Methyl methacrylate, copolymerization with

AH-acryHc (100%) latex emulsions are commonly recognized as the most durable paints for exterior use. Exterior grades are usuaHy copolymers of methyl methacrylate with butyl acrylate or 2-ethyIhexyl acrylate (see Acrylic ester polymers). Interior grades are based on methyl methacrylate copolymerized with butyl acrylate or ethyl acrylate. AcryHc latex emulsions are not commonly used in interior flat paints because these paints typicaHy do not require the kind of performance characteristics that acryHcs offer. However, for interior semigloss or gloss paints, aH-acryHc polymers and acryHc copolymers are used almost exclusively due to their exceUent gloss potential, adhesion characteristics, as weU as block and print resistance. 

By means of the spatially intermittent reactor, Ito and O Driscoll determined, for example, the absolute rate constant of termination, fct, for methyl methacrylate copolymerization with butyl or dodecyl methacrylate. The value of /ct is a function of the monomer mixture composition [89]. 

MA Diels-Alder adducts, 118, 119, 158, 159 MA ene reaction, 119, 158, 159 MA equimolar copolymerization, 270, 273 MA-metal complex polymerization, 212 maleate and fumarate copolymerization, 365, 369 maleimide copolymerization, 266, 365 MA nonequimolar copolymerization, 270-298 MA reactivity ratios, 302 methyl methacrylate copolymerization with MA CTC, 370... 

One of the first detailed studies on these systems was that of Beaman (26), who showed that methacrylonitrile polymerizes by an anionic chain mechanism when treated with various bases, including Na in liquid ammonia at —75° C. He noted also that low molecular weight polymers are obtained from reaction of acrylonitrile with butylmagnesium bromide. Foster (56) extended the liquid ammonia method to copolymerization studies in which acrylonitrile was combined with styrene, with methyl methacrylate and with vinyl butyl sulfone. Satisfactory data were obtained only with the sulfone, in which case there was some tendency for alternation. 

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. 

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 .]... 

In the end of 1960s, Nikolaev et al.29 and Ito et al.30 independently demonstrated an appreciable effect of the reaction medium on the reactivity ratios in the copolymerization of methyl methacrylate and styrene (Table 19). Ito et al. found that the relative reactivity of methyl methacrylate toward the polystyryl radical is correlated with the transition energies ET for the longest wavelength absorption band for pyridinum TV-phenolbetaine in solvents. They suggested that the polarized structure of methyl methacrylate monomer becomes important in the transition state. Bonta et al.32 also demonstrated that there is an appreciable solvent effect on the reactivity ratio in the styrene-methyl methacrylate copolymerization in non-... 

Table 17. Monomer reactivity ratios in the copolymerization of methyl methacrylate(Mj) with various methacrylates(M2) by BuLi in toluene and in tetrahydrofuran at -78 C, Ref. ...

Table 19. Copolymerization of methyl methacrylate(Mi) with methacrylatefMj) of tertiary alcohol by BuLi in toluene... 

Similarly the coisotactic parameters were obtained in the copolymerizations between methyl methacrylate(Mi) with other methacrylates(M2), and between OK-methylbenzyl methacrylate(Mi) with trityl methacrylate(M2) by radical and BuLi initiators in THF. The parameters are shown in Table 20. 

Table22-14. Copolymerization Rates, Vp, Rate Constantsfor Propagation, kp, and Factors for the Free Radical Copolymerization of Methyl Methacrylate (M) with...

Table 22-16. Influence of Various Initiators on the Coplymerization Parameters for the Copolymerization of Methyl Methacrylate (M) with Acrylonitrile (A)...

The preparation of natural rubber-gra/t-methyl methacrylic acid has been reported by Lenka and coworkers. The vanadium ion was used as an initiator, which initiated the creation of free radicals on the backbone of natural rubber and this increased the interaction between the natural rubber and the methyl methacrylate surfaces. The coordination complexes derived from the acetylacetonate of Mn(III) ions could also be used as an initiator to form the natural rubber-gra/t-methyl methacrylic acid. Under different conditions, silver ions could be used as a catalyst to produce natural rubber-gra/t-methyl methacrylic acid with different concentrations of methyl methacrylic acid monomers, and potassium peroxydisulfate as an initiator. Consequently, these methods were successful in the preparation of compatible blended natural rubber and methyl methacrylic acid by graft copolymerization. This compatibility was confirmed by nuclear magnetic resonance and infrared spectroscopy techniques. The interaction between natural rubber and methyl methacrylic acid was significantly increased and was useful for further blending with other polyacrylate molecules or different polymer types. 

Vinyl ethers copolymerize with methyl methacrylate to give alternating copolymer units as well as homopolymer segments of methyl methacrylate [35]. With other monomers this is also true, and either solution, emulsion, suspension, or bulk polymerization techniques may be used. The pH should be kept at about 8 or above in aqueous systems to prevent hydrolysis of the vinyl ether. The / 2 (alkyl vinyl ether) values are low and approach zero for bulk polymerization systems [36-38] utilizing such monomers... 

In a similar way, graft copolymers have been synthesized by reaction of a polyurethane carrying an isocyanate function at the chain end with a poly(methyl methacrylate) backbone with some pendant OH functions, the latter species being obtained by free radical copolymerization of MMA with some hydroxyethyl methacrylate. 

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