Reversible binding of sulfur dioxide by polymer‐bound 1,3‐diene acceptor systems

In connection with the removal of sulfur dioxide from waste and flue gases the use of polymer‐bound 1,3‐diene systems has been investigated. Using divinylbenzene/styrene copolymers as the solid support, a number of immobilized 1,3‐dienes were prepared; these were able to bind sulfur dioxide by the formation of the corresponding sulfolene systems. Heating of the latter resulted in liberation of sulfur dioxide with the concomitant recovery of the original 1,3‐diene system. In most cases, upon repeated use of the polymer‐bound 1,3‐dienes, a decrease of the sulfur dioxide binding capacity was observed. Probably, inter‐chain reactions of the diene groups are responsible for this phenomenon.