Co-reporter:Cao Zhou, Tongqing Xie, Rui Zhou, Carl O. Trindle, Yavuz Tikman, Xingyuan Zhang, and Guoqing Zhang
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 31) pp:17209
Publication Date(Web):July 20, 2015
DOI:10.1021/acsami.5b04075
Single-component materials with both fluorescence and room-temperature phosphorescence (RTP) are useful for ratiometric sensing and imaging applications. On the basis of a general design principle, an amino-substituted benzophenone is covalently incorporated into waterborne polyurethanes (WPU) and results in fluorescence and RTP single-component dual-emissive materials (SDMs). At different aminobenzophenone concentrations, the statistical, thermal, and optical properties of these SDMs are characterized. Despite their similar thermal behaviors, the luminescence properties as a function of the chromophore concentration are quite different: increasing concentrations led to progressively narrowed singlet–triplet energy gaps. The tunability of fluorescence and RTP via chromophore concentration is explained by a previously proposed model, polymerization-enhanced intersystem crossing (PEX). The proposal of PEX is based on Kasha’s molecular exciton theory with a specific application in polymeric systems, where the polymerization of luminophores results in excitonic coupling and enhanced forward and reverse intersystem crossing. The mechanism of PEX is also examined by theoretical calculations for the WPU system. It is found that the presence of K1 aggregates indeed enhances the crossover from singlet excited states to triplet ones.Keywords: dual-emissive; fluorescence; room-temperature phosphorescence; single-component; waterborne polyurethane
Co-reporter:Akram Yasin;Wanfu Zhou;Haiyang Yang;Huazhen Li;Yin Chen;Xingyuan Zhang
Macromolecular Rapid Communications 2015 Volume 36( Issue 9) pp:845-851
Publication Date(Web):
DOI:10.1002/marc.201400698
Co-reporter:Junpei Li, Xingyuan Zhang, Zheng Liu, Weihu Li, Jiabing Dai
Journal of Fluorine Chemistry 2015 Volume 175() pp:12-17
Publication Date(Web):July 2015
DOI:10.1016/j.jfluchem.2015.02.015
•WPU with fluorinated medium branched chain were synthesized.•Water/solvent resistance, thermal and mechanical properties of WPU were improved.•Effect of physical properties on WPU with fluorine content was well studied.•This study opens a window to produce high-performance polyurethane materials.A novel fluorinated diol 3-(bis-(N,N-dihydroxyethyl)) dodecafluoroheptyl acrylate (DEFA) was for the first time synthesized via Michael addition reaction between diethanolamine and dodecafluoroheptyl acrylate, followed by a series of waterborne fluorinated polyurethane emulsions IPDI-DEFA-PU synthesis using isophorone diisocyanate (IPDI), poly(tetramethylene oxide glycol) (PTMG), dimethylolpropionic acid (DMPA) and 1,4-butanediol (BDO) as main starting materials, and DEFA as a chain extender. The structure of DEFA and IPDI-DEFA-PU was confirmed by Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (1H NMR). It was found that the fluorine content increased from 0 to 15.1%, and the particle size of emulsion increased from 102 nm to 260 nm, whereas the surface tension of latex film decreased from 42.9 mN/m to 16.5 mN/m; while the water contact angle increased from 71° to 104°, the swelling ratio of latex film in water and cyclohexane decreased from 15.8% to 1.1% and from 28.8% to 3.4%, respectively. Meanwhile, water/organic solvent resistance and thermal stability, mechanical properties of IPDI-DEFA-PU were all improved. As tensile strength increased from 9 MPa to 15 MPa, extensibility decreased from 520% to 280%.The water/organic solvent resistance, thermal stability and mechanical properties of the resulting fluorinated waterborne polyurethanes were all improved. It was found that the fluorine content increased from 0 to 15.1%, and the tensile strengths increased from 9 MPa to 15 MPa, whereas the extensibility decreased from 520% to 280%.
Co-reporter:Junpei Li;Xingyuan Zhang;James Gooch;Wei Sun;Huaiwei Wang
Polymer Bulletin 2015 Volume 72( Issue 4) pp:881-895
Publication Date(Web):2015 April
DOI:10.1007/s00289-015-1312-9
In this study, a novel photo- and pH-sensitive cationic waterborne polyurethane containing side chain aromatic azo groups (Azo-CWPU) was synthesized by step-growth addition polymerization from polyether polylol, isophorone diisocyanate, N-methyl diethanolamine and a new aromatic azo-containing monomer, 2,2′-(4-((4-ethylphenyl)diazenyl)phenylazanediyl)diethanol (EDPD). Azo-CWPU showed a significant hypsochromic contrast to the azo monomer and rapid changes in UV–Vis absorption spectra at different irradiation times. Azo-CWPU dispersion displays bright yellow, orange and red color with the change of pH values. Regarding the orange dispersion, we assume that there is a mixture of the azoic form and the hydrazone form. Compared to cationic waterborne polyurethane dispersion without aromatic azo groups (CWPU), Azo-CWPU dispersion with smaller hydrodynamics radius and more narrow distribution shows good thermodynamic properties of polyurethane.
