Polymerization of methyl methacrylate and

AIBN was synthesized using C-labeled reagents and the tagged compound was used to initiate polymerization of methyl methacrylate and styrene. 

Formation of block polymers is not limited to hydrocarbon monomers only. For example, living polystyrene initiates polymerization of methyl methacrylate and a block polymer of polystyrene and of polymethyl methacrylate results.34 However, methyl methacrylate represents a class of monomers which may be named a suicide monomer. Its polymerization can be initiated by carbanions or by an electron transfer process, the propagation reaction is rapid but eventually termination takes place. Presumably, the reactive carbanion interacts with the methyl group of the ester according to the following reaction... 

A plot of the initial reaction rate versus concentration, on logarithmic scales. The reaction is the polymerization of methyl methacrylate, and the concentration is that of the initiator, azobisisobutyronitrile. The slope is 0.496, showing that the reaction is half-order with respect to the initiator concentration. 

Solomon (3, h, 5.) reported that various clays inhibited or retarded free radical reactions such as thermal and peroxide-initiated polymerization of methyl methacrylate and styrene, peroxide-initiated styrene-unsaturated polyester copolymerization, as well as sulfur vulcanization of styrene-butadiene copolymer rubber. The proposed mechanism for inhibition involved deactivation of free radicals by a one-electron transfer to octahedral aluminum sites on the clay, resulting in a conversion of the free radical, i.e. catalyst radical or chain radical, to a cation which is inactive in these radical initiated and/or propagated reactions. 

Indenylidene compounds VIII, K, XXI, XXIII, XXVIIIa and XXVIIIb act as atom transfer radical polymerization catalysts for the polymerization of methyl methacrylate and styrene in high yields and with good control (Table 8.7). The catalytic activity can be dramatically improved by transforming the complexes into cationic species by treatment with AgBp4 [61]. 

One of the early specialized techniques used for the study of radical reactions was the rotating sector method. The use of this technique (Fig. 6) for determining reaction kinetics was demonstrated by Melville for the gas phase polymerization of methyl methacrylate, and later by Bartlett and Swain for the liquid phase reaction, and by Carlsson and Ingold for tin hydride reductions. ... 

Fig, 2l, Polymerization of methyl methacrylate and chloroprene by rubber mastication (69). 1 23.8% methyl methacrylate and 24.2% chloroprene added initially. 2 24.2% chloroprene polymerized, then 23.8% methyl methacrylate. 3 23,8% methyl methacrylate polymerized,... 

Present View of the Anionic Polymerization of Methyl Methacrylate and Related Esters in Polar Solvents... 

A review is given on the kinetics of the anionic polymerization of methyl methacrylate and tert.-butyl methacrylate in tetrahydrofuran and 1,2-dimethoxy-ethane, including major results of the author s laboratory. The Arrhenius plots for the propagation reaction+are linear and independent of the counterion (i.e. Na, Cs). The results are discussed assuming the active centre to be a contact ion pair with an enolate-like anion the counterion thus exhibiting little influence on the reactivity of the carbanion. 

The polymerizations of methyl methacrylate and methyl acrylate in the presence of triethyl aluminum are photochemical. The initiator forms a complex with the monomer which absorbs light at 400 mfi. The polymerzaition shows different behaviour from normal stationary radical polymerization. Firstly, the decay of polymerization after extinction of illumination is much slower than the decay theoretically expected for normal radical polymerization. 

Terminal air oxidation of polystyrene has recently been carried out by degradation of polystyrene in the presence of azo-bis-isobutyronitiile and air oxygen the polystyrene dihydroperoxide can initiate the polymerization of methyl methacrylate and acrylonitrile [193, 194). The yield of homopolymer is very low, indicating an exceptional difference of efficiency between the macroradical and the OH radical. 

Merrett, F. M. The interaction of polymerizing systems with rubber and its homologues. Part 2. Interaction of rubber in the polymerization of methyl methacrylate and of styrene. Trans. Faraday Soc. 50, 759 (1954). 

Robertson, E. E. Diffusion control in the polymerizations of methyl methacrylate and styrene. Trans. Faraday Soc. 52, 426 (1956). 

