CHAIN CONFORMATION OF BLOCK COPOLYMERS IN DILUTE-SOLUTIONS MEASURED BY SMALL-ANGLE NEUTRON-SCATTERING

Abstract

Chain dimensions of the polystyrene-d8 parts of a styrene-d8-2-vinylpyridine block copolymer (DP-33) and a styrene-d8-styrene-h8 block copolymer (DH-44), both with 50 : 50 compositions, were measured in dilute solutions of pyridine (a common good solvent) benzene (a selective solvent) and methyl ethyl ketone (a poor solvent) by small-angle neutron scattering. The conformation of one block chain within a diblock copolymer is not affected by the existence of another block chain, regardless of the solvent power at least when the composition of the diblock copolymer is 50 : 50, and the molecular weight is not high.