Polymerization methyl methacrylate, MMA

In 1962, Kimura, Takitani and Imoto (1) found that an aqueous solution of starch could easily polymerize methyl methacrylate (MMA) and about a half of polymerized MMA grafted on starch. This novel polymerization was called as "uncatalyzed polymerization". Since then, a lot of macromolecule was applied, instead of starch, and many of them were effective to initiate the radical polymerization of MMA. 

Spadaro et al. - polymerized methyl methacrylate (MMA) monomers in the presence of acrylonitrile-butadiene rubber by y-irradiation at a temperature of 70°C. For pure MMA, a total dose of 4 kGy is enough to complete polymerization and further irradiation (6.3 kGy) leads to a degradation of PMMA macromolecules. On the contrary, for PMMA/ABN blends, a higher dose... 

A new ABC star was also synthesized by modifying the above-mentioned procedure. An in-chain-SiCl-functionalized AB diblock copolymer (A PS and B PI) was first prepared by a procedure similar to that described above, followed by reacting the silyl chloride function with a dilithium agent, Li(CPh2CH2CH2CPh2)Li, to change the reaction site to 1,1-diphenylaIk-yllithium (Sioula et al, 1998). This new anionic reaction site was used to polymerize methyl methacrylate (MMA), yielding a well-defined ABC star composed of PS, PI, and PMMA (Mn = 77 000 g/mol, MJM = 1.06). 

Otsu indeed observed some features of living/controlled radical polymerization when polymerizing methyl methacrylate (MMA) with the special azo-initiator 5 (Scheme 4.4). Thus, number average degree of polymerization DPji increased linearly with monomer conversion, and the molecular weight of the polymer increased when it was heated at 80 °C in the presence of fresh monomer. 

In this study, extending the concept of localizing bubble nucleation in a confined domain, nanocellular foam was prepared with commodity polymer blends, polystyrene (PS) and poly (methyl methacrylate) (PMMA). The polymer blend was prepared by polymerizing methyl methacrylate (MMA) monomer in polystyrene matrix after dissolving the monomer into the matrix. The polymerization in polymer matrix provides highly dispersed PMMA domains. The polymer blend was then foamed by CO2. The effects of blend ratio, foaming temperature and depressurization rate on bubble diameter as well as bubble density were investigated. 

Acrylics. Acetone is converted via the intermediate acetone cyanohydrin to the monomer methyl methacrylate (MMA) [80-62-6]. The MMA is polymerized to poly(methyl methacrylate) (PMMA) to make the familiar clear acryUc sheet. PMMA is also used in mol ding and extmsion powders. Hydrolysis of acetone cyanohydrin gives methacrylic acid (MAA), a monomer which goes direcdy into acryUc latexes, carboxylated styrene—butadiene polymers, or ethylene—MAA ionomers. As part of the methacrylic stmcture, acetone is found in the following major end use products acryUc sheet mol ding resins, impact modifiers and processing aids, acryUc film, ABS and polyester resin modifiers, surface coatings, acryUc lacquers, emulsion polymers, petroleum chemicals, and various copolymers (see METHACRYLIC ACID AND DERIVATIVES METHACRYLIC POLYMERS). 

Kondo maintained his interest in this area, and with his collaborators [62] he recently made detailed investigations on the polymerization and preparation of methyl-4-vinylphenyl-sulfonium bis-(methoxycarbonyl) meth-ylide (Scheme 27) as a new kind of stable vinyl monomer containing the sulfonium ylide structure. It was prepared by heating a solution of 4-methylthiostyrene, dimethyl-diazomalonate, and /-butyl catechol in chlorobenzene at 90°C for 10 h in the presence of anhydride cupric sulfate, and Scheme 27 was polymerized by using a, a -azobisi-sobutyronitrile (AIBN) as the initiator and dimethylsulf-oxide as the solvent at 60°C. The structure of the polymer was confirmed by IR and NMR spectra and elemental analysis. In addition, this monomeric ylide was copolymerized with vinyl monomers such as methyl methacrylate (MMA) and styrene. 

When the polymer was prepared by the suspension polymerization technique, the product was crosslinked beads of unusually uniform size (see Fig. 16 for SEM picture of the beads) with hydrophobic surface characteristics. This shows that cardanyl acrylate/methacry-late can be used as comonomers-cum-cross-linking agents in vinyl polymerizations. This further gives rise to more opportunities to prepare polymer supports for synthesis particularly for experiments in solid-state peptide synthesis. Polymer supports based on activated acrylates have recently been reported to be useful in supported organic reactions, metal ion separation, etc. [198,199]. Copolymers are expected to give better performance and, hence, coplymers of CA and CM A with methyl methacrylate (MMA), styrene (St), and acrylonitrile (AN) were prepared and characterized [196,197]. 

Although carbonyl compounds, such as formaldehyde (27,28], can couple with Ce(IV) ion to initiate acrylonitrile (AN) or methyl methacrylate (MMA) polymerization, the remarkable activity of aliphatic aldehyde had not been noticed until the paper of Sun et al. [29] was published. They found that aliphatic aldehydes always... 

In this short initial communication we wish to describe a general purpose continuous-flow stirred-tank reactor (CSTR) system which incorporates a digital computer for supervisory control purposes and which has been constructed for use with radical and other polymerization processes. The performance of the system has been tested by attempting to control the MWD of the product from free-radically initiated solution polymerizations of methyl methacrylate (MMA) using oscillatory feed-forward control strategies for the reagent feeds. This reaction has been selected for study because of the ease of experimentation which it affords and because the theoretical aspects of the control of MWD in radical polymerizations has attracted much attention in the scientific literature. 