Azad and Fitch (5) investigated the effect of low molecular weight hydrocarbon additives on the formation of colloidafr particles in suspension polymerization of methyl methacrylate and vinyl acetate. It was found that the additives n-octane, n-dodecane, n-octadecane, n-tetracosane and mineral oil exerted a thermodynamic affect depending upon water-solubility and molecular weight. Since these effects on emulsion polymerization have not been considered by the earlier investigators, we have chosen n-pentane and ethyl benzene as additives with limited water-solubility and n-octadecane, and n-tetracosane as water-insoluble ones. Seeded emulsion polymerization was chosen so that the number of particles could be kept constant throughout the experiments and only the effect of the other parameters on the rate could be determined. 

The kinetics of free-radical polymerization of methyl methacrylate and other monomers with small amounts of S02 and tert-butyl hydroperoxide in bulk and solution have been investigated by P. Ghosh and... 

Polymerization of Methyl Methacrylate and Other Vinyl Monomers Activated by Low Concentrations of S02... 

Table 6. Photoinduced decomposition of onium salts by PhCO—C(OR1)R2Ph quantum yields of a-cleavage (<)> ), quantum yields on onium salt decomposition (ln), quantum yields of polymerization of methyl methacrylate (< > ) and the ratio of polymerization rate in presence (Rp) and absence of onium salts (R°) (measured in acetonitrile/water 90 vol%, X = 365 nm, absence of oxygen, concentration of onium salt 1 x 10 2 mol 1" )...

TABLE 4. Effects of Polymerization of Methyl Methacrylate and Styrene on Their Molar Refractions, Densities, and Refractive Indices... 

The sensitizer is excited by light to the triplet state and, in the next step, the excitation energy is transferred to the monomer. From the monomer in the triplet state, the initiating radicals are formed. The polymerization of methyl methacrylate and acrylamide in the presence of uranyl ions is a classic example [68, 69],... 

As a rule, the aggregation of lithium ester enolates is mainly governed by concentration, temperature and structure of the ester group. There is thus no reason for the polymerization of methyl methacrylate and f-butyl methacrylate to be influenced by the same experimental parameters. 

The validity of assumption (ii) above is less certain. Braun et al (26) have reported that semi-pinacol radicals can initiate the polymerization of methyl methacrylate and styrene at temperatures above 40° C. The semi-pinacol radicals were generat l by thermolysis of aromatic pinacols, and kinetic studies indicated that the initiation malianism involved transfer of a hydrogen atom from the semi-pinacol radical to monomer, Le. 

Benzil has frequently been used as a means of generating free radicals in polymerization systems subjected to ultra-violet irradiation 11, 16, 56—58). In studies of the benzil-photoinitiated polymerizations of methyl methacrylate, and vinyl acetate, Melville (16) assumed that initiation was brought about by fragmentation of photoexcited benzil into two benzoyl radicals. However a survey of the photochemistry of benzil 34) indicates that such a cleavage does not in fact take place in solution studies of the products formed on irradiation of benzil in cyclohexane (59), cumene and isopropanol (60) can be rationalised on the basis of initial hydrogen abstraction from solvent by photoexcit i benzil, e.g. 

Cp2TiCl2 has been assessed as additive that controls polymer chain growth in the polymerization of methyl methacrylate.1224 Methyl methacrylate is easily polymerized in the photopolymerization with Cp2TiCl2 in a water-methanol mixture under irradiation of a 15 W fluorescent room lamp. The polymerization proceeded heterogeneously.1225 This process in the presence of 2,2 -bipyridyl, 1,10-phenanthroline, or sparteine as the chelating reagent has been studied.1226 Similar studies on the polymerization of methacrylate monomers such as methyl methacrylate, ethyl methacrylate, phenyl methacrylate, and benzyl methacrylate at 40 °C have also been performed.1227 The results of co-polymerization of methyl methacrylate and acrylonitrile indicate that this process proceeds through a radical mechanism.1228 The mechanism of the controlled radical polymerization of styrene and methyl methacrylate in the... 

Elias et al.82-84) and Yamada et al.87,88 have independently reported that an isokinetic relationship exists between (AHf - AH ) and (AS - ASg) in the free radical polymerization of methyl methacrylate and methacrylic acid in different solvents ... 

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