Investigation and fine-tuning of POD membranes by copolymerizing with diglycolic acid

A series of poly (2,5-diphenyl-1,3,4-oxadiazole) (POD) polymers, modified by copolymerization with diglycolic acid in PPA, have been prepared and characterized. The poly (2,5-diphenyl-1,3,4-oxadiazole) and its derivatives were then allowed to form membranes in phosphoric acid solution by phase inversion method. The polymer structures were determined by FTIR, and thermal stability were performed by using TGA. The crystallinity and orientation of polymer were determined by XRD. The morphology of both cross-section and surface of the membranes were further analyzed by SEM. Additionally, data of transmittance and fluorescence of the membranes were collected, as well as oxidation resistance and water absorption of the membranes were tested. The series of PODX membranes obtained in this work exhibited good mechanical properties (up to 48 MPa), chemically inert and thermally stable, and are a class of membrane materials that could be potentially used under harsh conditions. PODX membrane preparation process flow chart. [Display omitted] •Self-polymerization of hydrazides in synthesis, convinient in modification of PODx efficiently.•High quality of POD membrane processing method, easy to tune properties.•Series of PODx membranes being made, chemically inert and thermally stable, exhibiting good mechanical properties.