Co-reporter:Xianhai Hu;Xingyuan Zhang;Jin Liu;Jiabing Dai
Polymer International 2014 Volume 63( Issue 3) pp:453-458
Publication Date(Web):
DOI:10.1002/pi.4523
Abstract
A waterborne-polyurethane-based fluorescent dye 4-amino-N-cyclohexyl-1,8-naphthalimide (WPU-ACN) was synthesized by attaching 4-amino-N-cyclohexyl-1,8-naphthalimide (ACN) into polyurethane chains according to a prepolymer−ionomer process. The structure of WPU-ACN was confirmed by means of Fourier transform infrared spectroscopy and UV−visible absorption. The number-average molecular weight, glass transition temperature and average emulsion particle size for WPU-ACN were determined as 7.8 × 105 g mol−1, 60 °C and 60 nm, respectively. The improved thermal stability of WPU-ACN could be attributed to the incorporation of naphthalimide units in the preformed urethane groups. The fluorescence intensity of WPU-ACN was dramatically enhanced compared with that of ACN. It was found that the fluorescence intensity of WPU-ACN increased with increasing temperature, and the fluorescence spectra of WPU-ACN showed a positive solvatochromic effect. In addition, the fluorescence of WPU-ACN emulsion was very stable not only for long-term storage but also for fluorescence quenching. © 2013 Society of Chemical Industry
Co-reporter:Long Zhang;Xingyuan Zhang;Lijun Wu;Yipeng Deng ;Ruijie Liu
Polymer International 2014 Volume 63( Issue 9) pp:1650-1657
Publication Date(Web):
DOI:10.1002/pi.4684
Abstract
Isothermal and non-isothermal crystallization kinetics of long alkane chain segment nylon 1010, 1013 and 1014 were investigated by differential scanning calorimetry. The commonly used Avrami equation and that modified by Jeziorny were employed to fit the isothermal and non-isothermal crystallizations of nylon 1010, 1013 and 1014, respectively. It was found that the crystallization rate of nylon with a longer alkane chain segment was slower than that of nylon with a shorter one at a given cooling rate. The activation energies for the isothermal and non-isothermal crystallizations determined by the Arrhenius and the Kissinger methods, respectively, decreased with increase of the alkane chain segment length of nylon 1010, 1013 and 1014. Furthermore, the activation energy of the non-isothermal crystallization process of these nylons, determined by the isoconversional methods of Flynn and Wall and Ozawa, was found to be a decreasing function of the relative degree of crystallinity. © 2014 Society of Chemical Industry
Co-reporter:Hu Xianhai, Xingyuan Zhang, Jin Liu, Jiabing Dai
Journal of Luminescence 2013 Volume 142() pp:23-27
Publication Date(Web):October 2013
DOI:10.1016/j.jlumin.2013.02.048
A novel anionic waterborne polyurethane-based fluorescent dye WPU-DV26 was synthesized by incorporating the molecular structure of disperse violet 26 (DV26) into the polyurethane chain. The structure of WPU-DV26 was confirmed by means of Fourier transform infrared spectroscopy and UV–vis absorption analysis. Comparing to the UV–vis spectrum of DV26, WPU-DV26 showed a hypsochromic shift from the absorption maxima of 518, 558, 609 nm to 510, 548, 586 nm, respectively. WPU-DV26 can form stable latex in water. The number average molecular weight and its distribution index, and average latex particle size for WPU-DV26 were determined to be 2.33×104, 1.36 and 80 nm, respectively. The improved thermal stability of WPU-DV26 can be attributed to the embedded anthraquinone unit of DV26. It was found that both the intensity and stability of the fluorescence of WPU-DV26 latex were improved significantly compared with those of DV26.Highlights► A waterborne polyurethane-based polymeric dye was synthesized. ► The fluorescence intensity of WPU-DV26 emulsion was enhanced greatly compared with that of DV26. ► The fluorescence stability of WPU-DV26 emulsion was fine not only for long term storage but also for fluorescence quencher.
