A series ofpoly（aryl ether sulfone ketone）s containing phthalazinone and biphenyl moieties were synthesized by aromatic nucleophilic displacement polycondensation of 4-（4-hydroxylphenyl）（2H）-phthalazin-l-one （DHPZ）, 4,4＇- dichlorobenzophenone （DCB）, 4,4＇-dichlorodiphenyl sulfone （DCS） and 4,4＇-biphenol （BP） in different molar ratios. The obtained copolymers were characterized by different instrumental techniques （FTIR, TGA, DSC, WAXD, etc.）. The inherent viscosities of these polymers were in the range of 0.43-0.56 dL g^-1. They were amorphous and had good solubility in polar aprotic organic solvents. The copolymers exhibited high glass transition temperatures （TgS） between 225℃ and 256℃and excellent thermal stability up to 517-526℃ （thermal decomposition temperatures for 5% weight loss, Td, 5%） in nitrogen. The tensile strength and elongation at break of the polymers ranged from 63 MPa to 71 MPa and from 18% to 21%, respectively. The processability of the material was effectively improved by the introduction of biphenyl group into polymer backbone.
