Phenol, 4-vinyl

The first recent entries in this area stem from nucleopalladation reactions of 2-vinyl phenols. These reactions were independently discovered by Le Bras, Muzart and Sigman (Scheme 4.5). The former group described a reaction employing... 

Polymers of vinyl phenol are obtained by hydrolyzing polyacetoxystyrene [286,287]. The respective phenol salts can be used. The demulsifier is applicable to oil-in-water emulsions and does not require the use of zinc or other heavy metals. Therefore it does not cause the environmental problems inherent in such metals. 

R. S. Buriks, A. R. Fauke, and D. J. Poelker. Vinyl phenol polymers for demulsification of oil-in-water emulsions. Patent CA 2031122,1991. 

Monomer Synthesis. 4-Allyloxystyrene was prepared by the Wittig reaction of 4-allyloxybenzaldehyde and methyltriphenylphosphonium bromide, under basic conditions. The allyloxybenzaldehyde was prepared, in turn, by the alkylation of 4-hydroxybenzaldehyde with allyl bromide. This method, which provides high purity monomer in high overall yield, is outlined in Scheme 1 and has been previously described (2). Alternatively, the monomer may be prepared by the direct alkylation of p-vinylphenol with allyl bromide (8,9), although this method is less convenient due to the difficulties in synthesizing and storing the highly reactive vinyl phenol (10). 

Figure 1. Preparation of the copolymers of 4-vinylbenzyl acetate and 4-vinyl-phenol.

Dry salt grass, Distichlis stricta, has high levels of phenolics after fruiting. Cinnamic acids and their vinyl phenols lower uterus weight, inhibit follicular development, and lead to cessation of reproductive activity in the montane vole Microtus montanus. Specific active compounds are 4-vinylguaiacol and 4-vinylphenol, and alsop-coumaric acid (4-hydroxycinnamic acid) (Berger etal, 1977). 

Poly(vinyl Phenol) (PVPh) Used as a Proton-Donating Polymer. . 138... 

Among the proton-donating polymers used to study the complexation in non-aqueous media, poly(vinyl phenol) has been the most extensively used. Pearce s... 

Here, HPS stands for p-(2-hydroxyisopropyl)styrene, HES for p-(l-hydroxye-thyl)styrene, 4-VPh for 4-vinyl phenol, HFS for p-(hexafluoro-2-hydroxyisopro-pyl)styrene, and 4-VBA for 4-vinylbenzoic acid. Among these, 4-VBA has the lowest pKa and the highest K2, which implies that the carboxyl group has the strongest ability to form a dimer and to liberate its proton simultaneously. Thus, we can expect that CPS forms ring-like dimers and shows miscibility and complexation features intrinsically different from PS(OH), PS(t-OH), PS(s-OH) and STVPh. 

Materials. Epoxy novolac, DEN-431, obtained from Dow Chemical Co. was selected as the epoxy component. A 3,3 -diazidodiphenyl sulfone synthesized in our laboratory (5) was used as the azide compound. Poly(/7-vinyl phenol) obtained from Maruzen Oil Co. was used as the phenolic resin matrix. The coating solvent was cyclohexanone. The developer used in this study was 0.1 N tetramethylammonium hydroxide aqueous solution. 

Vacuum Curing Effect. In the early stage of this work, we investigated a mixture of epoxy novolac and poly(p-vinyl phenol) (EP) to obtain an electron beam sensitive non-swelling resist. Epoxy novolac was chosen as the sensitizing component, because epoxy groups are known to be electron-beam-sensitive substituents (2). However, it is also known that electron beam resists... 

Exposure-induced Reaction Products. Gel permeation chromatograms of EP, MRS, and EAP were measured before and after exposure at 20 /uC/cm2. The results are summerized in Figures 8 to 10. In the case of EP resist, shown in Figure 8, peaks 1, 2, and 3 represent epoxy novolac dimer, trimer, and tetramer, respectively. Peak 4 represents the main component of the poly(p-vinyl phenol) resin and peak 5 indicates the presence of exposure-induced high molecular weight components in the resin. 

The gel permeation chromatograms of MRS are shown in Figure 9, where peaks 1 and 2 represent the azide compound and the main component of poly(p-vinyl phenol), respectively. Peak 3 corresponds to a primary amine, which is one of the exposure-induced reaction products from the azide compound (14). Peak 4 indicates the same exposure-induced high molecular weight components as for EP. 

In general, a high-molecular-weight phenolic resin is less alkaline-soluble than a low-molecular-weight one. Therefore, these high molecular weight poly(p-vinyl phenol) components may contribute to the decrease in solubility. Furthermore, we assume that the etching type dissolution of these resists is non-fractional, as was previously shown in the case of poly (methyl methacrylate-co-acrylonitrile) (15). 

Several important types of adhesives used to obtain high-strength bonds are the epoxies, epoxy -phenolics, nitrile-phenolics vinyl-phenolics... 

The information obtained from the detector is used to generate the mass spectrum. The mass spectrum is a plot of the intensity of the individual mass-analyzed ions plotted as a function of m/z. Usually the most intense ion, termed the base peak, is given a relative abundance of 100% and the rest of the ions in the mass spectrum are normalized to this intensity. Figure 5.1 shows the El mass spectrum of 2-methoxy-4-vinyl phenol (molecular weight 150 Daltons). The base peak is the molecular ion at m/z 150, a radical... 

Many of the applications in which CEs are involved require clarity or uniform properties on a microscopic structural level, so miscibility or molecular-scale mixing is important when CE-based blends are formed. There are some examples of miscible or homogeneous CE blends with vinyl polymers. One interesting class of these is a mixture of CE and poly(vinyl phenol) (PVPh) [101,102], This phenolic polymer is known to form a miscible blend with a wide variety of polymers with potential hydrogen-bond-accepting groups [101], the latter set including commercially available CEs, i.e., cel-... 

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