Co-reporter:Xi Wang;Xingyuan Zhang;Long Zhang
Journal of Applied Polymer Science 2013 Volume 128( Issue 1) pp:400-406
Publication Date(Web):
DOI:10.1002/app.38160
Abstract
Nonisothermal crystallization behavior of poly(butylene terephthalate) (PBT) was investigated by means of differential scanning calorimetry. The nonisothermal crystallization kinetic process was analyzed and relative kinetic parameters were obtained with the Avrami and Liu–Mo equations. The results demonstrate a heterogeneous nucleation mechanism. It was found that the nonisothermal primary crystallization of PBT was composed of two courses. Course I corresponded to the two-dimensional formation process of the lamellae, and the corresponding relative crystallinity (Xt) was less than 15%. Course II was concerned with the three-dimensional growth process of the spherulite, and Xt changed from 15 to 90%. The secondary crystallization began when Xt was greater than 90%. According to the Flynn–Wall–Ozawa equation, the activation energies for course I, course II, and secondary crystallization were calculated to be −120, −210, and −100 kJ/mol, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Co-reporter:Pei Xu;Jin Zhu;Xingyuan Zhang
Polymer Bulletin 2013 Volume 70( Issue 11) pp:3091-3102
Publication Date(Web):2013 November
DOI:10.1007/s00289-013-1009-x
Poly[methyl methacrylate(81)/butyl acrylate(19)] copolymer was exposed to atmosphere of humidity for various times. The normal α and ρ peak, a third LL peak is observed in thermally stimulated depolarization current (TSDC) spectra of the copolymer. The α peak corresponds to the glass transition, the ρ peak originates from the detrapping of trapped carriers in the bulk amorphous structure, and the LL peak can be attributed to the charge detrapping related to the liquid–liquid transition of the copolymer. The three peaks all move to lower temperature with an increase of the moisture content, indicating that the flexible moisture content not only has an effect of plasticization on the glass transition and liquid–liquid transition, but also makes the trap depth of ρ peak shallower. The trap depth of ρ peak is affected by the introduction of moisture content and the degree of hydration of the copolymer. Based on analysis of calculated results, it was confirmed that the relaxation time of LL peak obeys VF equation when temperature is below TLL.
Co-reporter:Xian Hai Hu, Xing Yuan Zhang, Jia Bing Dai
Chinese Chemical Letters 2012 Volume 23(Issue 7) pp:855-858
Publication Date(Web):July 2012
DOI:10.1016/j.cclet.2012.05.020
A novel fluorescent aqueous polyurethane emulsion DDAQ-TDI-PU was synthesized by blocking the anthraquinone moiety of 1,4-diamino-2,3-diphenoxyanthraquinone (DDAQ) into polyurethane chain using 2,4-tolylene diisocyanate (TDI), poly(propylene glycol) and 2,2-dimethylol propionic acid. The chain structure of DDAQ-TDI-PU was confirmed by means of Fourier transform infrared spectroscopy and UV–vis analysis. Comparing to the UV–vis spectrum of DDAQ, DDAQ-TDI-PU showed a hypsochromic shift from the absorption maxima of 518, 558, 609 nm to 510, 548, 586 nm, respectively. It was found that the fluorescence intensity of DDAQ-TDI-PU emulsion was enhanced greatly comparing with that of DDAQ. The fluorescence of DDAQ-TDI-PU was very stable not only for the long term storage but also for the fluorescence quencher.
