Semi-Biobased Polyamide Membranes Derived from 2,5-Furandicarboxylic Acid for Gas Separation

The synthesis of biobased plastics is highly attractive from the viewpoint of oil depletion and the transition toward sustainable development. In this study, semi-bio-poly- and copolyamides were obtained from biobased 2,5-furandicarboxylic acid (FDCA) with different diamines containing tetracyclo, −CH3, and −C(CF3)2– groups. Four processable aromatic semi-bio-polyamides provided flexible transparent membranes with tunable gas separations, plasticization resistance in the tested range (2–10 bar), and good thermal and mechanical properties. The co-PMBD copolyamide containing FDCA and methylenebis(2,6-dimethylaniline) (MBD) displayed the highest gas permeability with good selectivity for CO2 and H2 (PCO2 = 26.9 and PH2 = 69.8 with H2/CH4 = 61.2 and CO2/CH4 = 23.6) in comparison with its homologues. All FDCA based membranes obtained exhibited higher permeability with a similar H2/CH4 and CO2/CH4 selectivity compared to commercial Matrimid and cellulose acetate membranes. Moreover, after 30 days of enzymatic degradation, membrane surfaces presented noticeable hollow cavities and uneven surfaces.