In this article, the synthesis and characterization of a novel fluoromonomer and its copolymer with acrylamide is reported. 2-perfluoroamyl-4-hydroxylquinoline 2 was synthesized from ethyl 2, 2-dihydroperfluoroheptano...In this article, the synthesis and characterization of a novel fluoromonomer and its copolymer with acrylamide is reported. 2-perfluoroamyl-4-hydroxylquinoline 2 was synthesized from ethyl 2, 2-dihydroperfluoroheptanoate in high yields. The monomer 4 was then synthesized from 2 in two steps readily in high yields. Synthesis and characterization of copolymers of acrylamide (AM) and the fluoromonomer were investigated. The composition and intrinsic viscosity of these copolymers were studied. It was found that the rheological properties of aqueous solutions of polyacrylamide were modified significantly when a small proportion of the fluoromonomer 4 was incorporated on investigating the viscosity-concentration profiles, pseudoplasticity of these solutions and the effect of the presence of surfactant. These results could be explained by the hydrophobic association of the fluorocarbon segments in the aqueous solutions of these copolymers.展开更多
Two novel fluorine-containing cyclophanes 1 and 2 incorporating a 1,4-bismethylfluorophenylene subunits have been synthesized via the template-directed clipping methodology and their structure was characterized by ~1H...Two novel fluorine-containing cyclophanes 1 and 2 incorporating a 1,4-bismethylfluorophenylene subunits have been synthesized via the template-directed clipping methodology and their structure was characterized by ~1H NMR,^(13)C NMR, MALDI-TOF-MS and elemental analysis.X-ray diffraction analysis of the solid state molecular structure showed that the complex units are linked by non-classical C-H…F hydrogen bonding.展开更多
Poly（ether ether ketone）s（PEEK） are a class of high performance engineering thermoplastics known for their excellent thermal, mechanical, and electrical properties. This class of advanced materials has currently r...Poly（ether ether ketone）s（PEEK） are a class of high performance engineering thermoplastics known for their excellent thermal, mechanical, and electrical properties. This class of advanced materials has currently received considerable attention for potential application in aerospace, electronics, automobile and other high technology fields. However, it is difficult for PEEK to be processed because of their high melting temperature and poor solubility.展开更多
Four novel bridged dianilines containing fluorine were synthesized using 4-chloro-3, 5-dinitrobenzotrifluoride and diamine by two step condensation and reduction. The structures of corresponding compounds were determi...Four novel bridged dianilines containing fluorine were synthesized using 4-chloro-3, 5-dinitrobenzotrifluoride and diamine by two step condensation and reduction. The structures of corresponding compounds were determined by means of IR, NMR and elemental analysis.展开更多
Copolyesters of phosphorus - containing flame - retardant poly(Ethylene Terephthalate) (PET) have been prepared and characterized with the objection of producing an effective, environmentally friendly, nonfugitive alt...Copolyesters of phosphorus - containing flame - retardant poly(Ethylene Terephthalate) (PET) have been prepared and characterized with the objection of producing an effective, environmentally friendly, nonfugitive alternatives to halogen flame retardant system for practical application. With means of NMR, DSC, DTA/TGA, SEM and LOI, structure, thermal property and flam-mability are investigated which reveal that the flame -retardant PET when copolymerized with 2 - carboxyethyl (phenylphosphinic) acid (CEPP) confers excellent fire retardancy with LOI 】 28, broader thermal degradation temperature and increased char formation.展开更多
Geometry optimization at the B3LYP/6-31＋＋G＊ level of theory has been undertaken on clusters containing L-Met （L-methionine） or L-Cys （L-cysteine） surrounded by eight water molecules. The comparison of the struc...Geometry optimization at the B3LYP/6-31＋＋G＊ level of theory has been undertaken on clusters containing L-Met （L-methionine） or L-Cys （L-cysteine） surrounded by eight water molecules. The comparison of the structural parameters of L-Met and L-Cys with X-ray experimental values is in good agreement within 4.8%. This result shows that the privileged positions of water molecules and the possible hydrogen bonding network formed around the backbone of both AAs （amino acids） are adequate. Subsequent calculations of the harmonic vibrational modes followed by a post-processing treatment enable us to assign the vibrational modes of L-Met and L-Cys surrounded explicitly by eight water molecules. The frequencies of the assigned modes are in good agreement with available IR （infra red） and Raman values within 5%.展开更多
