Sulfuric Acid → Hydrochloric Acid

Participants

Reaction Steps

700 g of N-hydroxymethyl phthalimide, dissolved in 2400 g of dichlorethane, are heated for 5 hours to reflux temperatures with 454 g of acetic acid anhydride. 300 g of a styrene polymer crosslinked with 6 % of divinyl benzene are swollen in this ester solution over a period of 30 minutes at 60° C. 400 g of concentrated sulphuric acid are then added dropwise over a period of 4 hours at reflux temperature. After stirring for 20 hours at the same temperature, the polymer is filtered off under suction and suspended in 2000 ml of 10 % aqueous ammonia solution. The residues of swelling agent are removed from the suspension by azeotropic distillation. The polymer is then heated for 10 hours to 180° C with 40 % sodium hydroxide solution in an autoclave. After the sodium hydroxide has been washed out, 750 ml of a weakly basic anion exchanger are obtained with an acid binding capacity of 3.3 Val/1 for N/10 hydrochloric acid and a nitrogen content of 9.55 % in the dry material.

Provenance & Evidence