Co-reporter:Pei Xu ;Xingyuan Zhang
Journal of Applied Polymer Science 2012 Volume 124( Issue 6) pp:4486-4490
Publication Date(Web):
DOI:10.1002/app.35461
Abstract
The chain segment motion and charge detrapping in polyamide 610 films have been investigated by means of thermally stimulated depolarization current (TSDC) and wide-angle X-ray diffraction. There are three current peaks (namely α, ρ1, and ρ2 peaks) in the TSDC spectra above room temperature. α peak is attributed to a dipole relaxation by the motion of chain segments ρ1 peak is caused by space charge trapped in amorphous phase and the interphase between crystalline and amorphous phases, and ρ2 peak is brought about by space charge trapped in crystalline phase. By analyzing the characteristic parameters of these peaks, it is found that annealing induces the decrease of chain segment mobility and promotes the creation of structural traps in polyamide 610. The decrease of chain segment mobility in amorphous phase makes intensity of α peak weak and activation energy increscent. The higher the annealing temperature, the higher the degree of crystallinity, the more the charge carriers trapped in crystalline phase. So, the increase of degree of crystallinity makes intensity of ρ2 peak strong and increases the stability of trapped charge in the crystalline phase. The increase of annealing temperature makes intensity of ρ1 peak strong and decreases the stability of trapped charge in the amorphous phase and interphase. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Co-reporter:Lunlun Gong;Xingyuan Zhang;Yuan Shi;Long Zhang
Polymer Bulletin 2012 Volume 68( Issue 3) pp:847-857
Publication Date(Web):2012 February
DOI:10.1007/s00289-011-0657-y
Thermally stimulated depolarization current (TSDC) experiments were carried out to investigate the effect of polarization temperature (Tp) on liquid–liquid transition and space charge detrapping behavior in atactic polystyrene. Differential scanning calorimetry (DSC) measurement was applied as a complementary method. When Tp is 130 °C, there are four distinct peaks (α, ρ1, LL, and ρ2) showed in TSDC spectrum in the range of 30–200 °C. Compared with the result of DSC, TSDC spectrum show that peak α corresponds to glass transition, peak LL is related to liquid–liquid transition, and peak ρ1 and peak ρ2 belong to the space charge current peak. As Tp increases from 100 to 150 °C, the intensity of peak LL maximum increases and that of space charge peaks maxima decreases, which is attributed to different mechanism between liquid–liquid transition and space charge detrapping behavior. In addition, their corresponding characteristic parameters versus Tp are also analyzed in detail.
Co-reporter:Zhi Li;Xingyuan Zhang;Jiabing Dai;Rui Shi;Fei Xu
Colloid and Polymer Science 2012 Volume 290( Issue 5) pp:457-464
Publication Date(Web):2012 March
DOI:10.1007/s00396-011-2566-x
A series of poly(3-methacryloxypropyltrimethoxysilane)/waterborne polyurethane (PMPS/WPU) composite latexes and organic–inorganic hybrid films with PMPS contents of 0, 10, 20, 30, 40 and 50 wt.% were prepared via seeded emulsion polymerization initiated by AIBN and hydrolysis–condensation process of PMPS during the evaporation of water, respectively. WPU, that is anionic polyurethane emulsion, was synthesized using isophorone diisocyanate, polytetramethylene ether glycol, dimethylol propionic acid, 1,4-butanediol, and triethylamine. An investigation of transmission electron microscopy confirmed the core–shell morphology of the composite latex particle which was composed of a PMPS core and a polyurethane shell. A dynamic light scattering analysis showed that the average particle size distributed in the range of 42–134 nm. The proposed novel preparation method included the use of polyurethane as macromolecular emulsifier and steric stabilizer, control of (3-methacryloxypropyltrimethoxysilane) (MPS) content less than 50 wt.%, slow addition of MPS and application of AIBN ensured the preparation of a stable PMPS/WPU composite latex. Formed PMPS/WPU organic–inorganic hybrid film with high PMPS content via sol-gel process had uniform transparency at visible band because of less crystalline and phase separation between organic and inorganic phases.
Co-reporter:Pei Xu, Xingyuan Zhang
European Polymer Journal 2011 Volume 47(Issue 5) pp:1031-1038
Publication Date(Web):May 2011
DOI:10.1016/j.eurpolymj.2011.02.016
Dielectric relaxation spectroscopy technique was employed to study the Maxwell–Wagner–Sillars (MWS) polarization and dc conductivity in polyamide 610. The experimental dielectric data were analyzed within the formalisms of complex permittivity and electric modulus. The results were discussed in terms of ac conductivity, MWS polarization, electrode polarization and dc conductivity. In the frequency spectra of polyamide 610, charge carriers movement resulted in high values of the dielectric permittivity. The results revealed that the motion of the polymer chains governs the charge carrier transport. Two different mechanisms for charge carrier movement showed a transition temperature located between 110 and 120 °C. The change of charge carrier movement mechanisms was resulted from the onset of the polymeric chains in the interphase between amorphous and crystalline phases.Correlation of τMWS with temperature for MWS polarization. The line represents the fitting equation.
