Tert-Butyl cumyl peroxide

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. 

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]. 

Tert.butyl-cumyl-peroxide (BCUP) Trigonox T Liquid 138 180 1.17X10 = 147.0... 

Crosslinking Aryl-AlkyIperoxides Tert.-Butyl cumyl peroxide Liquid, techn. pure... 

Tert-butyl cumyl peroxide 1,1-Dimethyl benzene methanol Acetophenone Tertiary butanol... 

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. 

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

Table 15 shows that peroxyester stabiUty decreases for the alkyl groups in the following order tert — butyl > tert — amyl > tert — octyl > tert — cumyl > 3 — hydroxy — 1,1 dimethylbutyl. The order of activity of the R group in peroxyesters is also observed in other alkyl peroxides. Peroxyesters derived from benzoic acids and non-abranched carboxyUc acids are more stable than those derived from mono-a-branched acids which are more stable than those derived from di-a-branched acids (19,21,168). The size of the a-branch also is important, since steric acceleration of homolysis occurs with increasing branch size (236). Suitably substituted peroxyesters show rate enhancements because of anchimeric assistance (168,213,237). 

For the formal deoxygenation (decomposition) reaction 5, there is an enthalpy of formation value for every alcohol that matches a hydroperoxide . Using our exemplary groups, R = 1-hexyl, cyclohexyl and ferf-butyl, the liquid enthalpies of reaction are —77.9, —75.0 and —65.6 kJmoR, respectively (there is no liquid phase enthalpy of formation reported for f-butyl peroxide from Reference 4). The secondary hydroperoxides enthalpies of reaction average —77 7 kJmoR. For the three instances where there are also gas phase enthalpies of formation, the enthalpies of reaction are almost identical in the gas and liquid phases. The 1-heptyl (—60.3 kJmoR ) and 1-methylcyclohexyl (—50.6 kJmoR ) enthalpies of reaction are again disparate from the 1-hexyl and tert-butyl. If the enthalpy of reaction 5 for 1-hexyl hydroperoxide is used to calculate an enthalpy of formation of 1-heptyl hydroperoxide, it is —325 kJmoR, almost identical to values derived for it above. The enthalpies of reaction for the liquid and gaseous phases for the tertiary 2-hydroperoxy-2-methylhex-5-en-3-yne are —78.2 and —80.9 kJmoR, respectively. For gaseous cumyl hydroperoxide, the enthalpy of reaction is —84.5 kJmoR. ... 

Peroxide explosions are usually caused by heat, shock, impact, or catalysts, but the possibility of spontaneous explosions must not be left out of account, even with peroxides that are normally considered to be harmless. Among the most important protective measures in work with these substances is to wear protective glasses many organic peroxides (tert-butyl hydroperoxide, cumyl hydroperoxide, cyclohexanone peroxide, 2-butanone peroxide, diacetyl peroxide) cause serious injury on entry into the eye.315 If such an accident happens, the eye should be bathed at once with water or, better, 2% sodium hydrogen carbonate solution oily media must not be used. 

Di-tert-alkyl and di-tm-aryl peroxides (e.g. di-tert-butyl peroxide and di-cumyl peroxide) find some use in the production of heat-stable vulcanizates of natural rubber. However, the particular significance of these reagents is that their mode of reaction is rather straightforward and it has been possible to establish a direct quantitative relationship between the number of cross-links in a vulcanizate and its elastic modulus. This correlation is important to the theory of rubber-like elasticity. 

The following commercially available dialkyl peroxides are produced according to equations 24—27 di-Z fZ-butyl peroxide from hydrogen peroxide and sulfated tert-huty alcohol or isobutylene dicumyl peroxide from a-cumyl hydroperoxide and cumyl alcohol, cumyl chloride, and/or a-methylstyrene m- and -di(2-/ f2 -butylperoxyisopropyl)ben2ene [2781-00-2] from tert-huty hydroperoxide [75-91-2] and m- and -di(2-hydroxyisopropyl)ben2ene ... 

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