4 4 diaminodiphenylmethane

Matrimid^® 5218 (Matrimid) was purchased from Alfa Aesar (Haverhill, MA, USA). p-Phenylenediamine (p-PDA, >98%) and 4,4′-diaminodiphenylmethane (MDA, >97%) were purchased from Sigma Aldrich (St. Louis, MO, USA). m-Tolidine (>98%), bis(trifluoromethyl)benzidine (TFMB, >98%), and 2,2-bis(4-aminophenyl)hexafluoropropane (6FpDA, >98%) were purchased from Tokyo Chemical Industry (TCI, Tokyo, Japan). Methanol (MeOH, 99.5%) and N-methyl-2-pyrrolidone (NMP, 99.5%) were purchased from Daejung Chemicals and Metals (Siheung-si, Gyeonggi-do, Korea). All gases for permeation tests were purchased from AirKorea (Yeoju-si, Gyeonggi-do, Korea). Figure 1 illustrates the chemical structures and assigned names of the polyimide (MAT), non-fluorinated diamines (DA), and fluorinated diamines (FDA) used in this study.

Pyromellitic dianhydride, 4,4′-diaminodiphenyl ether, m-phenylenediamine, 3,4′-diaminodiphenyl ether, p-phenylenediamine, 5,5′-((propane-2,2-diylbis(4,1-phenylene))bis(oxy))bis(isobenzofuran-1,3-dione), and 4,4′-diaminodiphenylmethane were purchased from Sigma-Aldrich. α,α′-Bis(4-aminophenyl)−1,4-diisopropylbenzene, 4-bis(4-aminophenoxy)-benzene, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride and 4,4′-oxydiphthalic anhydride were purchased from TCI. 2-Methyl-m-phenylenediamine and 1,2,4,5-cyclohexanetetracarboxylic dianhydride were provided by Anhui Zesheng Technology Co., Ltd.

Cellulose nanofibers (CNFs, 2.0 wt%) were procured from Moorim Paper MFG Co., Ltd., South Korea. CNF suspension of 1 mmol/g with an average width of less than 100 nm and length of up to several micrometers. Fig. S1 (Supporting Information) represents the CNFs' TEM image and the length distribution. The width and length were measured from the TEM image. Vanillin (98 %), epichlorohydrin (ECH, 99 %), tetrabutylammonium bromide (TBAB, ≥99 %), 4, 4´-diaminodiphenyl methane (DDM, ≥97 %) were received from Sigma Aldrich. Anhydrous sodium sulfate (99 %) was procured from Yakuri Pure Chemicals Co., Ltd., Japan. Dichloromethane (DCM, >99.9 %) was obtained from Samchun, South Korea. Acetone (99.5 %), sodium hydroxide (97 %), and ethanol (99.5 %) were obtained from Daejung Chemical and Metals Co., Ltd., South Korea.