Co-reporter:Lunlun Gong, Xingyuan Zhang, Yuan Shi
European Polymer Journal 2011 Volume 47(Issue 10) pp:1931-1935
Publication Date(Web):October 2011
DOI:10.1016/j.eurpolymj.2011.07.004
Thermally stimulated depolarization current (TSDC) measurement was used to investigate the liquid–liquid transition process of atactic polystyrene (aPS). There are four distinct peaks (α, ρ1, LL and ρ2) showed in TSDC spectrum in the range of 300–480 K. Compared with the result of differential scanning calorimetry for aPS, the TSDC spectrum showed that the peak LL located at 422 K could be attributed to the movement of entire chain related to liquid–liquid transition. The isolated peak LL was separated from TSDC spectrum of aPS by curve fitting procedure of the kinetics equation. The distribution of relaxation time of liquid–liquid transition was obtained in terms of the principle of Debye relaxation process. Based on analysis of calculated results, it was confirmed that the relaxation time during the liquid–liquid transition of aPS changed gradually from following Vogel–Fulcher equation to Arrhenius rule with increasing temperature.Graphical abstractA plot of lnτ as a function of 1000/T (solid line) for the liquid–liquid transition of aPS is shown below.Highlights► The liquid-liquid transition of atactic polystyrene is investigated by means of TSDC. ► Relaxation time follows Vogel-Fulcher equation below liquid-liquid transition temperature. ► Relaxation time accords with Arrhenius equation above liquid-liquid transition temperature. ► Movement of molecular chain changes from restricted to free with increasing temperature.
Co-reporter:Xian-Hai Hu, Xing-Yuan Zhang, Jia-Bin Dai, Jin Liu
Journal of Luminescence 2011 Volume 131(Issue 10) pp:2160-2165
Publication Date(Web):October 2011
DOI:10.1016/j.jlumin.2011.05.026
Fluorescent brightening agent VBL-based waterborne polyurethane dye (VBL–WPU) was synthesized by incorporation of VBL into waterborne polyurethane chains. The expected structure of polymeric fluorescent brightening agent was confirmed by FT-IR and UV–vis spectra. The molecular weight, average particle sizes and the contents of VBL segments in VBL–WPU were investigated. This polymeric dye exhibited intriguing optical behaviors. The absorption and emission maxima of VBL–WPU showed obviously hypsochromic shift in comparison with those of VBL. The fluorescence intensity of the polymer was prominently enhanced comparing with VBL because of the changes of micro-circumstance of VBL. Furthermore, the fluorescence of VBL–WPU was not sensitive to hydroquinone quencher.Highlights►A fluorescent brightener VBL-based waterborne polyurethane dye is synthesized. ► Absorption and emission maxima of the dye are blue shift about 16 and 11 nm. ► Fluorescence intensity of the dye is prominently enhanced comparing with VBL. ► Fluorescence of the dye is stable and is not sensitive to hydroquinone quencher.
Co-reporter:Xian Hai Hu, Xing Yuan Zhang, Jia Bin Dai
Chinese Chemical Letters 2011 Volume 22(Issue 8) pp:997-1000
Publication Date(Web):August 2011
DOI:10.1016/j.cclet.2011.01.028
A novel waterborne stilbene-based polyurethane fluorescent brightener dispersion WPU-VBL was synthesized by incorporating chemically disodium 4,4′-bis[(4-anilino-6-hydroxyethylamino-1,3,5-triazin-2-yl)amino]stilbene-2,2′-disulphonate (VBL) into the polyurethane chain using isophorone diisocyanate, poly(propylene glycol) and 2,2-dimethylol propionic acid. The structure of WPU-VBL was confirmed by means of Fourier transform infrared spectroscopy. The UV–vis absorption analysis showed a hypsochromic shift of 16 nm when VBL was blocked into polyurethane chain. Number average molecular weight of 2.1 × 104, molecular weight distribution of 2.1 and average latex particle size of about 70 nm for WPU-VBL were determined based on the analysis of gel permeation chromatography and laser particle size analyzer. It was found that the fluorescence intensity of WPU-VBL was prominently enhanced because of the micro-circumstance of VBL and the fluorescence of WPU-VBL was very stable.
Co-reporter:Jie Zhang, Xing Yuan Zhang, Jia Bing Dai, Wei Hu Li
Chinese Chemical Letters 2010 Volume 21(Issue 2) pp:143-145
Publication Date(Web):February 2010
DOI:10.1016/j.cclet.2009.10.018
A novel and facile method toward a series of yellow water-borne polyurethane was developed by using an intrinsically colored diol in this paper. The yellow aqueous dispersion PCLD–HENA–PU was synthesized based on isophorone diisocyanate (IPDI), polycaprolactonediol (PCLD) and 2,2-dimethylol propionic acid (DMPA) using a yellow diol N,N-bis(2-hydroxyethyl)-4-nitroaniline (HENA) as a chain extender. Due to the complete reaction of OH group in colorant HENA with NCO group in diisocyanate, a series of stable yellow polyurethanes could be obtained conveniently and easily. The structure of PCLD–HENA–PUs was confirmed by means of Fourier transform infrared spectroscopy. The UV–visible absorption analysis showed a blue shift effect of about 7 nm when HENA was blocked into polyurethane chain. The absorption intensity of PCLD–HENA–PUs increased with increasing HENA content. It was found that the tensile strength enhanced from 8.6 to 19.6 MPa with HENA content increased from 0 to 18.0%, while the extensibility decreased from 449 to 300%. The thermal gravimetric analysis presented that the initial decompose temperature began from about 250 °C, and had a little increase with increasing the HENA content.
