Polymeric composite membrane fabricated by 2-aminoterephthalic acid chemically cross-linked polyvinylamine for CO2 separation under high temperature

•PVAm membrane chemically cross-linked by cyclic small molecular amine is prepared.•Combined effect of chemical cross-link and cyclic amine on performance is achieved.•The membrane shows superior CO2 separation performance under high temperature.

Improvement of the performance of CO2 separation membrane under high temperature is of great importance in industrial applications. In this work, 2-aminoterephthalic acid (AA) was used to chemically cross-link polyvinylamine (PVAm) to fabricate PVAm-AA aqueous solution. PVAm-AA/polysulfone(PSf) composite membrane was then prepared by coating PVAm-AA aqueous solution on PSf support membrane. Through the chemical cross-linking by AA, the polymer chain mobility was restrained, resulting in the enhancement of thermal stability. The introduction of AA also increased the effective carrier content for CO2 separation. Therefore, CO2 permeance and CO2/gas selectivity of PVAm-AA/PSf membrane under relatively high temperature were greatly improved. For CO2/N2 mixed gas (15/85 by volume), PVAm-AA/PSf membrane showed a CO2 permeance of 661 Gas Permeation Unit (GPU) and CO2/N2 selectivity of 95 at 0.3 MPa and 120 °C. Excellent performance stability was shown during the operation for 250 h at 120 °C. Moreover, PVAm-AA/PSf membrane displayed excellent separation performance and thermal stability for the separation of CO2/CH4 and CO2/H2 mixed gases.