A study of pyridinium-type functional polymers. I. Preparation and characterization of soluble pyridinium-type functional polymers

Copolymerization of 4-vinylpyridine (4VP) with styrene (St) was performed in ethanol using 2,2′-azobisisobutyronitrile (AIBN) as an initiator, and then a random copolymer P(4VP–St) was obtained. A soluble pyridinium-type polymer containing N-benzyl-4-vinylpyridinium bromide [Q-P(4VP–St)], was prepared by quaternization of P(4VP–St) with benzyl bromide (BzBr). The structures of P(4VP–St) and its quaternized product Q-P(4VP–St) were identified by FTIR. The 4VP content in P(4VP–St) and the pyridinium group content (Cq) in Q-P(4VP–St) were determined by nonaqueous titration and argentometry, respectively. The molecular weight of p(4VP–St) was characterized by intrinsic viscosity. In addition, the charge density σ of the soluble pyridinium-type polymers was measured by colloid titration, and the mathematical relation between σ and Cq was established as follows: σ = −0.090 + 0.942 Cq. A preliminary investigation was made into the viscosity behavior and electroconductivity of the Q-P(4VP–St)/polar solvent system. © 1996 John Wiley & Sons, Inc.