Epoxy functionalized poly(aryl ether sulfones) copolymers

A process for preparing copolymer (P1) comprising at least partially epoxidizing a copolymer (P0) comprising:

• recurring units (RP0) of formula (M):
• recurring units (R*P0) of formula (P):
• optionally at least 50 μeq of hydroxyl end groups, amine end groups, acid end groups or epoxy end groups,
• wherein
• each R1 is independently selected from the group consisting of a halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali or alkaline earth metal sulfonate, alkyl sulfonate, alkali or alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium;
• each i is independently selected from 0 to 4;
• GP is selected from the group consisting of at least one of the following formulas:
• each k is independently selected from 0 to 4,
• T and Q are independently selected from the group consisting of a bond, —CH2—, —O—;
• —SO2—;
• —S—;
• —C(O)—;
• —C(CH3)2—;
• —C(CF3)2—;
• —C(═CCl2)—;
• —C(CH3)(CH2CH2COOH)—;
• —N═N—;
• —RaC═CRb—, where each Ra and Rb, independently of one another, is a hydrogen, a C1-C12-alkyl, C1-C12-alkoxy, or C6-C18-aryl group;
• —(CH2)m— and —(CF2)m— with m being an integer from 1 to 6;
• an aliphatic divalent group, linear or branched, of up to 6 carbon atoms;
• and combinations thereof.