In this paper,we overview beifely some of our key projects that had contridubted to modifyprevious author’s conclusions and put forward new viewpoints that are being underinvestigation.The novel ideas worth mentionin...In this paper,we overview beifely some of our key projects that had contridubted to modifyprevious author’s conclusions and put forward new viewpoints that are being underinvestigation.The novel ideas worth mentioning are the calculation of the sequence distributionon the copolymerization with a new version of probability suggested,the characterization of stepgrowth polymerization that indicates the MDW may not be continuous in theory,and after all,the Nylon 6 polymerization engineering exploitation where the concept of water activity is usedin place of concentration so as to extend the applicability’of the kinetic model proposed previous-ly.展开更多
The exploitation of new green polymerization avenues for the effective synthesis of polymers by reversible-deactivation radical polymerization plays a critical role in pursuing the development of polymeric materials.I...The exploitation of new green polymerization avenues for the effective synthesis of polymers by reversible-deactivation radical polymerization plays a critical role in pursuing the development of polymeric materials.In this work,serials of deep eutectic solvents(DES)with intermolecular-hydrogen-bonding interaction were constructed as catalysts and medium for actuating reversible complexation-mediated polymerization(RCMP)for the first time,yielding methacrylate polymers with high monomer conversion and narrow dispersion molecular weight in both water and oil systems.The mechanism and elementary reaction of RCMP were explored deeply,revealing that the complexation of initiator with DES to generate radicals was a ratecontrolling step and intermolecular-hydrogen-bond was primary factor to influence polymerization rate.Moreover,the insights of density functional theory calculations revealed that negative electrostatic potential ensured nucleophilic capacity.This investigation demonstrated the considerable potential of DES for RCMP,which is anticipated for other polymerization applications as a novel medium mode.展开更多
A mathematical model has been developed to handle the reactions in Poly(ethylene terephthalate) (PET) undergoing polycondensation reactions in the solid state. The effect of temperature on chain mobility was considere...A mathematical model has been developed to handle the reactions in Poly(ethylene terephthalate) (PET) undergoing polycondensation reactions in the solid state. The effect of temperature on chain mobility was considered to estimate the rate constants of chemical reactions. The polymer crystalline fraction is modeled as containing only repeat units, thus concentrating end groups and conden-sates in the amorphous fraction. This model is compared with PET reaction data with good results.展开更多
Chiral polymer was synthesized by the polymerization of （R）-6,6＇-bistributylstannyl-2,2＇-binaphtho-20-crown-6 （M-1） with 1,4-dibromo-2,3-bisbutoxy-naphthyl （M-2） by Pd（PPhs）4 catalyzed Stille coupling reacti...Chiral polymer was synthesized by the polymerization of （R）-6,6＇-bistributylstannyl-2,2＇-binaphtho-20-crown-6 （M-1） with 1,4-dibromo-2,3-bisbutoxy-naphthyl （M-2） by Pd（PPhs）4 catalyzed Stille coupling reaction. Both monomer and polymer were analyzed by NMR, MS, FT-IR, UV, polarimetry, DSC-TGA, CD, fluorescent spectroscopy and GPC. The major difference between monomer and polymer is that a long wavelength Cotton Effect was observed for the polymer due to its more extended conjugation in the repeating unit and a highly rigid backbone in the polymer chain. Polymer has strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the repeating unit of the polymer to the chiral binaphthyl core and is expected to have potential application in the materials of fluorescent sensors and chiral chromatographic packing for resolution ofracemic amino acid.展开更多
A new conjugated copolymer （PTST-DyOXD） derived from 1,1-dimethyl-3,4-diphenyl-2,5-bis（5-bromo-2- thienyl）-silole （TST） and 2,5-bis（4-ethynylphenyl）-l,3,4-oxadiazole （DyOXD） was synthesized by Pd（0）-cataly...A new conjugated copolymer （PTST-DyOXD） derived from 1,1-dimethyl-3,4-diphenyl-2,5-bis（5-bromo-2- thienyl）-silole （TST） and 2,5-bis（4-ethynylphenyl）-l,3,4-oxadiazole （DyOXD） was synthesized by Pd（0）-catalyzed Sonogashira coupling reaction. For comparison, another copolymer without acetenyl group （PTST-OXD） was also synthesized by Pd（0）-catalyzed Suzuki coupling reaction. Chemical structures and optoelectronic properties of the copolymers were characterized by IH NMR, 13C NMR, IR, UV-vis absorption, photoluminescence and cyclic voltammetry. The number-average molecular weight （Mn） is 4010 Da for PTST-DyOXD and 3890 Da for PTST-OXD, respectively. The thermogravimetric analysis （TGA） measurements show that they have good thermal stability with decomposition temperature at 312 and 318 ~C, respectively. The optical band gap is 2.21 eV for PTST-DyOXD and 2.10 eV for PTST-OXD based on the absorption onset. CV analysis revealed the LUMO level of PTST-DyOXD is -3.04 eV, lower than that of PTST-OXD （about -2.89 eV）, which is attributed to the introduction of acetylene group in PTST-DyOXD, increasing the system of the conjugate chain length.展开更多
文摘In this paper,we overview beifely some of our key projects that had contridubted to modifyprevious author’s conclusions and put forward new viewpoints that are being underinvestigation.The novel ideas worth mentioning are the calculation of the sequence distributionon the copolymerization with a new version of probability suggested,the characterization of stepgrowth polymerization that indicates the MDW may not be continuous in theory,and after all,the Nylon 6 polymerization engineering exploitation where the concept of water activity is usedin place of concentration so as to extend the applicability’of the kinetic model proposed previous-ly.
