Methacrylonitrile-methyl Methacrylate

San Roman and co-workers [161] studied the microstructure and stereochemical configuration of methacrylonitrile (N), methyl methacrylate (M), copolymers prepared by free-radical polymerisation at 60 C on the basis of the classical terminal copolymerisation model and with the assumption of Bernoullian statistics for the 

Reprinted with permission from G.S. Kapur and A.S. Brar, Journal of Polymer Science Part A Polymer Chemistry, 1991, 29, 4, 479. 1991, John Wiley [179]  

The molar fractions of tactic M-centred triads, independent of the chemical structure, M or N, of neighbouring units of copolymer samples with different compositions (N = mole fraction of methyacrylonitrile) are collected in Table 7.14. 

Values calculated have been obtained with the copolymerisation parameters indicated in the text. Mole fraction of methacrylonitrile Reprinted with permission from ]. San Roman, B. Vazquez, M. Valero and G.M. Guzman, Macromolecules, 1991, 24, 23, 6089. 1991, ACS [161]  

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In a practical sense the hydrocarbon monomers that work best in anionic systems are styrene, a-methylstyrene, p-(tert-butyl)styrene, butadiene, isoprene, 2,3-dimethyIbutadiene, piperylene, stilbene, and 1,1-diphenylethylene. The latter two monomers give rise to alternating copolymers with other dienes but do not homopolymerize. Among the polar monomers (C) that can be polymerized are such monomers as 2-vinyIpyridine, pivalolactone, methacrylonitrile, methyl-methacrylate, ethylene oxide (not with Li-counterion), ethylene sulfide, and propylene sulfide. However, polymerization of many of these polar monomers suffers from side reactions and complicating termination or transfer reactions not present in the... 

Butyl alcohol is employed as a feedstock in Japan to make methyl methacrylate monomer. In one such process (26), the alcohol is oxidized (in two steps) to acryHc acid, which is then esterified with methanol. In a similar process (27), /-butyl alcohol is oxidized in the presence of ammonia to give methacrylonitrile [126-98-7]. The latter is hydrolyzed to methacrjiamide [79-39-0] which then reacts with methanol to yield methyl methacrylate [80-62-6]. 

COCH3 >—CN >—COOR >—Cl >—CH2Y >—OCOCH3 >—OR. The effect of a second 1-substituent is roughly additive. 2-Chlorobutadiene and 2,3-dichlorobutadiene [not included in Table XX] are the most reactive monomers examined. A methyl group usually increases reactivity (methyl methacrylate >methyl acrylate, methacrylonitrile > acrylonitrile, methal-lyl>allyl derivatives) and two chlorine atoms are nearly as effective as a carbalkoxy group. 

The low reactivity of a-olefins such as propylene or of 1,1-dialkyl olefins such as isobutylene toward radical polymerization is probably a consequence of degradative chain transfer with the allylic hydrogens. It should be pointed out, however, that other monomers such as methyl methacrylate and methacrylonitrile, which also contain allylic C—H bonds, do not undergo extensive degradative chain transfer. This is due to the lowered reactivity of the propagating radicals in these monomers. The ester and nitrile substituents stabilize the radicals and decrease their reactivity toward transfer. Simultaneously the reactivity of the monomer toward propagation is enhanced. These monomers, unlike the a-olefins and 1,1-dialkyl olefins, yield high polymers in radical polymerizations. 

Poly(methyl methacrylate-co-3-oximino-2-butanone methacrylate-co-methacrylonitrile)... 

Poly(methyl methacryIate-co-3-oximino-2-butanone methacrylate) (P(M-OM) and poly(methyl methacrylate-co-3-oximino-2-butanone-methacrylate-co-methacrylonitrile) (P(M-OM-CN)) were dissolved in methoxyethyl acetate (10% solution). Where appropriate, the specified amount of sensitizer was added to the solutions before coating onto a silicon substrate with a Headway Research spinner. Films were prebaked at 120 C for 60 min. 

The incorporation of small percentages (<10%) of 3-oximino-2-butanone methacrylate (4) into poly(methyl methacrylate) (PMMA) (Scheme I) results in a four fold increase in polymer sensitivity in the range of 230-260 nm flO.l 11. Presumably, the moderately labile N-O bond is induced to cleave, leading to decarboxylation and main chain scission (Scheme II). The sensitivity is further enhanced by the addition of external sensitizers. Also, preliminary results indicated that terpolymerization with methacrylonitrile would effect an additional increase. These results complement those of Stillwagon (12) who had previously shown that copolymerization of methyl methacrylate with methacrylonitrile increased the polymer s sensitivity to electron beam irradiation. The mole fraction of the comonomers was kept low in order to insure retention of the high resolution properties of PMMA (3.41. 

