YunSheng Ding

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Name: 丁运生

Organization: Hefei University of Technology , China

Department: Department of Polymer Materials and Engineering

Title: Professor(PhD)

Chemicals
References

A mechanically strong and tough anion exchange membrane engineered with non-covalent modalities

Co-reporter:Xiaojuan Wang;Ping Wang;Yiyan Sun;Jinlei Wang;Huagao Fang;Shanzhong Yang;Haibing Wei

Chemical Communications 2017 vol. 53(Issue 91) pp:12369-12372

Publication Date(Web):2017/11/14

DOI:10.1039/C7CC07284H

A mechanically robust and tough anion exchange membrane was constructed using the strategy of supramolecular modalities. After introducing a secondary amide as a hydrogen-bonding crosslinking motif into the side chain of the PPO backbone, the membrane exhibits high mechanical strength and excellent flexibility (101% elongation at break), as well as suppressed water uptake, enhanced thermal stability and good fuel cell performances.

Comb-shaped guanidinium functionalized poly(ether sulfone)s for anion exchange membranes: Effects of the spacer types and lengths

Co-reporter:

Journal of Polymer Science Part A: Polymer Chemistry 2017 Volume 55(Issue 8) pp:1313-1321

Publication Date(Web):2017/04/15

DOI:10.1002/pola.28496

ABSTRACTA series of poly(ether sulfone)-based anion exchange membranes (AEMs), tethering with guanidinium side chains with different spacers, were synthesized via azide-alkyne cycloaddition, deprotection, and the subsequent ion exchange reactions. The designed polymer structures were verified by the 1H NMR spectra. Because of the appropriate water uptake and formation of interconnected ionic clusters, the GPES-3C with propyl spacer showed higher conductivity than the GPES-1C and GPES-9C, with methylene and nonyl spacers, respectively. Comparatively, the GPES-EO AEM with two ethylene oxide (EO) spacers exhibited even higher conductivity, these can be interpreted by interconnectivity of ionic channels and hydrophilicity nature of the EO spacer. Additionally, although the GPES membranes displayed sufficient thermal stability, the chemical stability of as-prepared materials needs to be much improved for fuel cell applications. Overall, these results demonstrated that the properties of “pendent-type” AEM can be tuned facilely by the spacer types and lengths. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1313–1321

Enhanced cold crystallization and dielectric polarization of PLA composites induced by P[MPEGMA-IL] and graphene

Co-reporter:Pei Xu, Xiao Luo, Yiyang Zhou, Youwen Yang, Yunsheng Ding

Thermochimica Acta 2017 Volume 657(Volume 657) pp:

Publication Date(Web):10 November 2017

DOI:10.1016/j.tca.2017.10.005

•P[MPEGMA-IL] can improve the dispersion of Gra in PLA matrix.•P[MPEGMA-IL] and Gra can enhance the cold crystallization of composite.•Modified Gra can increase the mobile charge carriers at the interphase.•Modified Gra can increase the dielectric strength of interfacial polarization.To investigate the effect of modified graphene (Gra) by poly(methoxy poly(ethylene glycol) monomethacrylate-co-1-vinyl-3-ethylimidazolium bromide) (P[MPEGMA-IL]) on crystallization and dielectric behavior for poly(lactic acid) (PLA), the neat PLA and its composites were fabricated via solution blending and hot pressing. P[MPEGMA-IL] can improve the dispersibility of Gra in PLA matrix. The crystallization rate of PLA composites was increased with increasing the content of P[MPEGMA-IL] and Gra due to the plasticizing effect of P[MPEGMA-IL] and the nucleating effect of better-dispersed Gra. In the frequency spectra of PLA composites treated by cold crystallization process, α relaxation and interfacial polarization resulted in high values of dielectric permittivity. The incorporation of modified Gra into the matrix can accelerate interfacial polarization. The effect of modified Gra on charge carrier movement mechanism was resulted from the increase of the mobile charge carriers at the interphase and the dielectric strength of interfacial polarization.Download high-res image (213KB)Download full-size image

Enhanced dc conductivity and conductivity relaxation in PVDF/ionic liquid composites

Co-reporter:Pei Xu, Weijia Fu, Xiao Luo, Yunsheng Ding

Materials Letters 2017 Volume 206(Volume 206) pp:

