Optical, thermal and gas separation properties of acetate-containing copoly(ether-imide)s based on 6FDA and fluorenyl diamines

Abstract

The diamine, 9,9-bis[4-(4-amino-3-hydroxylphenoxy)phenyl]fluorene (BAHPPF) was synthesized by the modified two-step method. Then, a series of acetate-containing copoly(ether-imide)s were prepared by the copolymerization of BAHPPF, 9,9-bis(4-aminophenyl)fluorene (BAF) and 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) followed by chemical imidization. The structures and properties of the BAHPPF and copoly(ether-imide)s were characterized by nuclear magnetic resonance spectrometer (NMR), Fourier transform infrared spectrometer (FTIR), X-ray diffractometer (XRD), differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), ultraviolet-visible spectrophotometer (UV-VIS), and tensile testing. Single gas permeation performances of these copoly(ether-imide)s were also studied for five representative gases of interest including H2, O2, N2, CO2, and CH4. The experimental results showed that the copoly(ether-imide)s showed excellent optical properties with high light transmittance above 80.2% at 450 nm. The glass transition temperature of these copolymers were higher than 333°C. Their tensile strength and Young’s module also increased, and the elongation decreased with the decrease of BAHPPF. High gas permeabilities of copoly(ether-imide)s were obtained, and the ideal selectivity of CO2/CH4 was improved due to the introduction of acetate group and flexible ether linkage. These copoly(ether-imide)s could be applied to the field of optics and gas separation.

Synthesis and gas permeation properties of thermally rearranged poly(ether-benzoxazole)s with low rearrangement temperatures

“…The ether-containing bis(o-aminophenol) monomer, 9,9-bis[4-(4-amino-3-hydroxyl phenoxy)phenyl]uorene (bis-AHPPF) was synthesized in two steps, according to our previously reported method, from 9,9-bis(4-hydroxylphenyl)uorene and 5-uoro-2nitrophenol by nucleophilic aromatic substitution in the presence of potassium carbonate (K 2 CO 3 ) and DMF as solvent, followed by catalytic reduction with hydrazine hydrate and Pd/C as catalyst. 45…”

“…For the details of the test procedure, please refer to our previous report. 45 In the study, the feed pressure and testing temperature were maintained at 0.01 or 0.1 MPa and 30 C, respectively. The gas permeabilities were determined from the eqn (3).…”

“…FTIR and 1 H NMR results identied the chemical structures of the intermediate dinitro compound and the nal hydroxyl diamine monomer, which were reported in our previous literature. 45…”

Enhanced CO2 separation properties by incorporating acid-functionalized graphene oxide into polyimide membrane

“…(a) CO 2 /CH 4 selectivity and (b) CO 2 /N 2 selectivity of membranes.ratio GO-MDI-EDTA leads to a highly tortuous gas diffusion path in the membrane; thus, the larger molecules will sustain a bigger transfer resistance than smaller ones. The kinetic diameters of CH 4 (0.38 nm) and N 2 (0.36 nm) were larger than that of CO 2 (0.33 nm) 45. Thus, the CO 2 /CH 4 and CO 2 /N 2 selectivities will be increased.…”

New fluorinated polyimides based on 1,2-bis(4-aminophenyl)-4,5-bis(4-trifluoromethylphenyl)-1H-imidazole

“…Generally, it is noted that introduction of the fluorine groups like trifluoromethyl group into the backbone or side chain of the PIs has been considered as an effective approach, 15 which could not only improve their solubility and optical transparency together with a lowered dielectric constant and color, but also provide other merits such as good thermal and thermo-oxidative stability and low moisture absorption. [16][17][18][19][20][21] On the other hand, introducing unsymmetrical structure into the PI main chain could lead to the improvement in solubility and melt processability and other desirable properties. [22][23][24] Moreover, the formation of unsymmetrical unit through the incorporation of rigid heteroaromatic structure into the PI backbone would impart it certain properties expected.…”