A polyarylethersulphone copolymer which is a hydrophilic sulphonated copolymer derived by controllably sulphonating a copolymer having the repeat unit of formula ##STR1## together with the repeat unit B of formula ##STR2## substantially all the units A being sulphonated after sulphonation and substantially all the units B remaining non-sulphonated after sulphonation. The sulphonation is effected using 98% w/w sulphuric acid.

Molding compositions comprise A) from 1 to 98.8% by weight of at least one polyarylene ether sulfone, B) from 1 to 98.8% by weight of at least one thermoplastic polyamide, C) from 0.1 to 60% by weight of at least one filler, D) from 0 to 40% by weight of at least one impact-modifying rubber, E) from 0 to 40% by weight of one or more different additives, and F) from 0.1 to 30% by weight of at least one thermotropic polymer, where the total of the percentages by weight of components A to F is 100%...