Polyimide(PI) is a type of important membrane material. A soluble polymer was synthesized from 4,4′-(hexafluoroisopropylidene) diphthalic anhydride(6FDA) and 2,2-bis[4-(4-aminophenoxy) phenyl] hexafluoroprop...Polyimide(PI) is a type of important membrane material. A soluble polymer was synthesized from 4,4′-(hexafluoroisopropylidene) diphthalic anhydride(6FDA) and 2,2-bis[4-(4-aminophenoxy) phenyl] hexafluoropropane(BDAF) by the two-step polymerization method. The polymer was proved to be polyimide 6FDA-BDAF by the Fourier transform infrared(FT-IR), the 1H-NMR and ^(19)F-NMR spectra. An asymmetric membrane was prepared with the synthesized polyimide 6FDA-BDAF, it was porous in the 50 μm height bulk and dense in a 3–5 μm height surface. The membrane was used to separate n-heptane/thiophene mixtures by pervaporation with sulfur(S) contents from 50 to 900 μg g^(–1). The total flux was enlarged from 7.96 to 37.61 kg m^(–2) h^(–1) with temperature increasing from 50 to 90°C. The membrane's enrichments factor for thiophene were about 3.13 and dependent on the experimental conditions. The experimental results demonstrated that polyimide 6FDA-BDAF would be a potential membrane material for desulfurization and controlled release of the S-containing fertilizer.展开更多
基金support from the Key Technology R&D Program of China(2011BAD11B05)the National Nonprofit Institute Research Grant of Chinese Academy of Agricultural Sciences(2011-28,2013-17)+3 种基金supported by the National Basic Research Program of China(973 Program,2003CB615701)the National Natural Science Foundation of China(20576059,20676067,31572204)the China Petroleum&Chemical Corporation(SINOPEC Foundation,X505002)the China National Petroleum Corporation(CNPC)InnovationFoundation(05051143)
文摘Polyimide(PI) is a type of important membrane material. A soluble polymer was synthesized from 4,4′-(hexafluoroisopropylidene) diphthalic anhydride(6FDA) and 2,2-bis[4-(4-aminophenoxy) phenyl] hexafluoropropane(BDAF) by the two-step polymerization method. The polymer was proved to be polyimide 6FDA-BDAF by the Fourier transform infrared(FT-IR), the 1H-NMR and ^(19)F-NMR spectra. An asymmetric membrane was prepared with the synthesized polyimide 6FDA-BDAF, it was porous in the 50 μm height bulk and dense in a 3–5 μm height surface. The membrane was used to separate n-heptane/thiophene mixtures by pervaporation with sulfur(S) contents from 50 to 900 μg g^(–1). The total flux was enlarged from 7.96 to 37.61 kg m^(–2) h^(–1) with temperature increasing from 50 to 90°C. The membrane's enrichments factor for thiophene were about 3.13 and dependent on the experimental conditions. The experimental results demonstrated that polyimide 6FDA-BDAF would be a potential membrane material for desulfurization and controlled release of the S-containing fertilizer.