Tert-Butyl peroxypivalate

Tert-Butyl Peroxypivalate Diethyl Carbamyl Chloride... 

Solvent polarity also affects the rate of peroxide decomposition. Most peroxides decompose faster in more polar or polarizable solvents. This is true even if the peroxide is not generally susceptible to higher order decomposition reactions. This phenomenon is illustrated by various half-life data for tert-butyl peroxypivalate [927-07-1]. The 10-h half-life temperature for tert-butyl peroxypivalate varies from 62°C in decane (nonpolar) to 55°C in benzene (polarizable) and 53°C in methanol (polar). 

Copolymerization of Butadiene and Acrylonitrile. The same procedure was used except that the zinc chloride was stirred in a mixture of 30 ml. heptane and 15 ml. dioxane. Butadiene, acrylonitrile, and tert-butyl peroxypivalate were dissolved in 20 ml. heptane. The yield of polymer was 18.1 grams (84.5% ). 

Residual monomers in the latex are avoided either by effectively reacting the monomers to polymer or by physical or chemical removal. The use of tert-butyl peroxypivalate as a second initiator toward the end of the polymerization or the use of mixed initiator systems of K2S2Og and tert-butyl peroxybenzoate (56) effectively increases final conversion and decreases residual monomer levels. Spray devolatilization of hot latex under reduced pressure has been claimed to be effective (56). Residual acrylonitrile also can be reduced by postreaction with a number of agents such as monoamines (57) and dialkylamines (58), ammonium—alkali metal sulfites (59), unsaturated fatty acids or their glycerides (60,61), their aldehydes, esters of olefinic alcohols, cyanuric acid (62,63), andmyrcene (64). 

Figure 6.7-15 Infrared absorbance spectra, recorded during the thermal decomposition of tert-butyl peroxypivalate in //-heptane at 80 °C and 2000 bar r reaction time. The initial perester concentration is 0.01 mol L". ...

In the above equations, flow rates of solvent (n-butane), initiator Ii (tert-butyl peroxypivalate) and initiator h (rm-butyl 3,5,5 trimethyl-peroxyhexaonate) are represented by Fs, Fi,i and Fi,2 respectively. 

Beilstein Handbook Reference) Aztec f-Butyl Peroxypivalate-75 OMS BRN 1704745 EINECS 213-147-2 Esperox 31M Lupersol 11 Peroxypivalic acid, tert-butyl ester Propane- peroxoic xid, 2,2-dimethyl-, 1,1-dimethylethyl ester t-Butyl peroxypivalate tert-Butyl peroxypivalate tert-Butyl trimethylperoxyxetate Trigonox 25/75 Trigonox 25-C75. An initiator for LDPE polymerization, styrenics, and PVC. Supplied x a solution in odorless mineral spirits. Liquid mp = -17" insoluble in H2O. Akzo Chemie Catalyst Resources Inc. 

Graft/Blend Polymers. These polymers were prepared by dissolving PVC in either methyl ethyl ketone or tetrahydrofuran, followed by the appropriate 2-ethylhexyl acrylate/acrylonitrile monomer charge and the free radial initiator, e.g., Lupersol 11 (tert-butyl peroxypivalate). This solution was then heated to 50°-70°C in 4-oz bottles, 2-1. glass reactors, or larger glass-lined autoclaves. Polymerization times were normally 12-16 hrs a conversion check was then made, and, if conversion was complete, films were cast from the polymer solution. 

Allyl chloroformate-a-Olefin tert-Butyl peroxypivalate X u... 

In another patent [53], a seeded emulsion polymerization is described. The seed polymer is prepared by emulsion polymerization of vinyl fluoride using tert-butyl peroxypivalate as initiator and ammonium G>-hydroperfluoronona-noate as emulsifier. The process required 9 hr at 40 kg/cm (0.4 MPa). The resultant particles were described as having an average diameter of 18/an (which we would consider a a bit large for emulsion particles) and are said to be present in a concentration of 2.26 X lo particles/dm. In the second stage of the process, this seed latex (400 ml in a total volume of 1.8 dm ) was subjected to the same reaction conditions a second time. 

An excellent review on vibrational spectroscopy in supercritical fluids was published in 1995 by Poliakoff et al. [6]. In the late 1990s, Kessler et al. [7] developed IR and Raman spectroscopy for the investigation of rapid high-pressure reactions in optical cells. Raman was preferred to IR for the determination of the decomposition rate of peroxides under high pressure. They studied the decomposition of tert-butyl peroxypivalate at pressure up to 180 MPa and temperatures of 90-160 °C. A typical Raman spectrum is presented in Fig. 5.3. 

A typical polymerization consisted of equimolar amounts of styrene (S) and acrylonitrile (AN (0.02 moles). They were copolymerized with and without 10% mole ratio ZnCla (0.002 moles) in tert.-butyl alcohol (20 ml) in the presence of the initiator tert.-butyl peroxypivalate (tBPP, Lupersol-11, 0.05 g). The polymerizations were conducted at 50°C in 1 oz. amber bottles for 96 hrs. 

Residual monomers in the latex are avoided either by effectively reacting the monomers to polymer or by physical or chemical removal. The use of tert-butyl peroxypivalate as a second initiator toward the end of the polymerization or the use of mixed initiator systems of K2S2O8 and tert-butyl peroxybenzoate... 

Perfluoro-2-inethylene-l,3-dioxolane monomers copolymerizes with various commercially available fluorovinyl monomers, too. Perfluoro-3-methylene-2,4-dioxabicyclo [3,3,0] octane (Figure 16.5F) was copolymerized with chlorotrifluo-roethylene (CTFE), perfluoropropyl vinyl ether, perfluoromethyl vinyl ether, and vinylidene fluoride [23] by a free radical initiator such as perfluorodibenzoylperox-ide or tert-butyl peroxypivalate in bulk or in solution, respectively (see Figure 16.9). 

The synthesis of tert-butyl peroxypivalate from pivaloyl chloride and deprotonated tert-butyl peroxide has been investigated using segmented flow [34]. The small interfadal tension between the two phases caused problems in this process, which was solved using higher dilutions to achieve a regular droplet formation. 

A typical polymerization run was conducted in a stirred one-gallon (3.7 liters) stainless steel reactor equipped with baffles and a cooling coil, rated at 69 MPa. The vessel was charged with 2,470 ml of water, 908 g of vinylidene fluoride, 30 g of an aqueous methyl hydroxypropyl cellulose solution, and 5 g of tert-butyl peroxypivalate. Water pressure was raised to 5.5 MPa at 25°C under which the liquid monomer density is 0.69 g/ml. The reactor was heated to 55°C, increasing the pressure to 13.8 MPa. The reaction was continued for four hours during which 800 ml of water was pumped into the vessel to keep the pressure constant. 

The efficiency values of the peroxyesters under investigation listed in Table 4 are in the range of 0.4tert-Butyl peroxy-2-ethylhexanoate (TBPEH) and tert-Butyl peroxypivalate (TBPP), no literature values for/have been reported so far. Luft and co-workers measured the initiator consumption of TBPEH and TBPP in ethene polymerization at 1700 bar and found that of TBPEH to... 

---