Methyl methacrylate initiated with

Radical Polymerization of Methyl Methacrylate Initiated with... 

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

Hatada K, Kitayama T, Fumikawa K, Ohta K, Yuki H. Studies on the anionic polymerization of methyl methacrylate initiated with butyllithium in toluene by using perdeuterated monomer. In McGrath JE, editor. Anionic Polymerization. Kinetics, Mechanisms and Synthesis. ACS Symposium Series. Volume 166. Washington (DC) American Chemical Society 1981. p 327. 

Ozturk T, Yihnaz SS, Hazer B, Menceloglu YZ. ATRP of methyl methacrylate initiated with a bifunctional initiator bearing bromomethyl fimctional groups synthesis of the block and graft copolymers. J Polym Sci, Part A Polym Chem 2010 48 1364-73. 

There are some indications that the situation described above has been realized, at least partially, in the system styrene-methyl methacrylate polymerized by metallic lithium.29 29b It is known51 that in a 50-50 mixture of styrene and methyl methacrylate radical polymerization yields a product of approximately the same composition as the feed. On the other hand, a product containing only a few per cent of styrene is formed in a polymerization proceeding by an anionic mechanism. Since the polymer obtained in the 50-50 mixture of styrene and methyl methacrylate polymerized with metallic lithium had apparently an intermediate composition, it has been suggested that this is a block polymer obtained in a reaction discussed above. Further evidence favoring this mechanism is provided by the fact that under identical conditions only pure poly-methyl methacrylate is formed if the polymerization is initiated by butyl lithium and not by lithium dispersion. This proves that incorporation of styrene is due to a different initiation and not propagation. 

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. 

We have recently initiated our investigation of blends by examining the compatibility between our modified polymer sample 4 and poly(methyl methacrylate). Mixtures with a composition of between 10% and 30% of sample 4 yield compatible blends which are transparent under a polarized light microscope, and are characterized by a single Tg. Mixtures richer than 60% of 4 undergo complete phase separation. 

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],... 

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. 

Fig. 14. Polymerization of methyl methacrylate (MMA) with the enolatealuminum porphyrin (2, R=Me)-triphenylboron [( 5445)36] system (TPP)AlMe (1, X=Me) as initiator ([MMA]q/[1 (X=Me)]o=200, [1 (X=Me)]o=16.2 mM), C6H5 as solvent, rt, (C6H5)3B added ([( 5445)36]q/[2 (R=Me)]o=1.0) after irradiation for 3h (9.3% conversion). GP profiles (T44F as eluent) of the polymerization mixture at 100% conversion (4 h), monitored with differential refractometer and UV (269 nm) detectors...

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. 

Many papers have been published on the polymerization of methyl methacrylate (MMA) with alkylllthlum. It was reported that In the Initiation step an attack of alkylllthlun on monomer occurred In the first few seconds and took place on both olefinlc and carbonyl double bonds and a considerable amount of oligomer was formed in the early stage of the polymerization (1, 3 4 ... 

The previous concepts may be illustrated with the experimental determination of the evolution of reaction rate, measured by DSC at T = 60°C, for the copolymerization of methyl methacrylate (MMA) with variable amounts of ethylene glycol dimethacrylate (EGDMA), a vinyl-divinyl system (Sun et al., 1997). The reaction was initiated with 2,5-dimethyl-2,5-bis(2-ethylhexanoyl)peroxy hexane. 

The effect of non-uniform polymer composition is shown in Figure 11 for the case of a 50/50-methyl methacrylate/ethyl acrylate copolymer made by a linear power feed process in which the near tank initially contained only ethyl acrylate and the far tank only methyl methacrylate. Compared with its uniform counterpart, the non-uniform polymer had a T D approximately 25° lower and a respectable... 

J.R. Ebdon, D. Price, B.J. Hunt, P. Joseph, F. Gao, G.J. Milnes, and K.L. Cunhffe, Flame retardance in some polystyrenes and poly(methyl methacrylate)s with covalently bound phosphorus-containing groups Initial screening experiments and some laser pyrolysis mechanistic studies. Polym. Degrad. Stab., 69, 267-277 (2000). 

Structure of Polymers of Methyl Methacrylate Prepared with Free Radical Initiators... 

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. 

Usually, all the initiator used cannot be accounted for if each macromolecule or oligomer is assumed to contain only one initiator fragment. By polymerizing methyl methacrylate-d8 with nondeuterated n-butylmagnesium bromide, the fate of the initiator molecules could be studied in detail by H-NMR [22,38-44]. In toluene at —78 C, n-butylmagnesium bromide attacks equally the C=C [Eq. (2)]... 

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. 

Problem 7.16 Bulk polymerization of styrene in the presence of 1 g/L of AIBN initiator at 60°C gave a measured polymerization rate of 5.92 mol/L-s. Predict the rate of copolymerization at 60°C of a mixture of styrene (Mi) and methyl methacrylate (M2) with 0.579 mole fraction styrene and the same initial concentration of the initiator as in the homopolymerization case. Compare the rates predicted from chemical control, diffusion control, and combined models with the experimental value of 4.8x10 mol/L-s [25]. Use relevant kp and kt values for homopolymerization from Table 6.7 and assume 0 = 15. [Other data ri = 0.52, T2 = 0.46 monomer density = 0.90 g/cm .]... 

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... 

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