Lu, Yunhua; Zhang, Jianhua; Xiao, Guoyong; Li, Lin; Hou, Mengjie; Hu, Junyi; Wang, Tonghua published the artcile< Synthesis and gas permeation properties of thermally rearranged poly(ether-benzoxazole)s with low rearrangement temperatures>, Recommanded Product: Cyclobuta[1,2-c:3,4-c’]difuran-1,3,4,6(3aH,3bH,6aH,6bH)-tetraone, the main research area is polyetherbenzoxazole synthesis thermal rearrangement gas permeation property.
The diamine monomer, 9,9-bis[4-(4-amino-3-hydroxylphenoxy)phenyl] fluorene (bis-AHPPF) was successfully synthesized according to our modified method. A series of hydroxyl-containing poly(ether-imide)s (HPEIs) were prepared by polycondensation of the bis-AHPPF diamine with six kinds of dianhydrides, including 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), pyromellitic dianhydride (PMDA), 3,3′,4,4′-biphenyl tetracarboxylic diandhydride (BPDA), 3,3′,4,4′-oxydiphthalic anhydride (ODPA), 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and 4,4′-(hexafluoroisopropylidine)diphthalic anhydride (6FDA) followed by thermal imidization. The corresponding thermally rearranged (TR) membranes were obtained by solid state thermal treatment at high temperature under a nitrogen atm. The chem. structure, and phys., thermal and mech. properties of the HPEI precursors were characterized. The effects of heat treatment temperature and dianhydrides on the gas transport properties of the poly(ether-benzoxazole) (PEBO) membranes were also investigated. It was found that these HPEIs showed excellent thermal and mech. properties. All the HPEI precursors underwent thermal conversion in a N2 atmosphere with low rearrangement temperatures The gas permeabilities of the PEBO membranes increased with the increase of thermal treatment temperature When HPEI-6FDA was treated at 450°C for 1 h, the H2, CO2, O2 and N2 permeabilities of the membrane reached 239.6, 196.04, 46.41 and 9.25 Barrers coupled with a O2/N2 selectivity of 5.02 and a CO2/N2 selectivity of 21.19. In six TR-PEBOs, PEBO-6FDA exhibited the lowest rearrangement temperature and largest gas permeabilities. Therefore, thermally rearranged membranes from bis-AHPPF-based HPEIs are expected to be promising materials for gas separation
RSC Advances published new progress about Complex modulus, tan δ. 4415-87-6 belongs to class tetrahydrofurans, and the molecular formula is C8H4O6, Recommanded Product: Cyclobuta[1,2-c:3,4-c’]difuran-1,3,4,6(3aH,3bH,6aH,6bH)-tetraone.
Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem