Copolymerization of Acrylo- or Methacryloguanamine with Unsaturated Carboxylic Acid and Properties of the Copolymers

Abstract

The homopolymerization of acryloguanamine (2, 4-diamino-6-vinyl-1, 3, 5-triazine) and the copolymerization of this with acrylonitrile in the presence of acid were investigated in dimethyl sulfoxide (DMSO) at 60°C using α, α'-azobisisobutyronitrile as an initiator. The rate of polymerization of acryloguanamine hydrochloride was less than that of free acryloguanamine, and Q and e values of the former were larger than those of the latter. This suggested that the reactivity of polymerization of acryloguanamine could be controlled by the addition of an acid.
When the copolymerization of acrylo- and/or methacryloguanamine (2, 4-diamino-6-isopropeny11, 3, 5-triazine) with acrylic and/or methacrylic acid was carried out under above-mentioned conditions, a highly alternating excellent copolymer was easily obtained, which could be due to hydrogen bonding formed by an interaction between a weak base of amino-1, 3, 5-triazine ring and unsaturated carboxylic acid. Methacrylic acid-methacryloguanamine copolymers containing 31∼75 mol% of triazine rings were soluble in DMSO, readily soluble in either acid or alkaline aqueous media, and insoluble in aqueous solution whose pH showed near neutral values. The titration curves of these copolymers in alkaline solution were similar to that of poly (methacrylic acid). The reduced viscosity increased with dilution in the case of acid or basic solution, but decreased linearly in the case of aqueous sodium chloride solution or DMSO. These results indicated that the copolymers were ampholytes. The isoelectric point of these ampholytes increased, with triazine ring content from pH 4.2 to 6.1 and showed an aggregation effect toward aqueous suspension of kaolin.