The use of oligomers with acid halide end groups in the synthesis of block copolymers

A NEW method of synthesis of block copolymers of aromatic polyamides with polyhetero-arylenes, based on an irreversible low-temperature polycondensation in solution of oligomers with different functional end groups, was described in an earlier communication [l]. Oligomers with anhydride or aminoend groups were used for this purpose. The use of oligo-acid dichlorides in a block copolymer production was found to be made difficult by the rapid reactivity loss in amide solvents, yet the rejection of such oligomers greatly reduced the synthesis possibilities of block copolymers by the above method.