In an effort to improve PMMA s photosensitivity further, methyl methacrylate has been copolymerized with higher percentages of the a-keto-oxime methacrylate and terpolymerized with varying amounts of methacrylonitrile. The resulting effects on resist properties, e.g., sensitivity, contrast and resolution, and plasma resistance, are reported here. The terpolymers are up to 85 times more sensitive than PMMA, and retain its high resolution characteristics. 

Figure 2 shows survey Raman spectra of the hcmopolymers, poly(methyl methacrylate)(PMMA.), poly(3-oximino-2-hutannone methacrylate)(pom), and poly(methacrylonitrile)(PMAN), and one terpolymer(P(M-0M-CN)) with a S/N ratio of about 10 1. Each of the polymers has a band specific to that polymer 8l2 dcm-1 (vg (C-O-C) for IMMA), 1622 hem" (Vg(C=N) for POM), and 2237 dcm l(vg(CHN) for PMAN). Additionally, there is an asymmetric C-H bending mode at 1 53 Acm l, common to all three homopolymers, which serves as an internal standard. These bands are indicated by arrows in Figure 2. A broad fluorescence background is evident, but it can be reduced to acceptable levels by exposure to high laser power for 10-30 minutes, depending on the sample. Residual background fluorescence may be due to the oximino chromophore itself. Figure 3 depicts an example of actual data for a 75 15 10 terpolymer with a S/N ratio of about 50 1.

In the present section we describe the living anionic polymerization of meth-acrylonitrile by two initiating systems such as the aluminum porphyrin-Lewis acid system and the aluminum porphyrin-Lewis base system which enables the synthesis of poly(methyl methacrylate-h-methacrylonitrile)s of controlled molecular weights. 

Table 7. Block copolymerization of methacrylonitrile (MAN) with the living prepolymer of methyl methacrylate (MMA) (2) in the presence of methylaluminum bis(2,6-di-ferf-butyl-4-methylphenolate) (3e) ... 

Fig. 25. Polymerization of methacrylonitrile (MAN) with the living prepolymer of methyl methacrylate (MMA) (2)-pyridine system [2]q=20.7 mM, CH2CI2 as solvent, rt, [MAN]q/ [2]o=100, [pyridine]o/[2]o=0.6 ( , ), 10 ( , O), under diffuse light ( , ), under irradiation of visible light (> >420 nm) ( , O). Time-conversion relationship...

The fact that allyltributyltin and styrene which are electroneutral were successfully added to PCTFE led us to the question "Can electron-rich or electron-poor trapping agents be used ". The electron-rich agents that we examined were ethyl ethynyl ether and ethyl vinyl ether. On the side of the electron-poor alkenes, eight were investigated ethyl acrylate, methyl methacrylate, methyl vinyl ketone, acrylonitrile, methacrylonitrile, vinyl bromide, chloromethyl styrene, and 4-vinylpyridine. The details of each reaction are summarized. 

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. 

Wooding and Higginson (94) have polymerized acrylonitrile, methyl methacrylate, styrene and butadiene with a wide variety of alkoxides and other basic materials. The ease of polymerization of monomer is in the above mentioned order. A further study of the polymerization of acrylonitrile by Zilka, Feit, and Frankel using alkoxides has also been reported (104). These workers also studied the polymerization of acrylonitrile and methacrylonitrile in dimethyl-formamide by aqueous quaternary ammonium hydroxides (106). 

Fig. 25a, b. Correlation between transparency and calculated [6, 201] dispersion erf (1) x 103 of composition distribution of terpolymer molecules, prepared at complete conversion, for the reference i-th monomer in the system (acrylonitrile + a-methylstyrene + styrene) (a) and (methyl methacrylate + methacrylonitrile + styrene (b). Open and dark circles denote transparent and turbid terpolymeriza-tion products in the experiments by Slocombe [128]... 

Photochemical cycloaddition of 2-arylisoindoline-l-thiones 8 to electron-poor alkenes 9, such as methacrylonitrile, 2-butene-2-nitrile and methyl methacrylate, affords the corresponding tricyclic isoindolines 10 as two diastereomers143. 

Methyl methacrylate (Fig. 1-4) and methacrylonitrile (6-5) are allylic-type monomers that do yield high molecular weight polymers in free radical reactions. This is probably because the propagating radicals are conjugated with and stabilized to some extent by the ester and nitrile substituents. The macroradicals are... 

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