Cation exchange resin from phosphorylated N‐vinylcarbazole formaldehyde copolymer

Abstract

AbstractCrosslinked copolymers of N‐vinylcarbazole and poly N‐vinylcarbazole) and formaldehyde have been phosphorylated using PCl3 and anhydrous AlCl3 under different conditions. The cation exchange resins, thus obtained, have been characterized by elemental analyses, evaluation of total ion‐exchange capacities and salt‐splitting capacities, pH metric titration behavior, and IR analysis. The phosphorylated resin exhibites significantly better thermal stability than the corresponding sulfonated N‐vinylcarbazole–formaldehyde cation exchange resin or the unmodified N‐vinylcarbazole–formaldeyde copolymer, as well as the phosphorylated poly(N‐vinylcarbazole). The phosphorylated resins also behave as polymeric dyes with pH dependent color change. Possible explanations for color change and ion‐exchange capacity differences have been attempted on the basis of the structural characteristics of the resins.