Publication Date(Web):1 November 2017

DOI:10.1016/j.matlet.2017.06.104

•The interaction between ILs and >CF2 groups of PVDF can bring more polar phase for PVDF composites.•The incorporation of ILs into the matrix can accelerate dc conductivity.•The effect of IL on charge carrier movement mechanism was resulted from the increase of ion mobility.To investigate the effects of 1-benzyl-3-methylimidazolium hexafluorophosphate on the crystal phase, morphology and dielectric relaxation behavior of poly(vinylidene fluoride) (PVDF), a series of PVDF/IL composites have been prepared using solution-cast method. The interaction between ILs and >CF2 groups of PVDF can facilitate the PVDF chains in amorphous area to form more polar phase for PVDF composites. In the frequency spectra of PVDF composites, MWS interfacial polarization, electrode polarization and dc conductivity resulted in high values of dielectric permittivity. The incorporation of ILs into the matrix can accelerate dc conductivity. The effect of IL on charge carrier movement mechanism was resulted from the increase of ion mobility induced by polar phase crystal and ion concentration.

Synthesis and fluorescence properties of a waterborne polyurethane–acrylic hybrid polymeric dye

Co-reporter:Xianhai Hu;Jin Liu;Yao Deng;Congliang Cheng

Polymer Bulletin 2017 Volume 74( Issue 2) pp:555-569

Publication Date(Web):2017 February

DOI:10.1007/s00289-016-1729-9

A waterborne polyurethane–acrylic hybrid polymeric dye was prepared depending on soap-free emulsion polymerization method. The resulting polymeric dye composed of methyl methacrylate (MMA) monomer which was polymerized into polymethyl methacrylate (PMMA) as cores and waterborne polyurethane-based dye was synthesized by anchoring dye monomers (6-amino-2-cyclohexyl-benz[de]isoquinone-1,3-dione) to polyurethane chains as shells. The average particle sizes of the hybrid polymeric dye emulsions were found to be increased with the increase in MMA contents for MMA monomers. Compared with dye monomers, the absorption intensities and fluorescence intensities of the hybrid polymeric dye were enhanced with the increase of particle sizes. This study revealed that enhanced fluorescence intensity of the hybrid polymeric dye was mainly attributed to the hindered formation of exciplexes among dye monomers and an augmented light absorption area. It was found that the fluorescence intensity of the hybrid polymeric dye was increased with increasing temperature and the trend first increased and then decreased with increase in concentration. Furthermore, the fluorescence of the hybrid polymeric dye emulsions was found to be very stable and not sensitive to the fluorescence quencher.

Bis(2-oxoindolin-3-ylidene)-benzodifuran-dione and bithiophene-based conjugated polymers for high performance ambipolar organic thin-film transistors: the impact of substitution positions on bithiophene units

Co-reporter:Xiaohong Wang, Hyun Ho Choi, Guobing Zhang, Yunsheng Ding, Hongbo Lu, Kilwon Cho and Longzhen Qiu

Journal of Materials Chemistry A 2016 vol. 4(Issue 26) pp:6391-6400

Publication Date(Web):07 Jun 2016

DOI:10.1039/C6TC01617K

Three donor–acceptor polymers based on (3E,7E)-3,7-bis(2-oxoindolin-3-ylidene)benzo-[1,2-b:4,5-b]-difuran-2,6(3H,7H)-dione (BIBDF) and three kinds of dialkylated bithiophenes with head-to-head (HH), head-to-tail (HT), and tail-to-tail (TT) connectivity were synthesized by the Stille coupling reaction. Their photophysical and electrochemical properties, electronic device performance, and microstructure were investigated. We found that the alkyl chains substituted near the thiophene–thiophene connection cause less steric hindrance than those near the BIBDF–thiophene connection. Therefore PBIBDF-HH exhibited the preferred planarity, crystallinity, and molecular orientation, yielding the highest field-effect mobility. A maximum electron mobility of 1.23 cm2 V−1 s−1 and a maximum hole mobility of 0.37 cm2 V−1 s−1 were obtained for PBIBDF-HH-based devices. These results show that the substitution sites on the bithiophene units play an important role in the determination of molecular organization and the resulting device performance.

