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A number of low molecular weight sulfonated aromatic compounds: carboxamides, imides, sulfonamides, as well as sulfonated polymers; aramides and poly(styrene‐p‐sulfonic acid), were tested for their stability on heating in water and dilute acid to temperatures ranging from 130–200 °C. Desulfonation was observed with some compounds. Sulfonamide linkages were found to be stable, while carboxamide linkages and phthalimides were not.

Arylene ether multiblock copolymers of the (AB)n‐type with various degrees of sulfonation have been prepared by a two‐step polycondensation procedure. Multiblock copolymers in high yields and of high molecular weights were obtained. For comparison random copolymers with the same overall composition were synthesized. The theoretical ion‐exchange capacities (IEC) of the materials were ranging from 0.50 mmol/g to 1.25 mmol/g. The water‐uptake of the multiblock copolymers showed a linear dependency from the IEC and was increasing with increasing IEC. No differences were observed between random and block copolymers. Furthermore, the hydrolytic stability of aromatic sulfonic acid groups was investigated in this study. Aromatic sulfonic acids, having additional electron donating groups, especially in ortho‐ or para‐position to the sulfonic acid group are sensitive to hydrolytic desulfonation. On the other hand electron‐withdrawing groups in meta‐position showed a stabilizing effect.

Abstract. Novel oligomeric/polymeric additives with ionic units were synthesized in a one pot procedure in order to enhance the specific surface resistivity of SMC-materials. In contrast to industrially used inorganic salts or carbon materials, such as carbon black or CNT´s, these substances are nearly colorless and matrix compatible and, resulting from that, easy to homogenize with the SMC-matrix. Furthermore, it was found, that additives which can be covalently bonded to the matrix during the molding procedure are preferred compared to physically mixed substances. The effectiveness of chemically bonded substances regarding with the lowering of the specific surface resistivity is higher and selected additives do not change the reactivity and resulting mechanical properties of the molded material.