We synthesized a series of polymers: poly(ether ether ketone ketone) (PEEKK),poly (ether biphenyl ether ketone ketone) (PEBEKK) and their copolymer by polycondensation. We also prepared a series of PEEKK-PEBEKK blends...We synthesized a series of polymers: poly(ether ether ketone ketone) (PEEKK),poly (ether biphenyl ether ketone ketone) (PEBEKK) and their copolymer by polycondensation. We also prepared a series of PEEKK-PEBEKK blends. By using DSC method, we found that Tg of the copolymers and the blends rose with the increasing of biphenyl contents in the polymers. Tc of the copolymers and the blends is higher than the corresponding homopolymer. From the results, we think that PEEKK-PEBEKK copolymer and blends are miscible and the copolymer is random.展开更多
Poly(aryl ether ether ketone ketone)(PEEKK) is a kind important high-performance polymers due to their excellent thermal stability a nd other outstanding properties similar to PEEK and PEKK.However,the PEEKK’s ins ol...Poly(aryl ether ether ketone ketone)(PEEKK) is a kind important high-performance polymers due to their excellent thermal stability a nd other outstanding properties similar to PEEK and PEKK.However,the PEEKK’s ins olubility in common solutions and high melt point restrict its processing and ap plications.In this paper,a series of random copolymers composed of poly(aryl eth er ether ketone ketone)(PEEKK)/poly(aryl ether ketone ether ketone ketone) cont a ining bis(o-metheyl) moiety(DM-PEKEKK) were prepared by low temperatur e so lution polycondensation of 4,4′-bis(2,6-dimethylphenoxy)diphenylketone (o -M 2DPOBP),1,4-dipheoxylbenzene(DPB) and terephthaloyl chlorde(TPC) in 1,2 -dichloroethane with the presence of AlCl 3 and DMF. The copolymers were chara cterized by FT-IR,DSC,WAXD,TGA,etc.The results show that glass transitio n te mperature increases greatly with the increasing of the ratio of o-M 2DPOBP /DPB,while melting temperature and crystallinity of copolymers decrease.The solu bility of the copolymers is improved greatly,while the copolymers still exhibit excellent thermostability.展开更多
A new kind of high performance composite resin matrix PEEK/PES, PEEKK/PES block copolymers have been prepared from the corresponding oligomers via a nucleophilic aromatic substitution reaction. The different propertie...A new kind of high performance composite resin matrix PEEK/PES, PEEKK/PES block copolymers have been prepared from the corresponding oligomers via a nucleophilic aromatic substitution reaction. The different properties of the copolymers are investigated by differential scanning calorimetry (d. s. c), thermogravimetric analysis (t. g. a) and dynamic mechanical analysis (d. m. a). The results show that the relationship between Tg and the compositions of the copolymers approximately follows the formula 1/Tg=W1/Tg1 +W2/Tg2 for PEEKK/PES block copolymers, and Tg=Tg1W1 +Tg2W2 for PEEK/PES block copolymers. The PES content and the segment length of the copolymers have a significant influence on their melting point. The thermal properties and dynamic mechanical behaviour of the copolymers are also studied. The introduction of PES segment into the molecular main chain increases the glass transition temperature of poly aryl ether ketones and decreases their melting temperature, that is to say it decreases their melting processing temperature. The block copolymers keep the high temperature stability and solvent resistance of poly aryl ether ketones. They are expected to be a new kind of high performance composite resin matrix.展开更多
In this paper, melt crystallization of poly(ether ether ketone ketone)(PEEKK) under strong electric field was investigated. In the crystal structure of PEEKK, the length of c axis was found to be 1.075 nm, increasing ...In this paper, melt crystallization of poly(ether ether ketone ketone)(PEEKK) under strong electric field was investigated. In the crystal structure of PEEKK, the length of c axis was found to be 1.075 nm, increasing by 7% compared to that of PEEKK crystallized without strong electric field. The molecule chains might take a more extended conformation through the opening of the bridge bond angles by increasing from 124° to 144° under strong electric field in the crystal structure.展开更多
An imidazolium functionalized poly(ether ether ketone ketone)(PEEKK-DIm OH)anion exchange membrane(AEM)readily soluble in certain low-boiling-point solvents(isopropanol)is prepared.The solubility results are consisten...An imidazolium functionalized poly(ether ether ketone ketone)(PEEKK-DIm OH)anion exchange membrane(AEM)readily soluble in certain low-boiling-point solvents(isopropanol)is prepared.The solubility results are consistent with the results of molecular dynamics simulations.By varying the chloromethylation reaction temperature or concentrated sulfuric acid concentration of PEEKK,the degrees of chloromethylation of PEEKK are changed from 54% to 92%,the corresponding PEEKK-DIm OH AEMs with the ion exchange capacities(IECs)of 1.14–1.65 mmol·g^(-1).The PEEKK-DIm OH 92% AEM shows high hydroxide conductivity(31 m S·cm^(-1)),suitable water uptake(94%)and acceptable swelling ratio(39%)at 60°C.In addition,the PEEKK-DIm OH AEMs possess good thermal and alkaline stability.The maximum power density(46.16 mW·cm^(-2))of fuel cell prepared with PEEKK-DIm OH 92%AEM as exchange membrane and ionomer is much higher than that with commercial AHA membranes.All the above results indicate that the PEEKK used in this study is a promising AEM matrix material for alkaline fuel cells.展开更多
文摘We synthesized a series of polymers: poly(ether ether ketone ketone) (PEEKK),poly (ether biphenyl ether ketone ketone) (PEBEKK) and their copolymer by polycondensation. We also prepared a series of PEEKK-PEBEKK blends. By using DSC method, we found that Tg of the copolymers and the blends rose with the increasing of biphenyl contents in the polymers. Tc of the copolymers and the blends is higher than the corresponding homopolymer. From the results, we think that PEEKK-PEBEKK copolymer and blends are miscible and the copolymer is random.