Tailoring elastomeric properties of waterborne polyurethane by incorporation of polymethyl methacrylate with nanostructural heterogeneity

Co-reporter:Huagao Fang, Haili Wang, Jing Sun, Haibing Wei and Yunsheng Ding

RSC Advances 2016 vol. 6(Issue 16) pp:13589-13599

Publication Date(Web):27 Jan 2016

DOI:10.1039/C5RA26664E

Although modification of waterborne polyurethane (WPU) using acrylic polymer (PA) is a widespread approach to prepare PU materials with high performance, not much attention has been paid to the variation of elastomeric property of the obtained WPUA hybrid materials with the presence of PA component. In this work, a series of aliphatic polycarbonate (PCDL) based waterborne polyurethane and polymethyl methacrylate (PMMA) hybrid dispersions (WPUA) were fabricated via a two-step procedure. The heterogeneous structure of hybrid dispersions was investigated, showing that the dispersed particles possess a nano-sized core–shell morphology. The hydrogen-bond interactions in hard domains are weakened by incorporation of PMMA component. The nanostructural heterogeneity in the dried films was determined by using MDSC, AFM, SAXS, DMA and linear rheology techniques. The tensile strength and strain-hardening modulus increase and the elongation at break decreases with increasing PMMA content. Plastic deformation of PMMA domains in WPUA only results in a loss in recoverable elasticity at low strains. With an optimized content of PMMA, the WPUA2 sample shows sharp yielding behavior while maintaining high extensibility and good recoverable elasticity at large strains. The improvement in elastomeric properties and other physical properties by incorporating PMMA component can expand the applications of waterborne PUs as environment-friendly thermoplastic elastomers.

Piezoresistive properties of nanocomposites based on silicone rubber and ionic liquid-functionalized carbon black

Co-reporter:Pei Xu, Xiaoxi Wang, Yadong Hu, Yunsheng Ding

Materials Letters 2016 Volume 182() pp:218-222

Publication Date(Web):1 November 2016

DOI:10.1016/j.matlet.2016.06.097

•IL can increase the conductivity of CB-IL/SR composites.•The CB-IL-5/SR composite has higher piezoresistivity and better repeatability.•The CB-IL-5/SR composite has shorter relaxation time.•Excellent piezoresistive behavior is due to the plasticizing effect of IL.High temperature vulcanized silicone rubber (SR) based nanocomposites with carbon black (CB) and ionic liquid-modified carbon black (CB-IL) as fillers were fabricated using mechanical mixing method and their piezoresistive properties were carefully characterized. 1-hexadecyl-3-methylimidazolium bromide (IL) can improve the dispersibility of CB in SR matrix by morphology characterization. The CB-IL/SR composites showed a lower percolation threshold compared with CB/SR composites. The CB-IL/SR composite with 5 vol% content of CB-IL shows higher piezoresistivity, better repeatability and shorter relaxation time due to the plasticizing effect of IL. The results suggest that the CB-IL/SR composites provide a new route toward fabrication of flexible piezoresistive sensors and wearable electronic devices.

Constructing pendent imidazolium-based poly(phenylene oxide)s for anion exchange membranes using a click reaction

Co-reporter:Jie Wang, Haibing Wei, Shanzhong Yang, Huagao Fang, Pei Xu and Yunsheng Ding

RSC Advances 2015 vol. 5(Issue 113) pp:93415-93422

Publication Date(Web):13 Oct 2015

DOI:10.1039/C5RA17748K

A series of poly(phenylene oxide)s (PPOs) bearing a flexible pendent imidazolium cation were prepared by an azide–alkyne cycloaddition between azidomethylated PPO and a novel alkyne-containing imidazolium, and their structures were confirmed by 1H NMR, 13C NMR, and FT-IR. The corresponding anion exchange membranes (AEMs) showed distinct hydrophobic/hydrophilic phase-separated morphology at higher imidazolium content, as evidenced by AFM and SAXS techniques, which favors for the construction of interconnected hydroxide transport channels. As a result, the as-prepared AEMs exhibited higher conductivity (95 mS cm−1, 80 °C, 100% RH) than conventional imidazolium benzylic-type AEM (55 mS cm−1, 80 °C, 100% RH) with even lower IEC. Furthermore, the introduction of a 1,2,3-triazole moiety into the polymer side chain does not compromise its thermal and alkaline stability. This investigation demonstrated that the “click chemistry” strategy will benefit further tailoring of high performance AEMs with “side-chain-type” architectures.

