A series of quaternary ammonium ionic liquids(ILs)were synthesized and employed as catalysts for the production of poly(isosorbide carbonate)(PIC)from diphenyl carbonate and isosorbide via a melt polycondensation proc...A series of quaternary ammonium ionic liquids(ILs)were synthesized and employed as catalysts for the production of poly(isosorbide carbonate)(PIC)from diphenyl carbonate and isosorbide via a melt polycondensation process.The relationship between the anions of the ILs and the catalytic activities was investigated,and the readily‐prepared IL tetraethylammonium imidazolate(TEAI)was found to exhibit the highest catalytic activity.After optimizing the reaction conditions,a PIC with a weight‐average molecular weight(Mw)of25600g/mol was obtained,in conjunction with an isosorbide conversion of92%.As a means of modifying the molecular flexibility and thermal properties of the PIC,poly(aliphatic diol‐co‐isosorbide carbonate)s(PAIC)s were successfully synthesized,again using TEAI,and polymers with Mw values ranging from29000to112000g/mol were obtained.13C NMR analyses determined that the PAIC specimens had random microstructures,while differential scanning calorimetry demonstrated that each of the PAICs were amorphous and had glass transition temperatures ranging from50to115°C.Thermogravimetric analyses found Td‐5%values ranging from316to332°C for these polymers.Based on these data,it is evident that the incorporation of linear or cyclohexane‐based diol repeating units changed the thermal properties of the PIC.展开更多
AC impedance spectroscopy in pure room temperature ionic liquids （RTILs） and RTIL-water mixture was measured at the temperature of range from 30 ℃ down to -30 ℃. The cations of RTILs are N,N-diethyl-N-methyl-N-（2...AC impedance spectroscopy in pure room temperature ionic liquids （RTILs） and RTIL-water mixture was measured at the temperature of range from 30 ℃ down to -30 ℃. The cations of RTILs are N,N-diethyl-N-methyl-N-（2-methoxyethyl） ammonium （[DEME]）, 1-ethyl-3-methylimidazolium （[C2mim]） and l-butyl-3-methylimidazolium （[Camim]）, the anions are tetrafluoroborate （[BF4]） and bis（trifluoromethanesulfonyl）imide （[TFSI]）. In all pure RTILs, there are two kinds of local minima in real part of the AC impedance Zreal. By adding water to [DEME][BF4] （0 mol% 〈 x 〈 94 mol%） at room temperature, the local minimum value at higher frequency decreased remarkably at the fixed frequency with increasing water concentration. Above 94 mol% H20, a quite different profile of the AC impedance spectroscopy was obtained. In addition to Zreal. temperature dependence of an imaginary part of the impedance Zimag had an isosbestic point below 94 mol%. The isosbestic point disappeared above 94 mol%. The isosbestic point in Zing reveals an interaction between [DEME][BFa] and H2O.展开更多
1 Results Less-flammability is one of the most valuable properties of ionic liquids (ILs) comprised of perfluoroanions such as BF-4,TFSI-([(CF3SO2)2N]-).Recently,such a unique liquid has been expected to use as an ele...1 Results Less-flammability is one of the most valuable properties of ionic liquids (ILs) comprised of perfluoroanions such as BF-4,TFSI-([(CF3SO2)2N]-).Recently,such a unique liquid has been expected to use as an electrolyte in order to improve thermal stability and longevity of a lithium secondary battery,which have been increasingly required for an application especially to an electric vehicle and a hybrid car.We previously reported that PI13[TFSI] (PI13: N-methyl-N-propylpiperidinium) could be used ...展开更多
基金supported by the National Key Projects for Fundamental Research and Development of China(2016YFB0600903)the National Natural Science Foundation of China(91434107,21506226,21476245)the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(QYZDY-SSW-JSC011)~~
文摘A series of quaternary ammonium ionic liquids(ILs)were synthesized and employed as catalysts for the production of poly(isosorbide carbonate)(PIC)from diphenyl carbonate and isosorbide via a melt polycondensation process.The relationship between the anions of the ILs and the catalytic activities was investigated,and the readily‐prepared IL tetraethylammonium imidazolate(TEAI)was found to exhibit the highest catalytic activity.After optimizing the reaction conditions,a PIC with a weight‐average molecular weight(Mw)of25600g/mol was obtained,in conjunction with an isosorbide conversion of92%.As a means of modifying the molecular flexibility and thermal properties of the PIC,poly(aliphatic diol‐co‐isosorbide carbonate)s(PAIC)s were successfully synthesized,again using TEAI,and polymers with Mw values ranging from29000to112000g/mol were obtained.13C NMR analyses determined that the PAIC specimens had random microstructures,while differential scanning calorimetry demonstrated that each of the PAICs were amorphous and had glass transition temperatures ranging from50to115°C.Thermogravimetric analyses found Td‐5%values ranging from316to332°C for these polymers.Based on these data,it is evident that the incorporation of linear or cyclohexane‐based diol repeating units changed the thermal properties of the PIC.
文摘AC impedance spectroscopy in pure room temperature ionic liquids （RTILs） and RTIL-water mixture was measured at the temperature of range from 30 ℃ down to -30 ℃. The cations of RTILs are N,N-diethyl-N-methyl-N-（2-methoxyethyl） ammonium （[DEME]）, 1-ethyl-3-methylimidazolium （[C2mim]） and l-butyl-3-methylimidazolium （[Camim]）, the anions are tetrafluoroborate （[BF4]） and bis（trifluoromethanesulfonyl）imide （[TFSI]）. In all pure RTILs, there are two kinds of local minima in real part of the AC impedance Zreal. By adding water to [DEME][BF4] （0 mol% 〈 x 〈 94 mol%） at room temperature, the local minimum value at higher frequency decreased remarkably at the fixed frequency with increasing water concentration. Above 94 mol% H20, a quite different profile of the AC impedance spectroscopy was obtained. In addition to Zreal. temperature dependence of an imaginary part of the impedance Zimag had an isosbestic point below 94 mol%. The isosbestic point disappeared above 94 mol%. The isosbestic point in Zing reveals an interaction between [DEME][BFa] and H2O.
文摘1 Results Less-flammability is one of the most valuable properties of ionic liquids (ILs) comprised of perfluoroanions such as BF-4,TFSI-([(CF3SO2)2N]-).Recently,such a unique liquid has been expected to use as an electrolyte in order to improve thermal stability and longevity of a lithium secondary battery,which have been increasingly required for an application especially to an electric vehicle and a hybrid car.We previously reported that PI13[TFSI] (PI13: N-methyl-N-propylpiperidinium) could be used ...