Co-reporter:Zhen Ge, Xingyuan Zhang, Jiabing Dai, Weihu Li, Yunjun Luo
European Polymer Journal 2009 Volume 45(Issue 2) pp:530-536
Publication Date(Web):February 2009
DOI:10.1016/j.eurpolymj.2008.11.008
A novel fluorinated polyurethane (FPU) was prepared by fluorinated polyether glycol (PTMG-g-HFP) as a soft segment, 1,6-hexamethylene diisocyanate (HDI) or toluene diisocyanate (TDI) as a hard segment and 1,4-butanodiol (BDO) as a chain extender. Fourier transform infrared spectroscopy (FTIR), 1H NMR, 13C NMR and gel permeation chromatography (GPC) were used to characterize the structure of the fluorinated polyurethane. The thermal stabilities of the fluorinated polyurethane and the corresponding hydrogenated polyurethane were studied by thermogravimetric analysis (TGA). X-ray photoelectron spectroscopy (XPS) analysis at two different sampling depths for the fluorinated polyurethane was used to investigate the surface compositions of FPU. And the mechanical properties of the fluorinated polyurethane and the corresponding hydrogenated polyurethane were also measured. Chemical resistance of polyurethane films was estimated through spot tests with different solvents. The results showed that FPU had high thermal stability, strain-hardening property and good chemical resistance. The XPS measurements showed the fluorine enrichment on the surface of FPU.
Co-reporter:Wei Hu Li, Xing Yuan Zhang, Jia Bing Dai
Chinese Chemical Letters 2009 Volume 20(Issue 9) pp:1127-1130
Publication Date(Web):September 2009
DOI:10.1016/j.cclet.2009.03.012
Fluorinated poly(ethylene oxide) propyl-b-polydimethylsiloxane-b-propyl fluorinated poly(ethylene oxide) (FPEO-b-PDMS-b-FPEO) was synthesized by a free radical addition of carbon–hydrogen of polyether segments of poly(ethylene oxide) propyl-b-polydimethylsiloxane-b-propyl poly(ethylene oxide) (PEO-b-PDMS-b-PEO) to hexafluoropropylene (HFP) using tert-butyl peroxypivalate as an initiator. In order to reduce the possibility of side reaction, the protection and deprotection via silylation were used for the end-hydroxyls in PEO-b-PDMS-b-PEO chain. The structure of Intermediates and FPEO-b-PDMS-b-FPEO was confirmed by means of Fourier transform infrared and 1H NMR spectroscopy. The effects of amount of initiator, reaction temperature and time on free radical addition were investigated in detail.
Co-reporter:Chuyin Zhang, Xingyuan Zhang, Jiabing Dai, Chenyan Bai
Progress in Organic Coatings 2008 Volume 63(Issue 2) pp:238-244
Publication Date(Web):September 2008
DOI:10.1016/j.porgcoat.2008.05.011
A new type of polysiloxane modified polyurethane–acrylic hybrid emulsion was synthesized by solvent-free method and the polysiloxane was introduced into the soft segment of polyurethane chains using dihydroxybutyl-terminated polydimethylsiloxane (PDMS). The formed film from the hybrid emulsion could provide obviously higher water-resistance property. The preparation technologies such as the content of carboxy group and acrylic monomer, the rate and the time of emulsification were discussed systematically. The chain structure and the particle size were confirmed by the analysis of Fourier transform infrared spectroscopy and transmission electron microscopy, respectively. The effect of PDMS content on the water resistance and the mechanical property were investigated by absorbed water ratio, water contact angle and dynamic mechanical measurement.
Co-reporter:Chenyan Bai;Xingyuan Zhang;Jiabing Dai
Journal of Polymer Research 2008 Volume 15( Issue 1) pp:67-73
Publication Date(Web):2008 February
DOI:10.1007/s10965-007-9144-4
Two types of UV curable waterborne blocked polyurethanes (PUs) were obtained from 2,4-tolylene diisocyanate(TDI) and isophorone diisocyanate (IPDI), which had the same soft segments and different hard segments. The PUs contained both the UV curable C=C bond and the blocked NCO groups which could be de-blocked when heated. Effect of the hard segment on the properties of the two types of PUs was investigated. The FTIR spectra method was employed to confirm the structure of the PUs. The photo-DSC was used to study the photo-polymerization rate of the PUs under UV irradiation in the presence of a photo-initiator and the C=C conversion behaviors. Heating-up IR analysis was used to track the de-blocking process and the heat curing process. The thermal degradation analysis (TGA) was employed to investigate the thermal stability of the UV cured films before and after heat curing process. Dynamic mechanical properties of the UV and heat cured films were investigated by the dynamic mechanical thermal analysis (DMTA).
