The thermal degradation of poly（arylene sulfide sulfone）/N-methylpyrrolidone （PASS/NMP） crystal solvate was studied by thermogravimetric analysis （TGA） and was compared with pure PASS in order to determine the w...The thermal degradation of poly（arylene sulfide sulfone）/N-methylpyrrolidone （PASS/NMP） crystal solvate was studied by thermogravimetric analysis （TGA） and was compared with pure PASS in order to determine the way in which the formation of the crystal solvate affected the thermal properties of the polymer. The activation energy of the solid state process was determined using Kissinger＇s method, which does not require knowledge of the reaction mechanism （RM）, to be 174.18 kJ/mol which was lower than that for pure PASS （E = 214 kJ/mol）. The study of master curves together with interpretation of integral methods, allows confirmation that the thermal degradation mechanism for PASS in the crystal solvate system is a decelerated Rn type, which is a solid-state process based on a phase boundary controlled reaction, in the conversion range considered. Whereas, the pure PASS follows a decelerated Dn thermodegradation mechanism in the same conversion range.展开更多
Owing to the excellent filtration performance and low energy cost,polymeric nanofibers microfiltration(MF)membranes have attracted increasing attentions.Poly(arylene sulfide sulfone)(PASS),as one of the structurally m...Owing to the excellent filtration performance and low energy cost,polymeric nanofibers microfiltration(MF)membranes have attracted increasing attentions.Poly(arylene sulfide sulfone)(PASS),as one of the structurally modified polymers based on poly-(phenylene sulfide)(PPS),has been selected as the raw material to fabricate nanofibers MF membranes via electrospun techniques.The effects of PASS solution and the electrospinning processing parameters on the structural morphology of nanofibers were investigated in detail.The average diameter of PASS nanofibers was(296±46)nm under the optimal condition:polymer concentration of 0.27 g·m L^–1 PASS/DMI,applied voltage of 20 kV,and speed of collector drum of 300 r·min^–1.And then the multi-layer PASS nanofibers MF membranes were fabricated from cold-pressing the optimized PASS nanofibers(as-prepared PASS nanofibers)membrane.The morphology,porosity,pore size,mechanical properties,and surface wettability of the multi-layer PASS nanofibers MF membranes could be tuned by the layers of as-prepared nanofibers membrane.The results demonstrated that the membrane with 6 layers(marked as PASS-6)exhibited the smallest porosity,smallest pore size,highest mechanical property,and best surface wettability.Meanwhile,the multi-layer PASS nanofibers MF membranes showed that the rejection ratio gradually increased,while the pure water flux decreased with increasing membranes thickness.The PASS-6 membrane exhibited large water flux of 747.76 L·m^–2·h^–1 and high separation efficiency of 99.9%to 0.2μm particles,making it a promising candidate for microfilter.展开更多
基金supported by the 863 program of China(No.2007AA 03Z561)
文摘The thermal degradation of poly（arylene sulfide sulfone）/N-methylpyrrolidone （PASS/NMP） crystal solvate was studied by thermogravimetric analysis （TGA） and was compared with pure PASS in order to determine the way in which the formation of the crystal solvate affected the thermal properties of the polymer. The activation energy of the solid state process was determined using Kissinger＇s method, which does not require knowledge of the reaction mechanism （RM）, to be 174.18 kJ/mol which was lower than that for pure PASS （E = 214 kJ/mol）. The study of master curves together with interpretation of integral methods, allows confirmation that the thermal degradation mechanism for PASS in the crystal solvate system is a decelerated Rn type, which is a solid-state process based on a phase boundary controlled reaction, in the conversion range considered. Whereas, the pure PASS follows a decelerated Dn thermodegradation mechanism in the same conversion range.
文摘Owing to the excellent filtration performance and low energy cost,polymeric nanofibers microfiltration(MF)membranes have attracted increasing attentions.Poly(arylene sulfide sulfone)(PASS),as one of the structurally modified polymers based on poly-(phenylene sulfide)(PPS),has been selected as the raw material to fabricate nanofibers MF membranes via electrospun techniques.The effects of PASS solution and the electrospinning processing parameters on the structural morphology of nanofibers were investigated in detail.The average diameter of PASS nanofibers was(296±46)nm under the optimal condition:polymer concentration of 0.27 g·m L^–1 PASS/DMI,applied voltage of 20 kV,and speed of collector drum of 300 r·min^–1.And then the multi-layer PASS nanofibers MF membranes were fabricated from cold-pressing the optimized PASS nanofibers(as-prepared PASS nanofibers)membrane.The morphology,porosity,pore size,mechanical properties,and surface wettability of the multi-layer PASS nanofibers MF membranes could be tuned by the layers of as-prepared nanofibers membrane.The results demonstrated that the membrane with 6 layers(marked as PASS-6)exhibited the smallest porosity,smallest pore size,highest mechanical property,and best surface wettability.Meanwhile,the multi-layer PASS nanofibers MF membranes showed that the rejection ratio gradually increased,while the pure water flux decreased with increasing membranes thickness.The PASS-6 membrane exhibited large water flux of 747.76 L·m^–2·h^–1 and high separation efficiency of 99.9%to 0.2μm particles,making it a promising candidate for microfilter.
