A Poly(aryl Ether Sulfone) Containing Bis-phthalazinone with High Thermal Resistance

A series of poly(aryl ether sulfone)s including bis-phthalazinone moieties (PBPES-Ps) that displayed improved heat resistance were obtained through condensation polymerization. The structures of the PBPES-Ps were investigated by FT-IR, 1H NMR, and XRD. The heat resistance of the PBPES-Ps can be regulated according to the monomer contents in the polymerization. The glass transition temperature (Tg) of PBPES-Ps was 280–349 °C and the 5% mass loss temperature was up to 514 °C. The PBPES-Ps had high mechanical and thermo-mechanical characteristics, i.e., the storage modulus and the tensile strength of PBPES-Ps were as high as 1.81 GPa and 95.3 MPa, respectively. Furthermore, the storage modulus retention reached 76.5% at 220 °C. With the introduction of the 4,4′-di(4′-1(2H)-phthalazinone)-1,1′-biphenyl (BPBN), both the dielectric loss (Df) and dielectric constant (Dk) of PBPES-Ps decreased, and the lowest values of Df and Dk were 0.0061 and 2.95 at 1 GHz, respectively. The PBPES-Ps' hydrophobicity declined with the increasing BPBN content. In addition, the PBPES-Ps were soluble in conventional solvents like N-methyl-2-pyrrolidinone as well as 1,1,2,2-tetrachloroethane.