The preparation and characterization of the block copolymers of polysulfone were described in this paper. It was clearly of interest to investigate this area to establish structure-property relationships and the potential usefulness of such materials. It was reasoned that block copolymers prepared from such rigid amorphous engineering thermoplastics with a second crystalline segment would lead to vastly improved material performance. Such a system possessing an A-B-A (or A-B) structure in which the B represent a Polysulfone segment(PSF) and A represent crystalline segment e. g. PBT

N6

HQ-PSF etc. The presence of the crystalline segment should result in an overall enhanced solvent and stress crack resistance. The results show

that A-B-A(or A-B)block copolymers can be a compatible agent for polymer-polymer system and solvent-solvent system.