文摘Poly(aryl ether ether ketone ketone)(PEEKK) is a kind important high-performance polymers due to their excellent thermal stability a nd other outstanding properties similar to PEEK and PEKK.However,the PEEKK’s ins olubility in common solutions and high melt point restrict its processing and ap plications.In this paper,a series of random copolymers composed of poly(aryl eth er ether ketone ketone)(PEEKK)/poly(aryl ether ketone ether ketone ketone) cont a ining bis(o-metheyl) moiety(DM-PEKEKK) were prepared by low temperatur e so lution polycondensation of 4,4′-bis(2,6-dimethylphenoxy)diphenylketone (o -M 2DPOBP),1,4-dipheoxylbenzene(DPB) and terephthaloyl chlorde(TPC) in 1,2 -dichloroethane with the presence of AlCl 3 and DMF. The copolymers were chara cterized by FT-IR,DSC,WAXD,TGA,etc.The results show that glass transitio n te mperature increases greatly with the increasing of the ratio of o-M 2DPOBP /DPB,while melting temperature and crystallinity of copolymers decrease.The solu bility of the copolymers is improved greatly,while the copolymers still exhibit excellent thermostability.
文摘A new kind of high performance composite resin matrix PEEK/PES, PEEKK/PES block copolymers have been prepared from the corresponding oligomers via a nucleophilic aromatic substitution reaction. The different properties of the copolymers are investigated by differential scanning calorimetry (d. s. c), thermogravimetric analysis (t. g. a) and dynamic mechanical analysis (d. m. a). The results show that the relationship between Tg and the compositions of the copolymers approximately follows the formula 1/Tg=W1/Tg1 +W2/Tg2 for PEEKK/PES block copolymers, and Tg=Tg1W1 +Tg2W2 for PEEK/PES block copolymers. The PES content and the segment length of the copolymers have a significant influence on their melting point. The thermal properties and dynamic mechanical behaviour of the copolymers are also studied. The introduction of PES segment into the molecular main chain increases the glass transition temperature of poly aryl ether ketones and decreases their melting temperature, that is to say it decreases their melting processing temperature. The block copolymers keep the high temperature stability and solvent resistance of poly aryl ether ketones. They are expected to be a new kind of high performance composite resin matrix.
文摘In this paper, melt crystallization of poly(ether ether ketone ketone)(PEEKK) under strong electric field was investigated. In the crystal structure of PEEKK, the length of c axis was found to be 1.075 nm, increasing by 7% compared to that of PEEKK crystallized without strong electric field. The molecule chains might take a more extended conformation through the opening of the bridge bond angles by increasing from 124° to 144° under strong electric field in the crystal structure.
基金Supported by the National Natural Science Foundation of China(21706023,21476044,21406031)the National Key Research and Development Program of China(2016YFB0101203)+2 种基金Education Department of Liaoning Province of China(LT2015007)Fundamental Research Funds for the Central Universities(DUT16TD19)the Changjiang Scholars Program(T2012049)
文摘An imidazolium functionalized poly(ether ether ketone ketone)(PEEKK-DIm OH)anion exchange membrane(AEM)readily soluble in certain low-boiling-point solvents(isopropanol)is prepared.The solubility results are consistent with the results of molecular dynamics simulations.By varying the chloromethylation reaction temperature or concentrated sulfuric acid concentration of PEEKK,the degrees of chloromethylation of PEEKK are changed from 54% to 92%,the corresponding PEEKK-DIm OH AEMs with the ion exchange capacities(IECs)of 1.14–1.65 mmol·g^(-1).The PEEKK-DIm OH 92% AEM shows high hydroxide conductivity(31 m S·cm^(-1)),suitable water uptake(94%)and acceptable swelling ratio(39%)at 60°C.In addition,the PEEKK-DIm OH AEMs possess good thermal and alkaline stability.The maximum power density(46.16 mW·cm^(-2))of fuel cell prepared with PEEKK-DIm OH 92%AEM as exchange membrane and ionomer is much higher than that with commercial AHA membranes.All the above results indicate that the PEEKK used in this study is a promising AEM matrix material for alkaline fuel cells.
