Carboxylate resin

The Surlyn A ionomers (E. I. du Pont de Nemours Co.) are believed to be derived from copolymers of ethylene with minor amounts of methacrylic acid which are treated subsequently, so that substantial amounts of the carboxylic acid are converted to the sodium or other metal carboxylate. Resins similar to the one studied in this work contain about 10 weight % methacrylic acid. The ash (sodium carbonate) indicates about 40% neutralization. This resin, which contains 0.05% Santo-white Powder (Monsanto Chemical Co.), a phenolic antioxidant, is of medium molecular weight—i.e., probably corresponding to an ethylene homopolymer with a melt flow index around 20 (17). The molecular weight distribution is broad (17). 

It is well known that homogeneous compounds of Mo(VI) with carboxylic acids are powerful catalysts for the epoxidation of olefins. In order to heterogenize the Mo(VI) derivatives, a commercial carboxylated resins has been used by Ivanov et al. (ref. 1). A weak point of using a commercial resin is that it is not possible to control the number and distribution of carboxylic groups. This results in a poor flexibility of structure and properties of the final catalyst. 

Water-Based Inks. Approximately 50% of all flexographic inks use water as their primary solvent and diluent. They contain vehicles based on either acrylic emulsions, or hydrosols or an alkali-soluble rosin ester having a high acid number such as partially esterified fiimurated rosin and shellac. Carboxylated acrylic polymers, usually containing some styrene, have largely replaced natural resins because they provide better abrasion and water resistance. Ammonia or other volatile amines are used to solubilize these carboxylated resins and form resin salts. The volatile alkali evaporates from the ink film, rendering the printed matter water resistant. 

A quite useful resin in nucleophilic carbon-carbon bond formation reactions is the carboxylic resin (5). The soft metal from the nucleophile is... 

Finally, an example of solid support reaction quenching [133] is reported in Figure 7.18. Six aldehydes were reacted with allylmagnesium chloride or with -butyllithium to produce reactive alkoxides in solution. They were quenched by the carboxylic resin 4, which also scavenged the excess of the... 

Diaryl tellurium dicarboxylates were prepared in good yields from diaryl tellurium dichlorides and anion exchange resins such as Amberlite IR45 and Amberlite IR400 in their carboxylate form. The carboxylate resins were obtained by treating the resins in the OHe-form with carboxylic acids or the resins in the Cle-form with sodium carboxylates4. 

TLC is more sensitive than IR spectroscopy in detecting small amounts of resin acids because it is a separation technique, but it cannot identify pine resins that have been completely decarboxylated. However, completely de-carboxylated resins are rare (two of 31 samples in the present study), and TLC can be used also for the rapid and inexpensive screening of large numbers of specimens with a reliability of >90%. 

Inhibition of the coordinating molybdenum centre by chemisorpiion of the reaction products normally accounts for the observed evolution of the reaction rates. The rates of deactivation of Mo-fixed catalysts have been varied considerably by varying the density and the acid strength of OH groups ol the support surface. The fixed catalysts have been synthesized molecularly by taking advantage of the ready reaction between molybdic acid and differently functionalized polymeric matrixes such as boronic,phosphonic and carboxylic resins. 

Some physical correlations with the catalytic activity of Mo(VI)-grafted carboxylated resins used as epoxidation catalysts... 

Figure 9 illustrates better the influence of pH and molecular structure on the adsorption of 5-triazines by clay and organic matter. Maximum adsorption occurred near the pKa of each compound, suggesting that basicity was a significant factor in their adsorbability by particulate matter. Adsorption of other basic molecules by cation exchange adsorbents, including atrazine by a carboxyl resin (118), amitrole by mont-morillonite (84) and organic matter (83), and purines and pyrimidines by montmorillonite (119), exhibit similar responses. 

Complexation of metal ions with the carboxyl resin Complexation of the carboxyl resin was carried out towards Fe(II), Fe(III), Co(II), Ni(II) and Cu(II) ions by a batch equilibration technique. A quantity (100 mg) of the resin was stirred in an aqueous metal salt solution (0.05 mol L , 50 mL) for 24 h. The complexed resins were collected by filtration and washed with distilled water to remove uncomplexed metal ions. The concentrations of the metal salt solutions were estimated by UV spectrophotometric methods. 

Nafion Sulfonate Resin Nafion Carboxylate Resin... 

Epoxycycl ohexy I methyl-3,4-epoxycyclohexane carboxylate resin, lacquers... 

It should be noted that a hydroxymethylated insoluble support was prepared through copolymerization of 4-hydroxymethylstyrene, styrene and divinylbenzene and also via the reduction of a carboxyl-resin with LiAlH4 by Letsinger and his associates (1963), who simultaneously and independently from Merrifield initiated solid phase peptide synthesis. In their approach the polymer was treated with phosgene and the polymeric analog of benzyl chlorocarbonate thus obtained used for the acylation of an amino acid ... 

It is customary to use a weak acid ion-exchange resin in the sodium form (e.g., a polyactylic carboxylic resin) artd regenerate with hydrochloric acid. Neomycin, a related antibiotic, is also recovered with a carboxylic acid ion exchanger. However, since the basic amine groups in neomycin are considerably weaker... 

Modern materials (e.g. Nafion 901) make use of the best features of both materials, see Figure 7. Most of the membrane is fabricated from the sulphonate resin to obtain the low resistance but the catholyte surface is coated with a thin film of carboxylate resin which permits the high caustic soda concentration to be produced. The plastic net gives the membrane additional mechanical and physical strength. 

The actual merit of employing the reaction between the sodium salt of poly(acrylic acid), PANa, and the uranyl ion as a model for uranyl capture by carboxylic resin is debatable. PANa permits flexible chain interactions with the uranyl ion, whereas the carboxylic resins present largely inflexible reaction sites where the matrix can capture the relatively uranyl... 

B. Softeniag (carbonate removal) on carboxylic resin for all or part of the make up as shown in the principal reactions below ... 

Saxitoxin (1) was the first toxin brought to a pure form (20). The purification procedure was based upon the toxin s ability to bind tightly to weakly acidic resins. A single chromatography on a carboxylate resin such as Amberlite IRC-50 was capable of raising the specific toxicity of the extract several hundred times. Repeated chromatography on carboxylate resins and subsequent chromatography on acidic alumina afforded pure saxitoxin as an amorphous dihydrochloride. 

---