Fabrication and characterization of modified POD membranes with ultra-high tensile strength through hydrogen bonding functioning and copolymerization

A series of modified aromatic oxadiazole polymers were synthesized via condensation reactions of terephthalic dihydrazide (TPH) and varying amounts of Trimesic acid (H3BTC) in polyphosphoric acid (PPA). Pentaerythritol was introduced to construct intermolecular hydrogen bonds among polymeric chains, resulting in a three-dimensional network structure, and correlations between H-bonds and mechanic properties are discussed. Structures and mechanic properties of the polymers were characterized and analyzed. By investigation of molecular structure and membrane formation process of chemically modified and hydrogen bond-regulated polymer membranes, it was found that the modified polymer membranes retain the unique thermal stability, chemical stability, and good hydrophobicity of the POD rigid polymer. Additionally, hydrogen bonds not only significantly improve the overall quality of the membrane, but also play an important role in enhancing the mechanical properties of the membrane, as demonstrated in the highest observed of up to a maximum of 167.19 MPa. Furthermore, impact of H3BCT modification on light absorption and fluorescence performance of T-PODx is also analyzed and discussed in this paper.