Synergistic effect of graphene and an ionic liquid containing phosphonium on the thermal stability and flame retardancy of polylactide

Co-reporter:Haoguan Gui, Pei Xu, Yadong Hu, Jie Wang, Xuefeng Yang, Ali Bahader and Yunsheng Ding

RSC Advances 2015 vol. 5(Issue 35) pp:27814-27822

Publication Date(Web):13 Mar 2015

DOI:10.1039/C4RA16393A

A series of nanocomposites based on the biodegradable plastic, polylactide (PLA), have been prepared by melt-blending with graphene (Gra) and ionic liquid containing phosphonium ([PCMIM]PF6, IL) surface-functionalized graphene (GIL). The morphology, mechanical properties, thermal stability and burning behaviour of the composites were investigated by Field Emission Scanning Electron Microscopy (FESEM), tensile test, impact test, Thermogravimetric Analysis (TGA), Limiting Oxygen Index (LOI), UL-94 test and Cone Calorimeter Test (CCT), respectively. The surface morphology and chemical structure of the char residues were explored by FESEM and Raman spectroscopy. It is confirmed that the fire-retardant performance of the PLA/GIL composites was significantly improved compared to PLA/IL and PLA/Gra; the CCT data showed a reduction in heat release rate and total heat released with increase of the char residue from the TGA results. It revealed that the catalytic charring effect of the ionic liquid, the physical isolating effect of graphene, and the combined effect of both the ionic liquid and graphene (forming continuous and compact char layers) were very efficient in improving the flame retarding properties of PLA/GIL nanocomposites.

Effect of graphene modified by a long alkyl chain ionic liquid on crystallization kinetics behavior of poly(vinylidene fluoride)

Co-reporter:Yadong Hu, Pei Xu, Haoguan Gui, Shanzhong Yang and Yunsheng Ding

RSC Advances 2015 vol. 5(Issue 112) pp:92418-92427

Publication Date(Web):08 Oct 2015

DOI:10.1039/C5RA17169E

To investigate the effects of graphene (Gra) modified by a long alkyl chain ionic liquid (1-hexadecyl-3-methylimidazolium bromide, IL) on the crystallization kinetics behavior of poly(vinylidene fluoride) (PVDF), a series of PVDF/IL blend, PVDF/Gra and PVDF/IL/Gra nanocomposites have been prepared using a solution-cast method. The crystallization kinetics and corresponding crystal structure have been investigated using differential scanning calorimetry (DSC), polarized optical microscopy (POM) and X-ray diffraction spectroscopy (XRD). The crystallization kinetic parameters, such as relative crystallinity (Xt), crystallization half time (t1/2), crystallization rate constant (Z), Avrami exponents (n) and activation energy (Ea), have been determined by both isothermal and non-isothermal techniques. In the isothermal and non-isothermal crystallization process, for PVDF/0.5IL/0.5Gra, IL and Gra can facilitate nucleation to decrease Ea; moreover, the synergistic efforts of IL and Gra can maintain appropriate crystallization rate to form the β phase extruded form the α phase. The positive effect on the crystallization of PVDF may be ascribed not only to the existence of Gra–cation interaction between the imidazolium cation and the aromatic carbon ring structure, but also to the electrostatic interaction between the CF2 group of the polymer backbone and imidazolium cation.

Synthesis of poly(ethylene glycol) functionalized star-shaped tricationic imidazolium based ionic liquid

Co-reporter:Di Zhang;Jun Yin 殷俊;Fei He;Ni-lin Ge;Zong-quan Wu

Chinese Journal of Polymer Science 2015 Volume 33( Issue 2) pp:245-255

Publication Date(Web):2015 February

DOI:10.1007/s10118-015-1576-4

We report on the preparation of a well-defined star-shaped tricationic ionic liquid possessing three arms of poly(ethylene glycol) functionalized imidazolium rings. Remarkable solubility was found in most of the organic solvents we used. Thermogravimetric analysis (TGA) exhibited excellent thermal stability and two distinct decomposition temperatures were attributed to two kinds of chemical degradation. Differential scanning calorimetry (DSC) was further employed to investigate the thermal phase transitions, that three different signals (Tg, Tc, and Tm) were shown upon the second heating process. Moreover, CH2Cl2 solution of the ionic liquid expressed an excitation-wavelength dependent fluorescence response, leading to the facile modulation of photoluminescence behavior. This work represents an example of utilizing molecular design to construct novel ionic liquids and endow further potential to be used in the engineering materials.

