Poly(aryl ether ketone ketone)s containing diphenyl-biphthalazin-dione moieties with excellent thermo-mechanical performance and solubility

[Display omitted] •The poly(aryl ether)s with diphenyl-biphthalazin-dione (DBD) moieties are prepared.•DBD units endow polymer with favorable solubility and thermo-mechanical properties.•The solubility and thermo-mechanical properties are compatible by molecule design. High molecular weight poly(aryl ether ketone ketone)s comprising diphenyl-biphthalazin-dione moieties (P-MDs) were prepared through the solution condensation. The structure of polymers was characterized via nuclear magnetic resonance spectra and infrared absorption spectrum. The effects of mixed diphenyl-biphthalazin-dione (mDBD) monomer on performance of polymers were investigated. The mDBD units containing side phenyl groups endow polymer with solubility and controllable contact angle. The resultant polymers perform a fine thermo-stability in both nitrogen and air, presenting an excellent thermal resistance with glass transition temperature in the range of 253–333 °C. Simultaneously, the polymers exhibit a favorable solubility in 1,1,2,2-tetrachloroethane and N-methylpyrrolidone, showing fine film-formation performance. Polymers possess excellent mechanic performance with the tensile strength up to 84 MPa, the Young’s modulus above 1.5 GPa and the retention of storage modulus at 250 °C as high as 70%. Additionally, the contact angle of water-drops with polymer films is within the range of 73.5°–89.1°.