Thermal analysis and its application in evaluation of fluorinated polyimide membranes for gas separation

Gas Separation Performance of Carbon Molecular Sieve Membranes Based on 6FDA‐mPDA/DABA (3:2) Polyimide

“…[12,35] Therefore, the TGA results in Figure 1 a indicate that the 6FDA-mPDA/DABA (3:2) membrane thermally treated at 370 8C was thermally cross-linked. This sample annealed at higher temperature has only one major weight loss that is caused by degradation of the polymer backbone.…”

“…In our previous research on studying crosslinking of DABAbased polymers, we found that neither the small weight loss in the TGA curve nor the small peak in the derivative weight curve (owing to decarboxylation) was observed in thermally cross-linked membranes. [12,35] Therefore, the TGA results in Figure 1 a indicate that the 6FDA-mPDA/DABA (3:2) membrane thermally treated at 370 8C was thermally cross-linked. This was also confirmed by solubility tests.…”

Carbon molecular sieve membrane structure–property relationships for four novel 6FDA based polyimide precursors

“…The inhibited chain packing introduced by the bulky 6F group provides high free volume and promotes increased solubility to enable facile processing and high permeability in the precursor polymers and resultant CMS materials[27]. Extensive earlier work on 6FDA-DAM, 6FDA:BPDA/DAM, and 6FDA/DAM:DABA CMS films[12,[28][29][30][31] showed DAM to be useful in forming high-performance CMS films; however DETDA, resulting from replacement of two methyl groups in DAM by two ethyl groups, has not been studied previously ODA unit with the packing disruptive 1-5ND unit, seemed like a useful strategy to potentially provide both high selectivity and high permeability.The synthesis of all polyimides involves polycondensation between relevant dianhydrides and diamines in two steps, asFigure 2illustrates for the 6FDA/DETDA:DABA(3:2) case. In the…”

Exploiting pyrolysis protocols on BTDA‐TDI/MDI (P84) polyimide/nanocrystalline cellulose carbon membrane for gas separations

“…Approximately 4% of the weight loss of pure PI at 100 °C was due to the evaporation of moisture in the powdered sample. The stabilization temperature was kept below the degradation temperature ( T d ), which is defined as the temperature corresponding to 5–10% weight of precursor remaining . Previously, the glass‐transition temperature of PI‐copolyimide was reported at 315 °C.…”