Gas transport property of the binaphthyl-based polyimide membranes. (21st November 2019)

• Record Type: Journal Article
• Authors: Deng, Guoxiong; Wang, Yilei; Zong, Xueping; Yuan, Xiaoxu; Luo, Jiangzhou; Wang, Xuezhen; Xue, Song
• Is Part Of: Polymer. Volume 183(2019)
• Publication Date: 2019-11-21
• Subjects: Binaphthyl diamine -- Aromatic polyimide -- Gas separation; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2019.121854
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: There is constant need for improving the performance of gas separation membranes for making the membrane technologies viable for industrial applications. In this work, we introduce an array of novel polyimide (PI) membranes containing binaphthyl moieties for gas separations. Using two different methods, chemical or azeotropic imidization, we have synthesized PIs with hydroxyl (OH) group or acetate (OAc) groups based on binaphthyl diamine and three different di-phthalic anhydride monomers (6FDA, BTDA, and ODPA). Permeabilities of H2, CO2, O2, N2 and CH4 were evaluated on six membranes under 0.2 MPa. The contorted binaphthyl PIs are able to sieve small gas molecules in general. Bulky OAc side groups in PI increase free volume via preventing the polymer chains from packing and cause higher gas permeability. The new binaphthyl-based polyimide architecture is developed for a possible application in gas separation. Graphical abstract: Image 1 Highlights: A contorted binaphthyl diamine derived from 1, 1'-binaphthol with C2 -symmetry were synthesized. Two naphthyl rings can construct contorted moieties in the polyimide and provide proper free volume in the membranes. Polymer chain rigidity and the prohibition of its rotation via side group are crucial to attain high permeability. Through XS1, the CO2 in a binary mixed-gas of CO2 /N2 was successfully enriched from 15% (v/v) to 82% (v/v).