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The common strongly basic Type I anion exchange resins, magnified image contain benzylictrimethylammonium groups. In OH− form, the resins are unstable above 60°C. due to nucleophilic attack by OH− on the benzylic and methyl carbon atoms. Reactivity of benzylic carbon sites relative to methyl sites is about 4 to 1. More stable resins would be desirable, so laboratory synthesis and stability study was made of a resin which contained neither benzylic carbon atoms nor β‐carbon atoms having hydrogen atoms which could give elimination reactions. This resin, magnified image containing neophyltrimethylammonium groups, nevertheless lost strong base capacity more readily than a comparative resin containing benzylic trimethylammonium groups. The breakdown was primarily at the methyl carbon atoms, however, so almost all weak base capacity was retained. The greater reactivity of methyl groups on the neophyl resin—relative to methyl groups on benzylic resin—can be due to internal compressional strain between the methyl groups of the nitrogen and the methyl groups of the β‐carbons.

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SynopsisAlthough sulfonium salts are well known, polymeric sulfonium salts seldom have been mentioned in the chemical literature. This paper describes exploratory work in the preparation of various sulfonium monomers and polymers from ar-vinylbenzyl chlorides (ortho and para isomers). These chlorides-particularly the para isomer-reacted readily with 2,2'-thiodiethanol and water to yield the corresponding ar-vinylbenzyl sulfonium chloride monomers in aqueons solution.The odorless, reactive monomer mixture polymerized readily with persulfate or hydroperoxide catalysts; however, polymerization could be inhibited with cupric salts. Copolymerization with trimethyl(ar-viny1benzyl)ammonium chloride was random. In copolymerization with acrylamide or acrylonitrile, the sulfonium monomer was more reactive. Analogous sulfonium monomers were made by reaction of ar-vinylbenzyl chlorides with various sulfides. In general, all the sulfonium monomers yielded homopolymers which were fairly stable in aqueous solution in the absence of strongly nucleophilic agents which would attack the sulfonium groups. However, when dried a t room temperature the polymers would crosslink; and when heated, the polymers became hydrophobic also. Scrambling of the sulfonium group substituents during drying, and nucleophilic displacement reactions by chloride ion during heating were likely explanations. The high cationic charge on the polymers made them substantive to cellulose fibers. This property, when coupled with high nucleophilic reactivity of the sulfonium groups with the carboxylate sites of the pulp or other anionic counterions during drying and heating, made the polymers very effective as beater additives for imparting wet strength to paper.

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