Synthesis of almost fully quarternized poly(4-vinylpyridine)s by polymer reaction and aggregation property with sodium dodecyl sulfate

Quarternized poly(4-vinyl pyridine)s have been prepared by the reaction of poly(4-vinyl pyridine)s (Mw = 50 kg/mol and 200 kg/mol) and alkylating agents varying the carbon numbers of the alkyl groups (m): dimethyl sulfate (m=1) as well as bromoalkane (m=5, 8, 12, 16, and 22) was used as an alkylating agent. The degree of alkylation was determined by using an elemental analysis and NMR spectroscopy. As a result, polyelectrolytes were obtained by the almost full alkylation of poly (4-vinyl pyridine)s. The critical aggregation concentration (CAC) was determined by measuring the change of turbidity occurred by addition of sodium dodecyl sulfate (SDS) into aqueous solution of quarternized poly(4-vinyl pyridine) s. and the dependence of molecular weight of polymer, the length of N-alkyl group and concentration of NaCl upon CAC was investigated. As a result, as the molecular weight or the length of alkyl group was increased, less amount of SDS could induce the aggregation.