Benzoyl peroxide initiator

In 1988, Terry and coworkers attempted to homopolymerize ethylene, 1-octene, and 1-decene in supercritical C02 [87], The purpose of their work was to increase the viscosity of supercritical C02 for enhanced oil recovery applications. They utilized the free radical initiators benzoyl peroxide and fert-butyl-peroctoate and conducted polymerization for 24-48 h at 100-130 bar and 71 °C. In these experiments, the resulting polymers were not well studied, but solubility studies on the products confirmed that they were relatively insoluble in the continuous phase and thus were not effective as viscosity enhancing agents. In addition, a-olefins are known not to yield high polymer using free radical methods due to extensive chain transfer to monomer. 

Initiation of a chain reaction involves the formation of free radicals from an initiator. Benzoyl peroxide is a commonly used initiator. 

All four polymerization processes can be used to make PS. The reaction is an addition polymerization using a free radical initiator (benzoyl peroxide or di-tertiary butyl peroxide). Mostly, the suspension or bulk processes are... 

The phenomenon of induced decomposition, in which radicals derived from reaction of the solvent with the initiator benzoyl peroxide consume some of the initiator in a chain process, was first elucidated by Bartlett and Nozaki (equation 51), and by Cass. ... 

Cyclic azido-A3-iodane prepared by ligand exchange of A3-iodane 85 with trimethylsilyl azide is a useful reagent for direct azidation of anilines and alkanes [Eq. (82)]. Alkane azidation occurs in the presence of a radical initiator benzoyl peroxide at 80 -132 °C [152,153]. Cyano-A3-iodane serves as an efficient cyano transfer agent toward N,N-dialkylanilines [154]. 

The reaction is called an addition reaction because two monomers are added to each other with the elimination of a double bond. This is also called a chain growth polymerization reaction. However, the reaction as such does not go without the help of an unstable molecule, called an initiator, that starts the reaction. Benzoyl peroxide or i-butyl benzoyl peroxide are such initiators. Benzoyl peroxide splits into two halves under the influence of heat or ultraviolet light and thus produces two free radicals. A free radical is a molecular fragment that has one unpaired electron. Thus, when the central bond was broken in the benzoyl peroxide, each of the shared pair of electrons went with one half of the molecule, each containing an unpaired electron. 

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, ... 

Figure 10.4. Rate of methyl methacrylate chain polymerization. Left rate first order in monomer (redox initiator) [36] right rate approximately half order in initiator (benzoyl peroxide) [37].

Fig. 18. Rate R %/rainl versus conveision dependence during polymerizatMn of (i) methyl acrylate <2) ethyl acrylate and (3) butyl acrylate in the presence of SDDS (A) and AAOES (B). The graphs are plotted from the kinetic curves in F g, 9- Initiator benzoyl peroxide.

To do this, the conversion takes place in the presence of a solvent (toluene), with a free radical initiator (benzoyl peroxide) Gaseous hydrogen bromide is introduced" into the solution. The reaction is fast and highly exothermic. The reactor is cooled by the... 

Chain polymerization involves three processes chain initiation, chain propagation, and chain termination. (A fourth process, chain transfer, may also be involved, but it may be regarded as a combination of chain termination and chain initiation.) Chain initiation occurs by an attack on the monomer molecule by a free radical, a cation, or an anion accordingly, the chain polymerization processes are called free-radical polymerization, cationic polymerization, or anionic polymerization. A free radical is a reactive substance having an unpaired electron and is usually formed by the decomposition of a relatively unstable material called an initiator. Benzoyl peroxide is a common free-radical initiator and can produce free radicals by thermal decomposition as... 

This copolymer has an overall composition of 94.8% ethyl acrylate/5.2% acrylic acid with the monomer charged at a level of 39 wt% in a solution of ethyl acetate. Initially, the solvent and initiator, benzoyl peroxide in this case, are added to the reactor and heated to reflux (80°C). Forty percent of the monomer mixture is added to the reactor in one charge. Then, four equal aliquots of monomer are added 24, 50, 79, and 110 min after the initial charge. Reflux is maintained within the reactor overnight to ensure complete reaction the product is then cooled and packaged the next morning (96). 

Supercritical CO2 was used to encapsulate the polystyrene within CNTs via a two-step process. The monomer styrene together with an initiator (benzoyl peroxide) was filled into the NTs using SCCO2 (35°C, 12.0 MPa). After the impregnation period, the pressure was released over different times (8 and 1800 s) and the polymerization took place into an oven at 100°C for 24 h. 

Considering epoxy resin filled with potassium titanate whisker as an example, the specific operation is as follows. Mix bisphe-nol A-glycidyl methacrylate (bis-GMA) and triethylene-glycol dimethacrylate at a mass ratio of 1 1 as a resin matrix add initiator benzoyl peroxide (BPO) and the polymerization inhibitor butylated hydroxytoluene (BHT, 264) and blend uniformly. Then mix surface-modified potassium titanate whisker into the resin, fill into the mold, and cure in an oven at 120°C for 30 minutes. 

Tetrahydrothiophene 74, on the other hand, reacted with MA only with AIBN as an initiator. Benzoyl peroxide failed to yield any product. Jacobs and Ecke described the product as a 1 1 adduct so the structure is probably similar to the THF adduct 70. 

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