Crystallization kinetics of PVDF filled with multi wall carbon nanotubes modified by amphiphilic ionic liquid

Co-reporter:Ali Bahader;Haoguan Gui;Yu Li;Pei Xu

Macromolecular Research 2015 Volume 23( Issue 3) pp:273-283

Publication Date(Web):2015 March

DOI:10.1007/s13233-015-3039-8

Supertough Polylactide Materials Prepared through In Situ Reactive Blending with PEG-Based Diacrylate Monomer

Co-reporter:Huagao Fang, Feng Jiang, Qianghua Wu, Yunsheng Ding, and Zhigang Wang

ACS Applied Materials & Interfaces 2014 Volume 6(Issue 16) pp:13552

Publication Date(Web):August 8, 2014

DOI:10.1021/am502735q

Supertough biocompatible and biodegradable polylactide materials were fabricated by applying a novel and facile method involving reactive blending of polylactide (PLA) and poly(ethylene glycol) diacylate (PEGDA) monomer with no addition of exogenous radical initiators. Torque analysis and FT-IR spectra confirm that cross-linking reaction of acylate groups occurs in the melt blending process according to the free radical polymerization mechanism. The results from differential scanning calorimetry, phase contrast optical microscopy and transmission electron microscopy indicate that the in situ polymerization of PEGDA leads to a phase separated morphology with cross-linked PEGDA (CPEGDA) as the dispersed particle phase domains and PLA matrix as the continuous phase, which leads to increasing viscosity and elasticity with increasing CPEGDA content and a rheological percolation CPEGDA content of 15 wt %. Mechanical properties of the PLA materials are improved significantly, for example, exhibiting improvements by a factor of 20 in tensile toughness and a factor of 26 in notched Izod impact strength at the optimum CPEGDA content. The improvement of toughness in PLA/CPEGDA blends is ascribed to the jointly contributions of crazing and shear yielding during deformation. The toughening strategy in fabricating supertoughened PLA materials in this work is accomplished using biocompatible PEG-based polymer as the toughening modifier with no toxic radical initiators involved in the processing, which has a potential for biomedical applications.Keywords: biodegradable; mechanical property; morphology; phase separation; poly(ethylene glycol) diacylate; toughening

Wide range temperature detection with hybrid nanoparticles traced by surface-enhanced Raman scattering

Co-reporter:Jun Yin;YaGuang He;Wei Li;ZongQuan Wu

Science China Chemistry 2014 Volume 57( Issue 3) pp:417-425

Publication Date(Web):2014 March

DOI:10.1007/s11426-013-4974-x

We report on the fabrication of a class of surface-enhanced Raman scattering (SERS) active thermometers, which consists of 60 nm gold nanoparticles, encoded with Raman-active dyes, and a layer of thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) brush with different chain lengths. These SERS-active nanoparticles can be optimized to maintain spectrally silent when staying as single particles in dispersion. Increasing temperature in a wide range from 25 °C to 55 °C can reversibly induce the interparticle self-aggregation and turn on the SERS fingerprint signals with up to 58-fold of enhancement by taking advantage of the interparticle plasmonic coupling generated in the process of thermo-induced nanoparticles self-aggregation. Moreover, the most significative point is that these SERS probes could maintain their response to temperature and present all fingerprint signals in the presence of a colored complex. However, the UV-vis spectra can distinguish the differences faintly and the solution color shows little change in such complex mixture. This proof-of-concept and Raman technique applied here allow for dynamic SERS platform for onsite temperature detection in a wide temperature range and offer unique advantages over other detection schemes.

Effects of biodegradable imidazolium-based ionic liquid with ester group on the structure and properties of PLLA

