Interfacial polycondensation. IX. Polysulfonamides

Abstract Polysulfonamides may be prepared readily in high molecular weight by interfacial polycondensation. They are formed rapidly at room temperature when a disulfonyl chloride in an organic solvent is emulsified with a diamine in water containing an acid acceptor. The highest polymers have been obtained from aliphatic diamines and aromatic disulfonyl chlorides. Aromatic diamines have given only low molecular weight materials. Reaction conditions for preparing poly(hexamethylene‐1,3‐benzenedisulfonamide) are briefly described. Reactants must be very pure. Dichloromethane and chloroform have been the most useful organic solvents and must be pure and dry. The best concentrations are about 0.1 M . The pH and the ionic strength of the aqueous phase exert a power ful effect on the desired partition of diamines between the two phases and the undesired hydrolysis of the sulfonyl chloride. Thus, sodium carbonate works better than sodium hydroxide as an acid acceptor and, in some cases, bicarbonate has been used to avoid imide formation and consequent branching.