The polymerization of methyl methacrylate (MMA) by Cu(ll) amidinate complexes (Scheme 222) in combination with alkyl aluminum complexes has been reported. The preferred alkylating agent is methylalumoxane (MAO) in... 

The Emulsion Polymerization Model (EPM) described in this paper will be presented without a detailed discussion of the model equations due to space limitations. The complete set of equations has been presented in a formal publication (Richards, J. R. et al. J. AppI. Poly. Sci . in press). Model results will then be compared to experimental data for styrene and styrene-methyl methacrylate (MMA) copolymers published by various workers. 

As an even more explicit example of this effect Figure 6 shows that EPM is able to reproduce fairly well the experimentally observed dependence of the particle number on surfactant concentration for a different monomer, namely methyl methacrylate (MMA). The polymerization was carried at 80°C at a fixed concentration of ammonium persulfate initiator (0.00635 mol dm 3). Because methyl methacrylate is much more water soluble than styrene, the drop off in particle number is not as steep around the critical micelle concentration (22.) In this instance the experimental data do show a leveling off of the particle number at high and low surfactant concentrations as expected from the theory of particle formation by coagulative nucleation of precursor particles formed by homogeneous nucleation, which has been incorporated into EPM. 

Syntheses. Isotactic poly(methyl methacrylate) was synthesized by the method of Tsuruta et al. (9 ). Under a nitrogen atmosphere, a quantity of 6 mL (0.056 mole) of methyl methacrylate (MMA) dried over 4A molecular sieve was dissolved in 24 mL of similarly dried toluene. To the glass vial containing the reaction was added 0.65 mL of 1.6 M n-butyllithium, and the reaction was kept at -78°C in a dry ice/isopropanol bath. The polymerization was halted 24 hr later with the addition of hydrochloric acid and methanol (methanol/water 4.1 by volume). The polymer was dried in vacuo at 50°C, redissolved in methylene chloride, precipitated by being poured into water-containing methanol, and dried in vacuo at 50°C. Tacticlty and composition were verified with % NMR. Yield 47%. 

Cross-linked polymeric materials with optical transparency and biocompatibility are used to construct hard contact lenses. The monomers commonly used in hard contact lenses possess a high degree of hydrophobicity due to their inability to form hydrogen bonds with water. The ester methyl methacrylate (MMA) (Fig. 14.6.1), CH2C(CH3)COOCH3, was the first monomeric unit used in 1948. 

A range of rare earth metal complexes were subsequently shown to catalyze ethylene polymerization and, on occasion, living characteristics have been reported.226-228 Dimeric hydrides such as (79)—(82) are extremely active with turnover numbers > 1800 s-1 recorded for (79) at room temperature. The samarium hydride (82) also effects the block copolymerization of methyl methacrylate (MMA) and ethylene 229 further discussion may be found in Section 9.1.4.4. 

Characteristic initiation behavior of rare earth metals was also found in the polymerization of polar and nonpolar monomers. In spite of the accelarated development of living isotactic [15] and syndiotactic [16] polymerizations of methyl methacrylate (MMA), the lowest polydispersity indices obtained remain in the region of Mw/Mn = 1.08 for an Mn of only 21 200. Thus, the synthesis of high molecular weight polymers (Mn > 100 x 103) with Mw/Mn < 1.05 is still an important target in both polar and nonpolar polymer chemistry. Undoubtedly, the availability of compositionally pure materials is a must for the accurate physical and chemical characterization of polymeric materials. 

The variations in fluorescence intensity of compound 1 during the polymerization reaction of methyl methacrylate (MMA), ethyl methacrylate (EMA) and n-butyl methacrylate (n-BMA), initiated using AIBN at 70 °C, are shown in Figure B8.1.1. 

The kinetics of methyl methacrylate (MMA) polymerization in ethyl acetate/water two phase systems was described as being more well-behaved ( ). Using hexadecylpyridinium chloride (HPC) as the phase transfer catalyst, Rp was found to be approximately first order in MMA concentration. In support of a typical phase transfer mechanism, it was found that... 

The bone cement used in these studies was a two-component system. The liquid component [9.75 mL methyl methacrylate (MMA) 0.25 mL A,A-dimethyl-p-toluidine (DMPT) 75 mg/kg hydroquinone] was mixed with a solid component [3.0 g poly(methyl methacrylate) (PMMA) 15.0 g MMA-styrene copolymer benzoyl peroxide, mass fraction 2% 2.0 g BaSOJ to form the cement. Dissolution of the solid component proceeded simultaneously with polymerization once the cement was mixed. 

POLYMERIZATION OF 2-HYDROXYETHYL METHACRYLATE (HEMA) AND METHYL METHACRYLATE (MMA)... 

Ruthenium(II)-NHC systems ean be used for atom transfer radical polymerization (ATRP). Generally, similar results as for the analogous phosphine complexes are obtained. For the ATRP of styrene and methyl methacrylate (MMA) [(NHC)2peBr2] was found to rival copper(I)-based systems and to yield poly (MMA) with low polydispersities. Polymerizations based on olefin metathesis that are catalyzed by ruthenium-NHC complexes are discussed separately vide supra). 

Fig. 2 Effects of metal salts, ligands, and initiators on Cmma (s)> / (b), PDls (c) of the polymers in the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in p-xylene at 90°C. [MMA]o [initiator]o [metal salt]o [ligand]o = 150 1 1 2, MMA/p —xylene = l 2v/v. EBIB, MBP, BEB, and TsCl were used as initiator from right to left in each ligand column, respectively (Reprinted with permission from [34]. Copyright (2004) John Wiley Sons, Inc.)...

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