Collect. Czech. Chem. Commun. 1995, 60, 1728-1732

Electrically Induced Structural Changes in Quaternized Methyl Methacrylate-N-[2-methyl-5-(dimethylamino)phenyl]maleimide Copolymer Membranes

Vlastimil Kůdela and Jan Lokaj

Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6, Czech Republic


Homogeneous membranes were prepared by casting chloroform solutions of methyl methacrylate-N-[2-methyl-5-(dimethylamino)phenyl]maleimide copolymers containing 2.3-8.7 mole % of the imide. After quaternization with methyl iodide, diffusive permeabilities and electric resistances (both with alternating and direct current) of the membranes were determined. During the passage of electric current a substantial decrease (2-10 fold) in the membrane resistance was observed; the lower the imide content was, the greater was the effect. The decrease suggests structural changes in the membranes due to electrohydrodynamic convection of unstable polymer chains caused by electric force. Significant correlations between the imide content and the resistance, both before and after the treatment with electric current, were found. According to oriented concentration potentials, the internal symmetry of the membranes was also affected by electric current.