Novel homo- and co-poly(p-phenyene ether sulfone benzimidazole/sulfide sulfone benzimidazole)s: synthesis and properties

The homo-and co-poly(p-phenyene ether sulfone benzimidazole/sulfide sulfone benzimidazole)s (PESI/PPSSI) had been prepared by solution polycondensation of the mixtures of 4,4'-dicarboxydiphenyl ether (DCDPE) and 4,4'-dicarboxydiphenyl sulfide (DCDPS) with 3,3',4,4'-tetraanmino diphenyl sulfone (TADS) in polyphosphoric acid (PPA). The FT-IR, H-1-NMR, DSC, TGA, XRD were used to characterize chemical structure and thermal stabilities of the resultant homo-and co-polymers. The inherent viscosities of the resultant polymers were in the range of 0.621-0.982 dl/g at the polymer concentration of 0.5 %. They were found to have excellent thermal properties with glass transition temperatures (T-g) of 386-393 degrees C, 5 % weight-loss temperature (T-5%) of 512-525 degrees C. These polymers showed amorphous nature as charactered by XRD. Most importantly, the resultant polymers possess good solubility that they can be soluble in various aprotic solvents such as N-methyl-2-pyrolidinone (NMP), dimethyl sulfoxide (DMSO) and 1,3-dimethyl-2-imidazolidinone (DMI) and they could be easily formed transparent, tough and flexible membranes by solution casting method. The membranes showed good mechanical properties: the tensile strengths and Young's Modulus were in the range of 68.8-98.6 MPa and 2.1-2.8 GPa, respectively.