Vinylpyridinium salts, polymerization

V.A. Kavanov, Polymerization of chemically-activated monomers, Pure Appl. Chem., 1967, 15, 391 VA. Kavanov, K.V Aliev, O.V Kargina, T.I. Patrikeeva, VA. Kargin, Specific polymerization of vinylpyridinium salts. Polymerization on macromolecular matrix, J. Polym. Sci., Part C, 1967, 16, 1079 O.V Kargina, VA. Kavanov and VA. Kargin, Polymerisation de la 4-vinylpiridine sur les matrices polyacides, J. Polym. Sci., Part C, 1968, 22, 339. 

The spontaneous polymerization in aqueous solution experienced in this polymer system is not unique to quarternary systems. Salomone (15) extensively studied the spontaneous polymerization of 4-vinylpyridinium salts. Although there are several similarities in the two systems, it appears that the initiating species may be different and will be the subject of future studies. 

PQ2+/PQ"+ was 69, 9, 1, 0 respectively. For all these processes at least 50% of the initial PQ + is recovered as PQ2+ and the remainder appears as a polymeric pyridinium salt, very similar to that formed by reactions of Ar2COII with PO + (Hyde and Ledwith, 1974b). Interestingly the proposed intermediate vinylpyridinium salts [60] may arise equally well from addition of (H+) to PO, or by addition of (H ) to PO +. 

According to Mielke and Ringsdorf, - polymerization of 4-vinylpyridinium salts in aqueous solution may give either the vinyl (1,2) polymer or an ionene polymer according to the conditions free radical polymerization is also possible. Klein favoured a mechanism of the Kabanov type for the spontaneous polymerization of 2-vinylpyridine in the presence of poly(methacrylic acid). 

Vinylpyridinium salts (nitrate, perchlorate, hydrogen sulfate) polymerize in solution spontaneously without the addition of initiator. In diluted systems the following reaction was observed [601]. 

In contrast to the other 4-vinylpyridinium salts, 4-vinylpyridinium trillates can only be polymerized by means of an initiator or spontaneously at by heating to 120 125 °C. This opens up a synthetic route to poly(4-vinylpyridinium) block copolymers [603 05]. 

The polymerization of the vinylpyridines, which occurs slowly at room temperature and more rapidly on heating, and their copolymeiization with other monomers is of technical importance in the production of synthetic fibres, synthetic rubbers, polyelectrolytes and other valuable substances. The presence of the nitrogen atom makes possible quaternizations to give products with properties different from those arising from purely carbocyclic residues " . The polymerization of 1-vinylpyridinium salts has also been studied i . ... 

The literature on iV-alkyl-2,3, or 4-vinylpyridinium salts contains many accounts of spontaneous polymerization to the 1,2-addition polymer during N-alkylation of the vinylpyridine. These attempts to produce other AT-alkyl analogs had always produced the 1,2-addition polymer instead, (Eq. 6.2.2). 

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