High molecular weight copoly(ether ketone)s (PEK) based on 4-(4-hydroxyphenyl)-1- phthalazinone (DHPZ)/4,4-thiobisphenol (TBP)/4,4-diflourodiphenylketone (DFK) were prepared by nucleophilic substitution polycondensati...High molecular weight copoly(ether ketone)s (PEK) based on 4-(4-hydroxyphenyl)-1- phthalazinone (DHPZ)/4,4-thiobisphenol (TBP)/4,4-diflourodiphenylketone (DFK) were prepared by nucleophilic substitution polycondensation. The copolymers were characterized by FT-IR and 1H-NMR. Thermal properties and solubility of copolymers were studied.展开更多
It is found in this paper that the dielectric behavior of polyetherketone with cardo group (PEK- C) irradiated at a dose of 2.02 MGy has an obvious change. For the irradiated PEK-C, both the temperature spectrum of di...It is found in this paper that the dielectric behavior of polyetherketone with cardo group (PEK- C) irradiated at a dose of 2.02 MGy has an obvious change. For the irradiated PEK-C, both the temperature spectrum of dielectric loss factor (ε " ) within a range of 20-200 ℃ and the frequency spectrum of dielectric coefficient (ε’) in a range of 30 Hz-1 MHz show that ε" and ε’ increase from 5.4×10-3 to 4.6×10-1 andfrom 3 to 5, respectively.展开更多
The effects of irradiation on the polyetherketone with cardo group (PEK-C) were studied. It was found that PEK-C can be crosslinked by irradiation under vacuum, while degradation reaction occurred in PEK-C at room tem...The effects of irradiation on the polyetherketone with cardo group (PEK-C) were studied. It was found that PEK-C can be crosslinked by irradiation under vacuum, while degradation reaction occurred in PEK-C at room temperature in the presence of air. Moreover. it was also found that Ts value of the crosslinked PEK-C at high temperature is higher than that at room temperature in the case of the same gel content, whose value is about 8℃ higher than that of unirradiated PEK-C. The gelation dose of PEK-C at 300℃ under vacuum is 1.5×10~4 Gy, which is about hundred times smaller than that at room temperature.展开更多
Membranes for gas separation have developed significantly in the last twenty years,however,there is still a need for high temperature and chemically resistant membranes that exhibit good selectivity and gas permeabili...Membranes for gas separation have developed significantly in the last twenty years,however,there is still a need for high temperature and chemically resistant membranes that exhibit good selectivity and gas permeability.Our study examines the fundamental properties of polyetherketone (PEK,a thermally stable and chemically resistant polymer) membranes prepared using concentrated sulphuric acid (98% H_2SO_4) as the solvent.Non-solvents used in the work included acetic acid,ethanol,methanol,glycerol,and water....展开更多
基金This work was supported by the National Natural Science Foundation of China (59473901).
文摘High molecular weight copoly(ether ketone)s (PEK) based on 4-(4-hydroxyphenyl)-1- phthalazinone (DHPZ)/4,4-thiobisphenol (TBP)/4,4-diflourodiphenylketone (DFK) were prepared by nucleophilic substitution polycondensation. The copolymers were characterized by FT-IR and 1H-NMR. Thermal properties and solubility of copolymers were studied.
基金The Project Supported by National Natural Science Foundation of China
文摘It is found in this paper that the dielectric behavior of polyetherketone with cardo group (PEK- C) irradiated at a dose of 2.02 MGy has an obvious change. For the irradiated PEK-C, both the temperature spectrum of dielectric loss factor (ε " ) within a range of 20-200 ℃ and the frequency spectrum of dielectric coefficient (ε’) in a range of 30 Hz-1 MHz show that ε" and ε’ increase from 5.4×10-3 to 4.6×10-1 andfrom 3 to 5, respectively.
文摘The effects of irradiation on the polyetherketone with cardo group (PEK-C) were studied. It was found that PEK-C can be crosslinked by irradiation under vacuum, while degradation reaction occurred in PEK-C at room temperature in the presence of air. Moreover. it was also found that Ts value of the crosslinked PEK-C at high temperature is higher than that at room temperature in the case of the same gel content, whose value is about 8℃ higher than that of unirradiated PEK-C. The gelation dose of PEK-C at 300℃ under vacuum is 1.5×10~4 Gy, which is about hundred times smaller than that at room temperature.
基金the Engineering and Physical Sciences Research Council (EPSRC,No.GR/M56876).
文摘Membranes for gas separation have developed significantly in the last twenty years,however,there is still a need for high temperature and chemically resistant membranes that exhibit good selectivity and gas permeability.Our study examines the fundamental properties of polyetherketone (PEK,a thermally stable and chemically resistant polymer) membranes prepared using concentrated sulphuric acid (98% H_2SO_4) as the solvent.Non-solvents used in the work included acetic acid,ethanol,methanol,glycerol,and water....
