tert-butyl p-isopropylcumyl peroxide has a b value of 8.8 and so is consistent with the other disubstituted peroxides. 

The gas phase enthalpies of reaction 6 for the variously unsaturated peroxides are also consistent, with one exception. The values are ieri-butyl cumyl peroxide, —288.5 kJmol [l,4-phenylenebis(l-methylethylidene)]bis[(l,l-dimethylethyl) peroxide" (normalized for two peroxy groups), —287.1 kJmol 1,1-dimethylethyl-l-methyl-l-[4-(l-methylethyl)phenyl]ethyl peroxide, —276.6 kJmol and 2-tert-butylperoxy-2-methylhex-5-en-3-yne, —305.8 kJmor. The last species named also has a disparate liquid phase enthalpy of reaction, —344.9 kJ mol . The only solid phase reaction enthalpy, for [l,4-phenylenebis(l-methylethylidene)]bis[(l,l-dimethylethyl) peroxide (normalized for two peroxy groups), is —357.2 kJmol . 

Disproportionation reaction 7 might be expected to be thermoneutral in the gas phase and perhaps less so in the liquid phase where there is the possibility of hydrogen-bonding. Only for gas phase dimethyl peroxide is the prediction true, where the reaction enthalpy is —0.2 kJmoD. The liquid phase enthalpy of reaction is the incredible —61.5 kJmoD. Of course, we have expressed some doubt about the accuracy of the enthalpy of formation of methyl hydroperoxide. For teri-butyl cumyl peroxide, the prediction for thermoneutrality is in error by about 6 kJmor in the gas phase and by ca 9 kJmoD for the liquid. The enthalpy of reaction deviation from prediction increases slightly for tert-butyl peroxide — 14kJmol for the gas phase, which is virtually the same result as in the liquid phase, — 19kJmol . The reaction enthalpy is calculated to be far from neutrality for 2-fert-butylperoxy-2-methylhex-5-en-3-yne. The enthalpies of reaction are —86.1 kJmoD (g) and —91.5 kJmol (Iq). This same species showed discrepant behavior for reaction 6. Nevertheless, still assuming thermoneutrality for conversion of diethyl peroxide to ethyl hydroperoxide in reaction 7, the derived enthalpies of formation for ethyl hydroperoxide are —206 kJmoD (Iq) and —164 kJmoD (g). The liquid phase estimated value for ethyl hydroperoxide is much more reasonable than the experimentally determined value and is consistent with the other n-alkyl hydroperoxide values, either derived or accurately determined experimentally. 

Butter, peroxide value, 658, 660, 665 t-Butyl alcohol, tetroxide formation, 740 t-Butyl cumyl peroxide air pollutant, 622 determination, 707 hydroperoxide determination, 685 t-Butyl hydroperoxide (TBHP)... 

These values were compared with independent estimates of the °roor/ro ,ro values from thermochemical cycles, where data were available to evaluate them. In the case of di-cumyl peroxide, for example, the E° obtained experimentally differs from the result of a thermodynamic calculation by only 30 mV. It is of interest to note that the uncorrected a data would have led to °roor/rovro values only slightly negative to the corrected ones (0.06-0.07 V). The good agreement in these cases was used as the basis to support the use of the convolution approach to estimate °roor/rovro for systems where the necessary values for thermochemical estimates are not available. This has been particularly useful in the study of endoperoxides and was used to estimate the standard reduction potential of the antimalarial agent, artemisinin. ... 

From the decomposition mechanism and the products formed it can be deduced that DCP primarily generates cumyloxy radicals, which further decompose into highly reactive methyl radicals and acetophenone, having a typical sweet smell. Similarly, tert-butyl cumyl peroxide (TBCP) forms large quantities of acetophenone, as this compound still half-resembles DCP. From the decomposition products of l-(2-6 rt-butylperoxyisopropyl)-3-isopropenyl benzene ( ), it can be deduced that the amount of aromatic alcohol and aromatic ketone are below the detection limit (<0.01 mol/mol decomposed peroxide) furthermore no traces of other decomposition products could be identified. This implies that most likely the initially formed aromatic decomposition products reacted with the substrate by the formation of adducts. In addition, unlike DCP, there is no possibility of TBIB (because of its chemical structure) forming acetophenone. As DTBT contains the same basic tert-butyl peroxide unit as TBIB, it may be anticipated that their primary decomposition products will be similar. This also explains why the decomposition products obtained from the multifunctional peroxides do not provide an unpleasant smell, unlike DCP [37, 38]. 

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