In this paper, we combined high-end cationic UV-curable material with fluorinated chain obtaining a series of new fluorine-containing aromatic oxetane monomers via a mild nucleophilic substitution reaction. The struct...In this paper, we combined high-end cationic UV-curable material with fluorinated chain obtaining a series of new fluorine-containing aromatic oxetane monomers via a mild nucleophilic substitution reaction. The structures and properties of monomers were characterized using ~1 H-NMR, ^（19） F-NMR, dynamic viscosity tests and differential scanning calorimetry（DSC）. It was determined that all of the fluorinated monomers obtained had much lower viscosity and higher thermostability after the introduction of hexafluorobenzene. Then, UV-curable coatings were prepared using four fluorine-containing aromatic oxetane monomers（FOX1-4）; the UV-curing kinetics, with three kinds of initiators, and properties of the cured films were evaluated using real-time Fourier transform infrared（FTIR） spectroscopy, water and diiodomethane contact angle tests, surface energy calculations and scanning electron microscopy（SEM）. The FTIR spectroscopy results showed that the coatings possessed excellent conversion rate（〉 99% with liquid initiator PAG-201 in 150 s）, and as the fluorine content increased, the monomers exhibited decreased mobility with the increasing viscosity and worse solubility with fluorinated monomers, resulting in a lower conversion rate. Moreover, the coatings possessed favorable hydrophobic and oleophobic properties and low surface energies owing to the fluoride chains floating to the membrane-air interface, which was also confirmed by discrete concave structures in SEM images. These new kinds of monomers can replace traditional fluorinated cationic monomers applied to the fingerprint resistant, fouling resistant, scratch resistant and anti-aging coatings, adhesives or printing ink materials.展开更多
Title Compond-5 chloro 2,4,6 trifluoro 1,3 bezenedicarbonitrile was prepared by fluoration exchange reaction under comparatively mild condition with yield 81%;various reactive conditions,as well as its possible by pro...Title Compond-5 chloro 2,4,6 trifluoro 1,3 bezenedicarbonitrile was prepared by fluoration exchange reaction under comparatively mild condition with yield 81%;various reactive conditions,as well as its possible by products,were discussed in detail.The structure of the target compound was confirmed by excluding its two isomers based on IR,MS, 13 CNMR,and 19 FNMR data.展开更多
2,2,3,3-tetrafluoropropyl acrylate(TFPA)was prepared by esterification of acrylic acid and 2,2,3,3-tetrafluoropropanol in the presence of polymerization retarder,dehydration agent and concentrated sulfuric acid.The ef...2,2,3,3-tetrafluoropropyl acrylate(TFPA)was prepared by esterification of acrylic acid and 2,2,3,3-tetrafluoropropanol in the presence of polymerization retarder,dehydration agent and concentrated sulfuric acid.The effect of polymerization retarader,the amount of sulfuric acid and reaction duration on the yield of TFPA was reported.The results showed that the yield of TPFE was 65～70% based on the theoretical calculation under optimized experimental conditions.展开更多
基金Project supported by National Natural Science Foundation,Grant approval numbers 29472074 and 29632003
文摘In this article, the synthesis and characterization of a novel fluoromonomer and its copolymer with acrylamide is reported. 2-perfluoroamyl-4-hydroxylquinoline 2 was synthesized from ethyl 2, 2-dihydroperfluoroheptanoate in high yields. The monomer 4 was then synthesized from 2 in two steps readily in high yields. Synthesis and characterization of copolymers of acrylamide (AM) and the fluoromonomer were investigated. The composition and intrinsic viscosity of these copolymers were studied. It was found that the rheological properties of aqueous solutions of polyacrylamide were modified significantly when a small proportion of the fluoromonomer 4 was incorporated on investigating the viscosity-concentration profiles, pseudoplasticity of these solutions and the effect of the presence of surfactant. These results could be explained by the hydrophobic association of the fluorocarbon segments in the aqueous solutions of these copolymers.
基金support from the National Natural Science Foundation of China(No.20872051)
文摘Two novel fluorine-containing cyclophanes 1 and 2 incorporating a 1,4-bismethylfluorophenylene subunits have been synthesized via the template-directed clipping methodology and their structure was characterized by ~1H NMR,^(13)C NMR, MALDI-TOF-MS and elemental analysis.X-ray diffraction analysis of the solid state molecular structure showed that the complex units are linked by non-classical C-H…F hydrogen bonding.
