Preparation and Characterization of Carbon Membranes Derived from Poly(phthalazinone ether sulfone) for Gas Separation

Abstract

A new polymeric precursor, poly(phthalazinone ether sulfone) (PPES), was used as precursor to prepare carbon membranes via stabilization and pyrolysis. The thermal stability of PPES was determined by thermogravimetry. The evolution of functional groups of membranes was monitored by ATR-FTIR during the formation process of carbon membranes. The carbon structure of the resultant carbon membranes was analyzed by X-ray diffraction technology. The gas permeation property of carbon membranes was tested by pure gases, H 2 , CO 2 , O 2 , and N 2 . The results show that PPES is a highly thermally stable polymer with the char yield of 38.2 wt % at 700°C in nitrogen. The functional groups of PPES gradually disappeared by forming a graphite-like structure in the membrane matrix during pyrolysis. At the test condition of 0.1 MPa and 30°C, the gas permeabilities of H 2 , CO 2 , O 2 , and N 2 for carbon membranes prepared at the stabilization and pyrolytic temperature of 440 and 650°C are 610.13, 439.90, 146.98, and 26.95 barrer (1 barrer ) 10 -10 cm 3 (STP) cm/(cm 2 s cmHg) ) 3.35 × 10 -16 mol m/(m 2 s Pa)), together with the selectivities of gas pairs H 2 /N 2 , CO 2 /N 2 , and O 2 /N 2 of 22.6, 16.3, and 5.5, respectively.

Sintered metal fibers@carbon molecular sieve membrane (SMFs@CMSM) composites for the adsorptive removal of low concentration isopropanol

“…2, the reection bands can be assigned as follows: the -OH bond (3600-3700 cm À1 ), -C]Cdouble bond in aromatic rings (1610 cm À1 ), aromatic C-H (1511 cm À1 ), aliphatic C-H (1459 cm À1 ), the O-H in-plane deformation (1383 cm À1 ), the conjunct contribution of the existence of C-O-C or ]C-O-C groups (1298 and 1090 cm À1 ) structure in RF resin and F127, and the ring CH wagging by two adjacent hydrogen in 1,4-substituted benzene (843 cm À1 ). [26][27][28] For the carbon molecular sieve particle spectrum, most the bands in the spectrum disappeared except for aromatic structure. It can be inferred that nonaromatic atoms gradually decompose from the matrix in the form of H 2 , CO, and CO 2 , etc.…”

“…In the meantime, the residual structure would be combined and reorganized, leading to the formation of more condensed aromatic structure such as carbon sheet, turbostratic carbon. 27 4.1.2. N 2 adsorption/desorption isotherm.…”

CO2 Selective Separation Membranes

“…In addition to preparation and carbonization processes, the use of different precursors affects the gas separation properties of resulting carbon membranes, due to the different thermal degradation mechanisms of polymeric precursors and the microstructures of derived carbon membranes [151] . As an ideal precursor candidate, no defects or pinholes should be formed on the resulting carbon membrane surface after its pyrolysis [75] .…”

“…Poly(phthalazinone ether sulfone) (PPES) is a special member of PPESK polymers, which possess large sulfone and rigid phthalazinone units [151] . For the carbon membranes prepared by pyrolyzing PPES at 650 °C, the CO 2 and N 2 gas permeabilities were 439.90 and 26.95 Barrer, respectively, accompanied with the CO 2 /N 2 selectivity of 16.3.…”

“…For the carbon membranes prepared by pyrolyzing PPES at 650 °C, the CO 2 and N 2 gas permeabilities were 439.90 and 26.95 Barrer, respectively, accompanied with the CO 2 /N 2 selectivity of 16.3. In particular, PPES is the cheapest in the group of PPESK polymers [151] ; thereby it is one of the promising low-cost precursors for the fabrication of carbon membranes.…”