Crosslinking structures of POD membranes copolymerized with nitrilotriacetic acid and their properties. (1st February 2022)

• Record Type: Journal Article
• Authors: Xie, Wenlian; Li, Lihong; Wang, Xiaogang; Yuan, Limin; Zhu, Zhiqiang
• Is Part Of: Polymer. Volume 240(2022)
• Publication Date: 2022-02-01
• Subjects: Nitrilotriacetic acid -- Aromatic polyoxadiazole (POD) -- Polymer membranes -- Network structure -- Chemically modified POD; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2021.124484
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: A series of N-PODX polymers with network structure were prepared by condensation reactions of terephthalic dihydrazide (TPH) and different amounts of nitrilotriacetic acid (NTA) in polyphosphoric acid (PPA), the corresponding membranes were formed by phase inversion method. The modified polymers form network motifs with different cross-linking densities internally, which has a great influence on the membrane properties. The membrane structures were characterized by IR, and thermal stability were measured by TGA and DSC. Fluorescence and transmission properties of samples were tested with spectrophotometer, and their crystallization behavior was observed by XRD. The surface and section morphology of membranes were evaluated by SEM. Additionally, performance of their oxidation resistance and water absorption were explored. Overall, not only have N-PODX membranes exhibited hydrophobic property, highly thermal and chemical stability, but they also showed greatly mechanical properties (up to a maximum of 66.19 MPa) and are kinds of membrane materials with potential applications in market. Graphical abstract: Image 1 Highlights: Nitrilotriacetic acid modified N-PODX polymers and membranes, with network structure, are synthesized and prepared. Crosslinking density of network structure of N-PODX is adjusted rationally and efficiently with acid content. The family of N-PODX membranes shows high thermal stability, chemically inert and good mechanical properties. The best comprehensive properties are observed on N-POD6 membrane, the stress is up to a maximum of 66.19 MPa. Molecular structural effect on properties of N-PODX membranes are revealed.