A fluorine containing monomer was synthesized and its polymer was prepared by aromatic nucleophilic substitution polycondensation of the monomer and 4,4′ difluorobenzophenone using potassium carbonate as the catalyst...A fluorine containing monomer was synthesized and its polymer was prepared by aromatic nucleophilic substitution polycondensation of the monomer and 4,4′ difluorobenzophenone using potassium carbonate as the catalyst and tetramethylene sulfone as solvent. The polymer properties were characterized by FTIR, NMR, DSC and the results showed that the T g of the polymer is 141 ℃ and the solubility of the polymer was obviously improved due to the introduction of (3 trifluoromethyl)phenyl group.展开更多
A novel polyimide(PI) containing pendent biphenyl ester groups was synthesized from 3,5-diaminobenzoic-4′-biphenyl ester (DABBE)and 3,3′,4,4′-oxydiphthalic dianhydride(ODPA) by a one-step high-temperature polyconde...A novel polyimide(PI) containing pendent biphenyl ester groups was synthesized from 3,5-diaminobenzoic-4′-biphenyl ester (DABBE)and 3,3′,4,4′-oxydiphthalic dianhydride(ODPA) by a one-step high-temperature polycondensation in m-cresol.This PI is a semicrystalline polymer.Lots of short fine fibric crystals with length and diameter about 20、μm and 1、μm respectively disperse randomly in the PI film. The optical textures and the X-ray diffraction patterns of the PI solution and film show that the PI main chains are in the extended conformation and pack parallel to each other, and the pendent biphenyl ester groups occupy the space between the main chain layers,more or less perpendicular to the main chains.At the same time, mechanical and thermally stable properties of the PI film were investigated. The excellent mechanical properties of general polyimide films are reasonably maintained, the polyimide film with pendent groups showes higher tensile strength and modulus and lower T g. TGA study showes a typical two-step weight loss behavior corresponding to the pyrolysis of pendent groups and main chains of the PI,respectively.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
文摘A fluorine containing monomer was synthesized and its polymer was prepared by aromatic nucleophilic substitution polycondensation of the monomer and 4,4′ difluorobenzophenone using potassium carbonate as the catalyst and tetramethylene sulfone as solvent. The polymer properties were characterized by FTIR, NMR, DSC and the results showed that the T g of the polymer is 141 ℃ and the solubility of the polymer was obviously improved due to the introduction of (3 trifluoromethyl)phenyl group.
文摘A novel polyimide(PI) containing pendent biphenyl ester groups was synthesized from 3,5-diaminobenzoic-4′-biphenyl ester (DABBE)and 3,3′,4,4′-oxydiphthalic dianhydride(ODPA) by a one-step high-temperature polycondensation in m-cresol.This PI is a semicrystalline polymer.Lots of short fine fibric crystals with length and diameter about 20、μm and 1、μm respectively disperse randomly in the PI film. The optical textures and the X-ray diffraction patterns of the PI solution and film show that the PI main chains are in the extended conformation and pack parallel to each other, and the pendent biphenyl ester groups occupy the space between the main chain layers,more or less perpendicular to the main chains.At the same time, mechanical and thermally stable properties of the PI film were investigated. The excellent mechanical properties of general polyimide films are reasonably maintained, the polyimide film with pendent groups showes higher tensile strength and modulus and lower T g. TGA study showes a typical two-step weight loss behavior corresponding to the pyrolysis of pendent groups and main chains of the PI,respectively.
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.