Co-reporter:Linlin Feng;Xingyuan Zhang;Jiabing Dai;Zhen Ge
Frontiers of Chemistry in China 2008 Volume 3( Issue 1) pp:1-5
Publication Date(Web):2008 January
DOI:10.1007/s11458-008-0001-8
A series of polyurethanes modified by polysiloxane (Si-PU) were synthesized based on 2,4-toluene diisocyanate (TDI), dihydroxybutyl-terminated polydimethylsiloxane (DHPDMS), polytetramethylene glycol (PTMG) and 1,4-butanediol (BDO). Fourier transform infrared spectroscopy analysis showed that DHPDMS had been incorporated into the polyurethane chains. With the increase of DHPDMS content, the water contact angle increased while the surface tension decreased. As the DHPDMS content increases above 5%, both the contact angle and the surface tension tend to approach a constant. The contact angle increases with increasing temperature, and it tends to approach a constant when the temperature is higher than 50°C. The result indicates that Si-PU exhibits good surface and mechanical properties when the DHPDMS content is 5%.
Co-reporter:Chenyan Bai;Xingyuan Zhang;Jiabing Dai
Journal of Coatings Technology and Research 2008 Volume 5( Issue 2) pp:251-257
Publication Date(Web):2008 June
DOI:10.1007/s11998-007-9062-8
A UV crosslinkable waterborne siloxane–polyurethane dispersion, PDMS-PEDA-PU, was synthesized by incorporating acrylate groups into the side chain of the polyurethane using pentaerythritol diacrylate (PEDA). Polysiloxane groups were introduced into the soft segment of the polyurethane using polydimethylsiloxane (PDMS). They formed a crosslinking structure after UV radiation. The structure of PDMS-PEDA-PU was confirmed by the use of Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) analysis indicated that the formed PDMS-PEDA-PU was amorphous. The curing rule of PDMS-PEDA-PU was investigated on the basis of the change in C=C conversion during the UV curing process. The influence of the PDMS/PEDA ratio was studied with respect to the water resistance, the thermal property, and the mechanical property of the films.
Co-reporter:Chen Yan Bai, Xing Yuan Zhang, Jia Bing Dai, Chu Yin Zhang
Progress in Organic Coatings 2007 Volume 59(Issue 4) pp:331-336
Publication Date(Web):2 July 2007
DOI:10.1016/j.porgcoat.2007.05.003
The water absorption of the membranes made from UV curable waterborne polyurethane dispersions (UV-PUDs) was investigated systematically and correlated with the nature of the polymer and its gel content after curing. It was found that the water absorption of the membranes was reduced significantly by using polyester polyols, reducing the COOH content and increasing the gel content through a higher CC level. In particular, the membranes made from polyurethanes having hydroxyl-terminated polybutadiene (HTPB) or modified with dihydroxybutyl-terminated polydimethylsiloxane (PDMS) presented a superior water resistance. The results showed a linear relationship between the water absorption and the surface tension of the membrane.
