Precursors of hydrophilic polymers, 7. Potentiometric properties and structure of copolymers of 2‐dimethylaminoethyl methacrylate

Abstract

Abstract The study concerns the potentiometric behaviour of statistical copolymers of 2‐dimethylaminoethyl methacrylate with 2‐hydroxyethyl methacrylate, acrylamide, methacrylamide, 2‐methacryloyloxyethyltrimethylammonium methylsulfate, and of copolymers arising by the partial quaternization of poly(2‐dimethylaminoethyl methacrylate) with methyl iodide in various water‐ethanolic solutions. The potentiometric properties of poly(4‐dimethylaminobutyl methacrylate) and poly(6‐dimethylaminohexyl methacrylate) are also reported. The course of modified titration curves and the differences between p K 0 values of copolymers and p K values of low‐molecular weight model compounds are discussed. Side chains of copolymers of 2‐dimethylaminoethyl methacrylate have a cyclic conformation (similarly to the homopolymer); the carbonyl and amine group interact with each other. Copolymers formed by the partial quaternization of poly(2‐dimethylaminoethyl methacrylate) with methyl iodide in a water‐ethanolic medium (Menshutkin's reaction) have a block structure, which suggests a zip mechanism of the quaternization reaction.