Methyl methacrylate initiation

As an example, consider the polymerization of methyl methacrylate, initiated by a,a -azobisisobutyronitrile.4 The dependence of the initial rate on the concentration of the initiator is displayed in Fig. 1-1, which shows them on a double logarithmic scale. The points define a straight line with a least-squares slope of0.496. Clearly the reaction is half-order with respect to the concentration of the initiator. 

Biesenberg, J. S. etal., J. Polym. Eng. Sci., 1976,16, 101-116 Polymerisation of methyl methacrylate initiated by oxygen or peroxides proceeds with a steady increase in velocity during a variable induction period, at the end of which a violent 90°C exotherm occurs. This was attributed to an increase in chain branching, and not to a decrease in heat transfer arising from the increasing viscosity [ 1 ]. The parameters were determined in a batch reactor for thermal runaway polymerisation of methyl methacrylate, initiated by azoisobutyronitrile, dibenzoyl peroxide or di-ferf-butyl peroxide [2],... 

The initial rate of polymerization of methyl methacrylate initiated by chromium allyls (12) in toluene showed identical dependences on monomer and catalyst concentrations, as Zr(benzyl)4 initiated polymerization of styrene. Some data for the monomer dependence are shown in Fig. 14. 

The mechanism proposed for the polymerization of styrene initiated by Zr (benzyl) 4 differs from that proposed for the polymerization of methyl methacrylate initiated by chromium allyls (12, 44)- In these papers it was considered that the concentration of complex (I) was comparable to the catalyst concentration, a fact which now seems unlikely in view of the... 

Borsig E, Lazar M, Capla M (1967) Polymerization of methyl methacrylate initiated by 3,3,4,4-tetraphenyl hexane and 1,1,2,2-tetraphenyl cyclopentane. Makromol Chem 105 212... 

Kwak Y, Matyjaszewski K (2008) Effect of initiator and ligand structures on ATRP of styrene and methyl methacrylate initiated by alkyl dithiocarbamate. Macromolecules 41 6627-6635... 

Tsubokawa et al. (12-14) have introduced radical sources of azo or peroxy groups by another methods, and successively conducted the radical polymerization of vinyl compounds, such as styrene or methyl methacrylate, to give polymer-grafted particles see Reaction (3). The grafting by the radical polymerization of methyl methacrylate, initiated from a peroxy group introduced on silica, takes place at relatively high efficiency, compared with those from azo group-introduced particles. 

Radical Polymerization of Methyl Methacrylate Initiated with... 

When the test tube is ready for use, place the methyl methacrylate-initiator solution in the test tube. Cover the neoprene stopper with the polyethylene film and stopper the test tube. 

Studies on the Anionic Polymerization of Methyl Methacrylate Initiated with Butyllithium in Toluene by Using Perdeuterated Monomer... 

However, no independent evidence is presented for the existence of this complex. In our view a simpler explanation for the lack of reaction in unbuffered solution is that the nondissociated form of ascorbic acid is a chain terminator. At the typical concentrations employed, 1-10 mM, more than 90% of ascorbic acid (pK = 4.1) is not dissociated when dissolved in pure water. At pH 6.0 only 1% is present as the protonated form. Furthermore, in their study of the photopolymerization of methyl methacrylate initiated by acriflavine-ascorbic acid, Lenka and Mohanty [180] report the rate of polymerization reaches a maximum when the ascorbic acid concentration is approximately 10 mM. The decrease in polymerization rate at higher concentrations suggests ascorbic acid participates in chain transfer and/or termination reactions. 

Straforelli (2) investigated the effect of lignin on the graft copolymerization of methyl methacrylate initiated by azo-... 

Dispersed phase methyl methacrylate initiator (AIBN)... 

Polymerization of methyl methacrylate initiated by CAN in the presence of polyglycine, polyhydroxyproline, and polyserine was also studied. Somewhat lower yield of polymer was formed in the presence of polyglycine. However, the poor reproducibility of the results did not allow a statistically supported conclusion. 

Gosh and Gosh [105] studied photoinitiated polymerization of methyl methacrylate initiated by the BP-TV,A-dimethylaniline couple, and Clarke and Shanks [106] tested the influence of a variety of amines on benzophenone-initiated polymerization. That amino radicals resulted during the initiation the polymerization by benzophenone-tertiary aromatic amines was shown by Li through the use of ESR and spin-trapping methods [107]. It was shown that the rate of photoinitiated polymerization depends on the structure of the amine. More recently [108] benzophenone-tertiary aromatic amines were studied as initiators of the free-radical polymerization of polyol acrylates. Illustrative kinetic curves recorded during photoinitiated polymerization of TMPTA are shown in Figure 23. 

Acres and Dalton (1963a) also studied the emulsion polymerization of methyl methacrylate initiated by Co y radiation using a recording dilatometer. Only the conversion-time curves were measured with constant dose rate, varying monomer concentration, and with constant monomer concentration at different dose rates. Except at the lowest monomer concentration a clear gel effect was observed, with linear rates up to that point. The linenr rates increased with increasing monomer concentration up to about 0.4 mol/liter and then leveled oif. The dependence of the rate, before the gel effect, on the dose rate was 0.4 and, unlike their findings with styrene, not dependent on the monomer concentration. Their results were consistent with those of Hummel ei al. that methyl methacrylate follows, with y radiation, the generally accepted Smith-Ewart Case 2 kinetics except for the marked gd effect. 

The polymerization of methyl methacrylate initiated by the products of the thermal degradation of 9-anthryldiazomethane can serve as an example of the synthesis of a polymer vrith terminal LM using an initiator-containing luminescent group ... 

At this same time there are data that arylsulfanamides may inhibit radical-chain process of destruction. Kinetics of inhibited radical polymerization of methyl methacrylate, initiated by dinitrile of azo - bis - isobutyric acid, was studied to evaluate inhibiting activity of carbazolsulphonamides. 

The hindrance of desorption does not affect the mobility of radical-anions on the metal surface. Hence, their dimerization with formation of still adsorbed dimeric dianions is very likely, and these may grow and form living oligomers. Degree of polymerization of the attached oligomers depends on their lifetime on the surface, and the lifetime is shortened by a cationsolvating solvent that facilitates removal of the cation from the metal lattice and therefore the desorption. This is demonstrated by Overberger (13), who studied the co-polymerization of styrene and methyl methacrylate initiated by a fine suspension of particles of metallic lithium. 

Bolland and Melville—Free radicals trapped in poly(methyl methacrylate) initiate chloroprene polimierization to give graft polymers. 

Formation of polymers with relatively narrow molecular weight distribution provides a fair evidence for the cleaness of the system. This was achieved in polymerization of meticulously purified methyl methacrylate initiated by biphenylide salts of alkali metals and carried out in polar solvents, THF or DME, at a low temperature, - 78°C360). Under... 

Polymerization of methyl methacrylate initiated by Grignard compound is most complex378, 387) and it is premature to discuss this topic in view of a paucity of information. Similarly, complex phenomena, requiring more investigation, obscure the mechanism of its polymerization in nonpolar solvents or in mixtures of polar and non-polar media. 

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