HEAT-TREATMENT, AND ALKALINE-TREATMENT IN DUCED COLORING STRUCTURES IN POLYMETHACRYLONITRILE

Coloration and discoloration of alkali-treated polymethacrylonitrile ( PMAN) solutions and heat-treated PMAN films was studied by electronic absorption spectroscopy. It was found that coloration of the polymer i s caused by the formation of clusters of carboxyl-containing groups or acidic groups with comparable ionicity. The carboxyl-containing and a cidic groups combine into clusters because they are thermodynamically incompatible with the hydrophobic polymer matrix. Discoloration of the solutions exposed to air and the films boiled in water is caused by t he solvation effect of water leading to the dissipation of clusters