基金financially supported by the State Key Program of National Natural Science Foundation of China(U21A20313)the Key Program of Qingyuan Innovation Laboratory(00221003)+2 种基金the“111”Program of Fuzhou Universitythe Natural Science Foundation of Fujian Province(2019J05040)the China Postdoctoral Science Foundation(2022M20739)。
文摘The exploitation of new green polymerization avenues for the effective synthesis of polymers by reversible-deactivation radical polymerization plays a critical role in pursuing the development of polymeric materials.In this work,serials of deep eutectic solvents(DES)with intermolecular-hydrogen-bonding interaction were constructed as catalysts and medium for actuating reversible complexation-mediated polymerization(RCMP)for the first time,yielding methacrylate polymers with high monomer conversion and narrow dispersion molecular weight in both water and oil systems.The mechanism and elementary reaction of RCMP were explored deeply,revealing that the complexation of initiator with DES to generate radicals was a ratecontrolling step and intermolecular-hydrogen-bond was primary factor to influence polymerization rate.Moreover,the insights of density functional theory calculations revealed that negative electrostatic potential ensured nucleophilic capacity.This investigation demonstrated the considerable potential of DES for RCMP,which is anticipated for other polymerization applications as a novel medium mode.
文摘A mathematical model has been developed to handle the reactions in Poly(ethylene terephthalate) (PET) undergoing polycondensation reactions in the solid state. The effect of temperature on chain mobility was considered to estimate the rate constants of chemical reactions. The polymer crystalline fraction is modeled as containing only repeat units, thus concentrating end groups and conden-sates in the amorphous fraction. This model is compared with PET reaction data with good results.
基金This work was supported by the National Natural Science Foundation of China (No. 20474028)Jiangsu Provincial Natural Science Foundation (No. BK2004086).
文摘Chiral polymer was synthesized by the polymerization of （R）-6,6＇-bistributylstannyl-2,2＇-binaphtho-20-crown-6 （M-1） with 1,4-dibromo-2,3-bisbutoxy-naphthyl （M-2） by Pd（PPhs）4 catalyzed Stille coupling reaction. Both monomer and polymer were analyzed by NMR, MS, FT-IR, UV, polarimetry, DSC-TGA, CD, fluorescent spectroscopy and GPC. The major difference between monomer and polymer is that a long wavelength Cotton Effect was observed for the polymer due to its more extended conjugation in the repeating unit and a highly rigid backbone in the polymer chain. Polymer has strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the repeating unit of the polymer to the chiral binaphthyl core and is expected to have potential application in the materials of fluorescent sensors and chiral chromatographic packing for resolution ofracemic amino acid.
基金The authors are grateful to financial support from the National Natural Science Foundation of China，the East China University of Science and Technology
文摘A new conjugated copolymer （PTST-DyOXD） derived from 1,1-dimethyl-3,4-diphenyl-2,5-bis（5-bromo-2- thienyl）-silole （TST） and 2,5-bis（4-ethynylphenyl）-l,3,4-oxadiazole （DyOXD） was synthesized by Pd（0）-catalyzed Sonogashira coupling reaction. For comparison, another copolymer without acetenyl group （PTST-OXD） was also synthesized by Pd（0）-catalyzed Suzuki coupling reaction. Chemical structures and optoelectronic properties of the copolymers were characterized by IH NMR, 13C NMR, IR, UV-vis absorption, photoluminescence and cyclic voltammetry. The number-average molecular weight （Mn） is 4010 Da for PTST-DyOXD and 3890 Da for PTST-OXD, respectively. The thermogravimetric analysis （TGA） measurements show that they have good thermal stability with decomposition temperature at 312 and 318 ~C, respectively. The optical band gap is 2.21 eV for PTST-DyOXD and 2.10 eV for PTST-OXD based on the absorption onset. CV analysis revealed the LUMO level of PTST-DyOXD is -3.04 eV, lower than that of PTST-OXD （about -2.89 eV）, which is attributed to the introduction of acetylene group in PTST-DyOXD, increasing the system of the conjugate chain length.
