Thermal stability of modified telechelic polystyrenes

The thermal stability of telechelic polystyrenes bearing quaternary ammonium iodide or ammonium sulfonate end groups is presented. It appears that the ammonium iodide functions are stable below 200°C. Above that temperature, the polystyrene irreversibly looses its functional end groups. The weight loss then observed leads to the conclusion that a Hofmann‐type degradation mechanism is likely to take place. In contrast, the ammonium sulfonate‐terminated polystyrene begins to degrade at 180°C and leads to a polymer which is no longer end‐capped with sulfonic acid or sulfonate groups. This behavior is of importance, especially for the study of multiblock ionic copolymers which are prepared by blending two telechelic polymers, one of them bearing sulfonic acid end groups and the other one tertiary amine functional groups. © 1993 John Wiley & Sons, Inc. Copyright © 1993 John Wiley & Sons, Inc.