Abstract: There is disclosed novel block copolymers formed of acrylonitrile sequences and sequences containing at least about 50 mole percent of acrylamide units and at most about 50 mole percent organo-substituted amide units and formed by reacting a block copolymer having acrylonitrile sequences and sequences of glutarimide units with a low molecular weight compound having a functional group selected from the group consisting of primary amino and secondary amino group. The reaction is effected at a pH of about 7.5 and higher, preferably in the presence of a solvent and/or swelling agent.

Abstract: There is disclosed block copolymers having acrylonitrile sequences and sequences of glutarimide units of a molecular weight of form about 10,000 to about 2,000,000 where the acrylonitrile sequences and sequences including glutarimide units are of a molecular weight of at least about 400 with the number of sequences being at least about 2 and preferably 5 and higher.