Methacrylonitrile methacrylate

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]. 

Materials containing the above structure in the polymer chain may be made from copolymers of methacrylic acid and methacrylonitrile. Ammonia-producing additives (such as urea and ammonium hydrogen carbonate) are added to the... 

One disadvantage of this process is the waste NH4HSO4 stream. Methacrylic acid (MAA) is also produced by the air oxidation of isobutylene or the ammoxidation of isobutylene to methacrylonitrile followed by hydrolysis. These reactions are noted in Chapter 9. 

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. 

Complexes (181)-(183) may also be used to polymerize acrylates449 and methacrylonitrile450 in a living manner, although (181) again requires photoinitiation. Acrylates such as BuA polymerize faster than methacrylates. The rate of propagation of methacrylonitrile is much slower than methacrylates, although in the presence of (185), 100 equivalents are consumed within 3 hours. 

Block copolymerization was carried out in the bulk polymerization of St using 18 as the polymeric iniferter. The block copolymer was isolated with 63-72 % yield by solvent extraction. In contrast with the polymerization of MMA with 6, the St polymerization with 18 as the polymeric iniferter does not proceed via the livingradical polymerization mechanism,because the co-chain end of the block copolymer 19 in Eq. (22) has the penta-substituted ethane structure, of which the C-C bond will dissociate less frequently than the C-C bond of hexa-substituted ethanes, e.g., the co-chain end of 18. This result agrees with the fact that the polymerization of St with 6 does not proceed through a living radical polymerization mechanism. Therefore, 18 is suitably used for the block copolymerization of 1,1-diubstituted ethylenes such as methacrylonitrile and alkyl methacrylates [83]. 

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. 

The effect of varying the concentration of the 3-oximino-2-butanone methacrylate moiety was studied next. From the above results, it appears that the optimum nitrile concentration is roughly 15 to 22%. We chose to fix the methacrylonitrile mole fraction at the lower value in order to least perturb the solubility characteristics of the polymer. 

The photosensitivity of PMMA is significantly enhanced by the incorporation of 10 to 40 mole% 3-oximino-2-butanone methacrylate. Terpolymerization with methacrylonitrile increases that sensitivity still further, P(M-OM-CN) (69 16 15) being 85 times more sensitive than PMMA on exposure to the full output of a 1000 watt mercury lamp. Upon addition of external sensitizers, this sensitivity may be increased by an additional factor of 2 to 3. The high resolution characteristics of PMMA have been retained and the polymers in question show good plasma resistance. 

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.

C02CH2CH(CH3)2 - poly(Isobutyl methacrylate) (PIBM) C02C(CH3)3- poly(tert-butyl methacrylate) (PTBM) CO2CH2CCI3- poly(trichloroethyl methacrylate) (PTCEM) CO2CH2CF2 poly(trifluoroethyl methacrylate) (PTFEM) C02CH(CF3)2 poly(hexafluoroisopropyl methacrylate)(PHFIM) CN - poly(methacrylonitrile)(PMCN)... 

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