Unusual instability effects observed in ionic and non‐ionic water soluble polymers

The solution instability of anionic, cationic and non‐ionic water soluble polymers was observed and examined. This instability can be easily observed by measuring the change in the solution viscosity. A viscosity increase with storage time was observed in the case of aqueous polyvinylalcohol solutions. A viscosity decrease with storage time was observed in the case of aqueous polyacrylamide solutions and derivates of polyacrylamide, also in the case of aqueous solutions of polystyrene sulfonate, starch‐acrylamide graft copolymers, amylose and poly(L‐glutamic) acid. This unusual solution instability was observed when the solutions were stored in the dark, at room temperature, and without mechanical influence. This instability effect is of scientific (molecular origin) and of technical (application) interest. The intention of this paper is to present an overall view of polymers which show this unusual instability effect, to report on the experiments done so far and to discuss possible reasons for this.