Acrylic acid, moieties

As far as neighboring group inhibition is concerned, sequence distribution can play an important role, e.g. Morowetz [5] showed that partially hydrolyzed polyacrylamide hydrolyzes more slowly than an acrylic acid copolymer of the same charge. The former has a more even distribution of groups leading to a greater proportion of the least reactive BAB triad (where A are the acrylamide and B are the acrylic acid moieties). 

These polar copolyr ers are more transparent and. as a result of the presence of the polar acrylic acid moiety, have better adhesion to metallic surfaces than ldpb. The commercial copolymer, which is usually 50% neutralized to salts of sodium or zinc, is stiff and strong because of ionic crosslinking at room temperature, but it is readily proccssible when heated. 

The stability of superabsorbent polymers against UV irradiation was evaluated by measuring the decrease of viscosity of swollen gels of poly (acrylate). In Fig. 9, the changes of the retention of the viscosity of the polymer gels UV-irradiated as a function of the degree of neutralization of acrylic acid moiety in crosslinked poly(acrylic acids) with alkali are shown. 

An entirely new approach to the synthesis of ellipticine (267) has been reported by Kozikowski and Havan (315). Crucial in this synthesis is the Diels-Alder addition of an acrylic acid moiety to an oxazole followed by elimination of the oxygen bridge to give a pyridine. Thus, heating the oxazole 738 in acetic acid-acrylonitrile at 145° gave the indolyl-ethyl pyridine 739 in 16% yield (Scheme 59). The iV-acetyl derivative of this intermediate had previously been converted to 267 (266). 

A catalyst, which catalyzes the esterification reactions between the OH end groups of PPE and the COOH groups of the pendent acrylic acid moieties, is magnesium acetate tetrahydrate. 

Using the results of previous studies of palladium- and platinum-catalyzed hydroarylation of alkynes (Fig. 26A), Kitamura and coworkers extended this chemistry to functionahze PS and polystyrene-l)/ocfe-poly(ethylene-ra -butylene)-l>/ocfe-polystyrene (SEES) with acrylic acid moieties (Fig. 26B). Reactions of PS with propionic acid or methyl ester in the presence of K2PtCl4 and Ag(CF3S03) afforded maximums of 7% and 30% alkenylated styrene unit for PS and SEES, respectively. Although... 

If PAANa and POE were miscible, single ion conduction would be possible because anions would be fixed to the polymer matrix. Since PAANa and POE, however, were not miscible in the solid state, acrylic acid moieties were introduced to PAANa for the purpose of the partial complexation through hydrogen bonding. In the experiment, the glass transition temperature and ionic conductivity were studied for PAANa-PAA-POE composite films having different neutralization of PAA and different incorporation of POE. 

The key step in the total synthesis of rhizobitoxine is the Pd-catalyzed exchange reaction of the methyl alkenyl ether moiety in 4 with the functionalized alcohol, although the yield is low[3]. The enol pyruvate 6 (a-ethoxyacrylic acid) is prepared by the reaction of methyl a-methoxyacrylate or a-methoxy-acrylic acid (5) with ethanol catalyzed by PdCl2(PhCN)2 at room temperature in the presence of CuCli and NaH2P04[4],... 

Shimidzu etal.111 studied the catalytic activity of poly (4(5)-vinylimidazole-co-acrylic add) 60 (PVIm AA) in hydrolyses of 3-acetoxy-N-trimethylanilinium iodide 61 (ANTI) and p-nitrophenylacetate 44 (PNPA). The hydrolyses of ANTI followed the Michaelis-Menten-type kinetics, and that of PNPA followed the second-order kinetics. Substrate-binding with the copolymer was strongest at an imidazole content of 30 mol%. The authors concluded that the carboxylic acid moiety not... 

Solutions of different carboxylic acids (fiimaric acid [FA], maleic acid, acrylic acid, succinic acid, and malonic acid) in ethanol have been effectively used as primers to increase the adhesion of synthetic vulcanized SBRs. The increase in the adhesion properties of SBR treated with carboxylic acid is attributed to the elimination of zinc stearate moieties and the deposition of acid on the rubber which migrates into the solvent-borne polyurethane adhesive layer once the adhesive joint is formed. The nature of the carboxylic acid determines the rate of diffusion into the adhesive and the extent of rubber-adhesive interfacial interaction. 

Although the Heck reactions of heteroaryl halides are now commonplace [76], few examples are found using organohalide substrates possessing a carboxylic acid moiety [77]. However, 4,5-dibromo-2-furancarboxylic acid (86) underwent a Heck reaction with ethyl acrylate to afford diacrylate 87 [78]. 

The resulting acrylic acid/N-(hydroxyalky1) acrylamide copolymers were evaluated for their deposit control and dispersant activities as compared to the homopolymer of acrylic acid. Differences in the activities could be attributed to the incorporation of the N-hydroxylalkylacrylamide moiety into the polymer chain. 

An alternative photo-SIP approach was described by Kang and coworkers, where they used an argon plasma to oxidize alkylthiolate SAMs on planar gold [55]. The plasma treatment oxidized carboxy-terminated SAMs to peroxide moieties. UV irradiation in the presence of acryhc acid and allylpentafluorobenzene yielded ultra-thin graft layers of 6-7nm. The poly(acrylic acid) layers were found to adsorb Fe " ions from solution. This particular photoinitiation method yields low-density polymer brush films. 

The Michael attack of the enamine moiety in the 3,6-dihydro-2//-l,3-thiazine 149 on a-phthalimido acrylic acid affords the cyclic product 152, most probably through the intermediate 150. Support for the mechanisms comes from the isolation of the 5,6,7,8-tetrahydro-la//-thiireno[2,3-f]indolizine 151 in 10% yield (Scheme 10) <1999J(P1)3565>. 

If the starting A -acylamino acid contains a leaving group in the acyl group moiety then hydrolysis of the corresponding oxazolone 445 generates an acrylic acid derivative such as 446. Treatment of 446 with ammonia then produces glycyl-... 

The carboxylic acid moieties of the poly(acrylate) are also involved in the inhibition of proteolytic enzymes. Divalent cations are necessary for many proteases to act, specifically Ca2+ and Zn2+. Whether these polymers can be effective in vivo at protecting peptides has been of some concern (Bemkop-Schnurch and Gockel... 

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