Benzyl methacrylate

CR-39 has been copolymerized with benzyl methacrylate and triaHyl cyanurate, also with benzyl methacrylate [2495-37-6] and diaHyl phthalate (24), and with trifluoroethyl methacrylate by a two-step process (25). 

Besides appHcation as heat-resistant molding powders for electronic and other appHcations, DAIP copolymers have been proposed for optical apphcations. Lenses of high impact resistance contain 50% DAIP, 20% benzyl methacrylate, and larger amounts of CR-39 (59). A lens of refractive index 71- = 1.569 andlow dispersion can be cast from phenyl methacrylate, DAIP, and isopropyl peroxide (60). Lenses of better impact properties can be obtained by modifying DAIP with aHyl benzoate (61). 

The results of this work are not limited to just S-b-MM and S-b-tBM, but may be extended to include styrene derivatives such as p-methylstyrene and p-t-butylstyrene 1). In addition to t-butyl methacrylate, other alkyl esters capable of stabilizing a carbonium ion, such as benzyl methacrylate and allyl methacrylate, should exhibit similar reactivity toward acidic hydrolysis and TMSI. In contrasting the hydrolysis of tBM blocks with TsOH and their reaction with TMSI, it should be noted that the hydrolysis is reportedly catalytic in nature (7-10), whereas the reaction with TMSI is stoichimetric. Therefore the latter approach may allow one to more easily "dial in" a desired level of methacrylic acid or metal methacrylate. 

TiCU readily functionalizes hydrophilic polymers such as poly(vinyl alcohol), m-ciesol novolac and methacrylic acid copolymers as well as moderately hydrophobic polymers such as poly(methyl methacrylate), poly(vinyl acetate), poly(benzyl methacrylate) and fully acetylated m-cresol novolac. HCI4 did not react with poly(styrene) to form etch resistant films indicating that very hydrophobic films follow a different reaction pathway. RBS analysis revealed that Ti is present only on the surface of hydrophilic and moderately hydrophobic polymer films, whereas it was found diffused through the entire thickness of the poly(styrene) films. The reaction pathways of hydrophilic and hydrophobic polymers with HCI4 are different because TiCl is hydrolysed by the surface water at the hydrophilic polymer surfaces to form an etch resistant T1O2 layer. Lack of such surface water in hydrophobic polymers explains the absence of a surface TiC>2 layer and the poor etching selectivities. 

Chart 2.6 Structure of block copolymer based on PEO and poly(benzyl methacrylate) (PBMA) containing /3-D-galactose unit. 

In addition to MMA, a variety of methacrylic esters were polymerized rapidly to the corresponding polymers with narrow MWDs in the presence of methylaluminum bis(2-ferf-butyl-4-methoxyphenolate) (3c). The successful examples include ethyl methacrylate (EMA), isopropyl methacrylate ( °PMA), n-butyl methacrylate ("BMA), isobutyl methacrylate ( °BMA), benzyl methacrylate (BnMA), and dodecyl methacrylate (Cj2MA), where the Mn values were all close to the predicted values (Mn j ) with the Mw/Mn ratios below 1.1 (Table 3, runs 1-4,6,7). The polymerization of ferf-butyl methacrylate ( BMA) is the only exception, where the monomer conversion hardly increased even after 24 h. 

Polymers of -Substituted Benzyl Methacrylates and Aliphatic Aldehydes as New Types of Electron-Beam Resists... 

In this article we will describe two different types of positive electron-beam resists, which were briefly reported in our previous communications (2,3). One is the homopolymer or copolymer with methyl methacrylate and a-substituted benzyl methacrylate, which forms methacrylic acid units in the polymer chain on exposure to an electron-beam and can be developed by using an alkaline solution developer. In this case, the structural change in the side group of the polymer effectively alters the solubility properties of the exposed polymer, and excellent contrast between the exposed and unexposed areas is obtained. The other is a self developing polyaldehyde resist, which is depolymerized into a volatile monomer upon electron-beam exposure. The sensitivity was extremely high without using any sensitizer. 

Materials. Benzyl methacrylate was obtained commercially. a-Methylbenzyl... 