基金Supported by the Natural Science Foundation of Beij ing City,China(No.2062021)
文摘Poly（ether ether ketone）s（PEEK） are a class of high performance engineering thermoplastics known for their excellent thermal, mechanical, and electrical properties. This class of advanced materials has currently received considerable attention for potential application in aerospace, electronics, automobile and other high technology fields. However, it is difficult for PEEK to be processed because of their high melting temperature and poor solubility.
基金Supported by the Key Scientific Research Founda-tion of Education Development of Hunan Province (02A036)Sci-ence and Technology Program Foundation of Hunan Province(03JZY3042)
文摘Four novel bridged dianilines containing fluorine were synthesized using 4-chloro-3, 5-dinitrobenzotrifluoride and diamine by two step condensation and reduction. The structures of corresponding compounds were determined by means of IR, NMR and elemental analysis.
基金Sponsored by Notional Natural Scicnce Foundation of China(No.59203027)
文摘Copolyesters of phosphorus - containing flame - retardant poly(Ethylene Terephthalate) (PET) have been prepared and characterized with the objection of producing an effective, environmentally friendly, nonfugitive alternatives to halogen flame retardant system for practical application. With means of NMR, DSC, DTA/TGA, SEM and LOI, structure, thermal property and flam-mability are investigated which reveal that the flame -retardant PET when copolymerized with 2 - carboxyethyl (phenylphosphinic) acid (CEPP) confers excellent fire retardancy with LOI 】 28, broader thermal degradation temperature and increased char formation.
文摘Geometry optimization at the B3LYP/6-31＋＋G＊ level of theory has been undertaken on clusters containing L-Met （L-methionine） or L-Cys （L-cysteine） surrounded by eight water molecules. The comparison of the structural parameters of L-Met and L-Cys with X-ray experimental values is in good agreement within 4.8%. This result shows that the privileged positions of water molecules and the possible hydrogen bonding network formed around the backbone of both AAs （amino acids） are adequate. Subsequent calculations of the harmonic vibrational modes followed by a post-processing treatment enable us to assign the vibrational modes of L-Met and L-Cys surrounded explicitly by eight water molecules. The frequencies of the assigned modes are in good agreement with available IR （infra red） and Raman values within 5%.
基金financially supported by the National Natural Science Foundation of China (No. 21574014)
文摘In this paper, we combined high-end cationic UV-curable material with fluorinated chain obtaining a series of new fluorine-containing aromatic oxetane monomers via a mild nucleophilic substitution reaction. The structures and properties of monomers were characterized using ~1 H-NMR, ^（19） F-NMR, dynamic viscosity tests and differential scanning calorimetry（DSC）. It was determined that all of the fluorinated monomers obtained had much lower viscosity and higher thermostability after the introduction of hexafluorobenzene. Then, UV-curable coatings were prepared using four fluorine-containing aromatic oxetane monomers（FOX1-4）; the UV-curing kinetics, with three kinds of initiators, and properties of the cured films were evaluated using real-time Fourier transform infrared（FTIR） spectroscopy, water and diiodomethane contact angle tests, surface energy calculations and scanning electron microscopy（SEM）. The FTIR spectroscopy results showed that the coatings possessed excellent conversion rate（〉 99% with liquid initiator PAG-201 in 150 s）, and as the fluorine content increased, the monomers exhibited decreased mobility with the increasing viscosity and worse solubility with fluorinated monomers, resulting in a lower conversion rate. Moreover, the coatings possessed favorable hydrophobic and oleophobic properties and low surface energies owing to the fluoride chains floating to the membrane-air interface, which was also confirmed by discrete concave structures in SEM images. These new kinds of monomers can replace traditional fluorinated cationic monomers applied to the fingerprint resistant, fouling resistant, scratch resistant and anti-aging coatings, adhesives or printing ink materials.
文摘Title Compond-5 chloro 2,4,6 trifluoro 1,3 bezenedicarbonitrile was prepared by fluoration exchange reaction under comparatively mild condition with yield 81%;various reactive conditions,as well as its possible by products,were discussed in detail.The structure of the target compound was confirmed by excluding its two isomers based on IR,MS, 13 CNMR,and 19 FNMR data.
文摘2,2,3,3-tetrafluoropropyl acrylate(TFPA)was prepared by esterification of acrylic acid and 2,2,3,3-tetrafluoropropanol in the presence of polymerization retarder,dehydration agent and concentrated sulfuric acid.The effect of polymerization retarader,the amount of sulfuric acid and reaction duration on the yield of TFPA was reported.The results showed that the yield of TPFE was 65～70% based on the theoretical calculation under optimized experimental conditions.