Co-reporter:Xingyuan Zhang;Jing Chao;Jiabing Dai;Zhen Ge;Weihu Li;Linlin Feng;Zhen Ge;Xingyuan Zhang;Jiabing Dai;Weihu Li;Jing Chao;Linlin Feng
Journal of Applied Polymer Science 2007 Volume 104(Issue 2) pp:1138-1142
Publication Date(Web):26 JAN 2007
DOI:10.1002/app.25743
The acetylation reaction of polytetramethylene glycol (PTMG) with acetic anhydride in pyridine was studied. The extent of acetylation was measured by 1H-NMR, and the acetylation product was characterized with FTIR, 1H-NMR, and 13C-NMR. The effects of the experimental conditions, i.e., reaction time and temperature, acetylation reagent concentration (anhydride and hydroxyl molar ratio), were investigated. The increase in reaction temperature and reaction time favored the acetylation yields. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1138–1142, 2007
Co-reporter:Jia Bing Dai;Jing Chao
Journal of Coatings Technology and Research 2007 Volume 4( Issue 3) pp:283-288
Publication Date(Web):2007 September
DOI:10.1007/s11998-007-9042-z
A novel core–shell type fluorinated acrylic and siliconated polyurethane (FSiPUA) hybrid emulsion was prepared by seeded emulsion polymerization using siliconated polyurethane (SiPU) as a seed and forming the structure with SiPU as a shell and the copolymer of butyl acrylate (BA) with 2,2,2-trifluoroethylmethacrylate (TFEMA) as a core. SiPU was synthesized using isophorone diisocyanate (IPDI), polytetramethylene ether glycol (PTMG), polypropylene glycol (PPG), dihydroxybutyl-terminated polydimethylsiloxane (PDMS), dimethylol propionic acid (DMPA), 1,6-hexanediol (HDO) and triethylamine (TEA). The contents of siloxane and fluorine were determined according to the feed ratio. Fourier transform infrared spectroscopy (FTIR) was used to identify the chain structure of SiPU and FSiPUA. Investigation of transmission electron microscopy (TEM) confirmed the core–shell structure of FSiPUA emulsion and gave the particle size at about 50 nm. The measurement results of water contact angles and the solvent absorptions in water and n-octane for cured films showed that the water and the oil repellency for FSiPUA had been improved significantly with a suitable content of fluorine and siloxane.
Co-reporter:Zhenbin Niu;Xingyuan Zhang;Jiabing Dai;Heping Zhang
Frontiers of Chemistry in China 2007 Volume 2( Issue 2) pp:151-155
Publication Date(Web):2007 April
DOI:10.1007/s11458-007-0031-7
A new kind of ultraviolet (UV) curable waterborne polyurethane acrylate dispersion was synthesized based on hydroxyl-terminated polybutadiene (HTPB), poly-(propylene glycol) (PPG), isophorene diisocyanate (IPDI), 2-hydroxy ethyl acrylate (HEA) and dimethylol propionic acid (DMPA) after neutralizing by triethylamine (TEA). 2-Hydroxy-1-[4-2-hydroxyethoxy) phenyl]-2-methyl-1-propanone (Irgacure 2959) was used as a photoinitiator and deionized water as a diluent. Fourier transform infrared (FTIR) analysis was used to identify the chain structure of the UV-curable polyurethane prepolymer based on HTPB and the curing process. Effects of relative content of HTPB and PPG on emulsion stability, resistance to water and ethanol, thermal stability, compatibility of soft and hard segment, as well as the mechanical property of the cured film were investigated.
Co-reporter:Chen Yan Bai, Xing Yuan Zhang, Jia Bing Dai, Wei Hu Li
Progress in Organic Coatings 2006 Volume 55(Issue 3) pp:291-295
Publication Date(Web):1 March 2006
DOI:10.1016/j.porgcoat.2005.12.002
A new ultraviolet (UV) curable waterborne polyurethane was prepared by modifying the conventional method of anionic aqueous polyurethane. Acrylate groups were introduced into the side chains and the end of the polyurethane main chains using the dihydric acrylate named as PEDA and the single-hydroxyl acrylate named as HEA. The CC content in the chain of the polyurethane was raised effectively and the maximum CC content achieved by this method is 4.5 meq/g. The structure was confirmed by the Fourier transform infrared spectroscopy (FTIR). The effects of different CC content were studied by evaluating various properties of the film such as the MEK resistance, hardness, thermal stability and the tensile properties. The curing rule of the polyurethane for different CC content had been investigated during the curing process.
Co-reporter:Hongbo Lu;Xingyuan Zhang;Bo He;Hui Zhang
Journal of Applied Polymer Science 2006 Volume 102(Issue 4) pp:3590-3596
Publication Date(Web):29 AUG 2006
DOI:10.1002/app.23987
Electrode polarization arising from charge carriers accumulating at the interface between an electrode and nylon 1010 was investigated with dielectric relaxation spectroscopy. In the frequency spectra of nylon 1010, the dielectric permittivity showed high values in the region of low frequencies and high temperatures. With the Havriliak–Negami function used to fit the experimental spectra, the result revealed that the high values originated from electrode polarization and direct-current conductivity. For electrode polarization, the dielectric strength, independent of the temperature, was about 1150, and the temperature dependence of the relaxation time followed the Vogel–Tammann–Fulcher equation. Fitting with the Vogel–Tammann–Fulcher equation, the parameters τ0 = 1.33 × 10−10 s and T0 = 303.2 K were proposed (where τ0 is the relaxation time at a very high temperature and T0 is the temperature at which the relaxation time becomes extremely large), and they suggested that the motion of the polymeric chains was one of the factors leading to charge-carrier transport at temperatures higher than the glass-transition temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3590–3596, 2006
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