Positive Electron-beam Resist of Poly (a-substituted Benzyl Methacrylate). The electron-beam resist behaviors of poly(a-substituted benzyl methacrylate)s are given in Table III. When the exposed resist films were developed with a mixture of MIBK and IPA, the sensitivities of these polymers were on the order of 10-4 C/cm2. When a dilute solution of sodium methoxide in methanol was used as a developer, the sensitivity was enhanced as compared with the former case, and increased with an increase in the bulkiness of the ester group of the polymer except for poly(a,a-diphenylethyl methacrylate). 

The results mentioned here clearly indicate that the enhancement in the sensitivity and 7-value of the poly (a,a-dimethyl benzyl methacrylate) resist over poly(methyl methacrylate) is mainly due to facilitated formation of methacrylic acid units on electron-beam exposure. The exposed area, which contains CH,... 

Then the decomposition is expected to be more favorable as the number of / -hydrogen atoms is larger. This is the case for the poly(a-substituted benzyl methacrylate)s as shown in Figure 7. However, when poly(t-butyl methacrylate) containing nine / -hydrogen atoms was exposed to an electron-beam, the amount of acid group formed was smaller than that for poly (a,a-... 

Some of the polymers slowly change their helicity in solution. A chiral crown ether-potassium ferf-butoxide combined system was reported to cause polymerization of methyl, tert-butyl, and benzyl methacrylate to form isotactic polymers that had high rotation values (164). Detailed scrutiny, however, raised questions about the result (135, 165). At first, in the presence of the initiator, the oligomers exhibit considerable activity, but after removal of the catalyst, the optical activity decreases. This decrease may be attributed to unwinding of the helixes in the chain the helicity could be caused by the anchored catalyst. 

The tacticity has been estimated by N. M. R. analysis also in the case of poly - (1 - methyl-benzyl) -methacrylate (64) obtained by different polymerization processes (Table 18). 

The experimental data obtained by several authors who polymerized, by radical processes, optically active para-sec.butyl-vinyl benzoate (73), ortho-vinyl-benzyl-sec.butylsulfide (98), 1.3-dimethyl-butyl-methacrylate (9), and (l-methyl-benzyl)-methacrylate (14), confirmed the theoretical forecast. In fact the polymers obtained after cleavage of the optically active groups did not show optical activity. The stereoregularity of the polymers has not been carefully checked up and the possible increase in stereoregularity, which was theoretically foreseen, has not been reported. 

In fact, the copolymers of methacrylic acid with maleic anhydride (14) and the copolymers of vinyl alcohol with maleic anhydride (127) obtained respectively from optically active (l-methyl-benzyl)-methacrylate or (l-methyl-benzyl)-vinyl-ether and maleic anhydride, were optically active, but their rotatory power was rather small. 

Figure 5. SNMS depth profiles for a series of methacrylate polymer/Z6040 (<5 =9.3)/Al laminates. Profile a is fora laminate in which polyfisobutyl methacrylate) (d =8.65) was the polymer. Profiles b, c, and d utilized polyfethyl methacrylate) (<5 = 8.95), poly (methyl methacrylate) (i=9.3), and poly(benzyl methacrylate) (d = 9.9) as the polymer, respectively.

The data on kp and kt as reported in the literature differ considerably. Therefore, we conducted new studies on methyl methacrylate (MMA), benzyl methacrylate (BMA), and styrene (St) as monomers. The constants were obtained by applying the method of intermittent illumination (rotating sector) combined with stationary state methods. The viscosity of the solvents varied between 0.5 and 100 cP. No mixed solvents composed of low- and high-molecular components were used but pure solvents only, the molecules of which did not deviate very much from a spherical form (methyl formate, diethyl phthalate, diethyl malonate, dimethyl glycol phthalate, etc.). 

This scheme does not hold for benzyl methacrylate and even less for styrene kt of these monomers is no longer inversely proportional to rj. Maybe the theory of the so-called inner viscosity can help (as developed by Kuhn and Kuhn around 1950). According to that theory, the movement of a segment in a solvent of viscosity rj8 is overlaid by an inner viscosity rjif so that... 

Helix-sense-selective polymerization of methyl, benzyl, and f-butyl methacrylates was attempted by using the complexes of chiral crown ethers, 91 and 92, and that of a chiral diamine 93 with n-BuLi however, these esters seem to be too small to form and maintain helical conformation [138,139], The complexes of BuLi with 58a and 59 failed in producing an optically active, helical polymer in the polymerization of methyl and benzyl methacrylates [104b]. 

---