Co-reporter:Haoguan Gui;Yu Li;Shouyu Chen;Pei Xu;Bin Zheng

Macromolecular Research 2014 Volume 22( Issue 6) pp:583-591

Publication Date(Web):2014 June

DOI:10.1007/s13233-014-2085-y

Blends of poly(L-lactide) (PLLA) and a functional ionic liquid (IL), 3-methyl-1-(ethoxycarbonylethyl) imidazolium tetrafluoroborate ([AOEMIm][BF4]) with various weight ratios were prepared by melt compounding and their interactions, compatibilities, processing characteristics, crystallization behaviors, mechanical properties and thermal degradation were investigated in this study. The interaction between PLLA and [AOEMIm][BF4] was first studied by infrared spectroscopy (IR) investigation, and then the Flory-Huggins interaction parameter between PLLA and [AOEMIm][BF4] was calculated. The compatibility was also supported by both sample appearance and scanning electron microscopy (SEM) results. Crystallization and melting conditions were obtained from differential scanning calorimetry (DSC), and the glass transition temperature (Tg) of PLLA showed a gradual decrease with the increasing addition of [AOEMIm][BF4]. The balancing torque data were obtained by Haaker torque rheometry, and the molecular weight data of processed PLLA obtained by gel permeation chromatography (GPC) tests reflected a positive effect of [AOEMIm][BF4] on the melt-processing of PLLA. A strong increase of the mechanical parameters of PLLA, such as the elongation at break and the impact strength, was observed with the incorporation of [AOEMIm][BF4] up to the content of 7 phr (phr is the abbreviation for parts per hundreds of resin, n phr denoted n g IL/100 g PLLA), while the tensile strength decreased slightly. The thermal stability of PLLA took a sustained downward trend, with the increasing contents of [AOEMIm][BF4] in its matrices, as presented from thermogravimetric analysis (TGA). PLLA blended with 5 phr [AOEMIm][BF4] achieved excellent overall performance; as well, the mechanical properties improved considerably, and damage to the thermal stability was acceptable.

Dielectric and conductivity properties of poly(L-lactide) and poly(L-lactide)/ionic liquid blends

Co-reporter:Pei Xu;Hao Guan Gui;Shan Zhong Yang;Yun Sheng Ding;Qian Hao

Macromolecular Research 2014 Volume 22( Issue 3) pp:304-309

Publication Date(Web):2014 March

DOI:10.1007/s13233-014-2038-5

Dielectric relaxation spectroscopy (DRS) was employed to study the dielectric and conductivity properties of poly(L-lactide) and poly(L-lactide)/ionic liquid (IL) blends. The experimental dielectric data were analyzed within the formalism of complex permittivity. The results were discussed in terms of AC conductivity, αN relaxation corresponding to the longest normal mode motion, α relaxation originating from the segmental mode motion, and DC conductivity. The results revealed that the motion of the polymer chains governs the charge carrier transport. The temperature dependence of the relaxation times follows the Vogel-Tammann-Fulcher (VTF) equation. The incorporation of IL into the matrix accelerates the segmental (α) and normal mode (αN) motions and the conductivity, and increases the charge carrier movement of IL following the longest αN motion of chains, which led to an increase in the relaxation strength of the αN relaxation.

Synthesis of a novel ionic liquid containing phosphorus and its application in intumescent flame retardant polypropylene system

Co-reporter:Xuefeng Yang;Nilin Ge;Liuyong Hu;Haoguan Gui;Zhigang Wang

Polymers for Advanced Technologies 2013 Volume 24( Issue 6) pp:568-575

Publication Date(Web):

DOI:10.1002/pat.3119

A novel ionic liquid containing phosphorus ([PCMIM]Cl) was synthesized and characterized by FTIR, ¹H NMR, ¹³C NMR and ³¹P NMR. Moreover, a new intumescent flame retardant (IFR) system, which was composed of [PCMIM]Cl and ammonium polyphosphate (APP), was used to impart flame retardancy and dripping resistance to polypropylene (PP). The flammability and thermal behaviors of intumescent flame-retarded PP (PP/IFR) composites were evaluated by limiting oxygen index (LOI), UL-94 test, thermogravimetric analysis (TGA) and cone calorimeter test. It was found that there was an obvious synergistic effect between [PCMIM]Cl and APP. When the weight ratio of [PCMIM]Cl and APP was 1:5 and the total amount of IFR was kept at 30 wt%, LOI value of PP/IFR composite reached 31.8, and V-0 rating was obtained. Moreover, both the peak heat release rate and the peak mass loss rate of PP/IFR composites decreased significantly relative to PP and PP/APP composite from cone calorimeter analysis. The TGA curves suggested that [PCMIM]Cl had good ability of char formation, and when combined with APP, it could greatly promote the char formation of PP/IFR composites, hence improved the flame retardancy. Additionally, the rheological behaviors and mechanical properties of PP/IFR composites were also investigated, and it was found that [PCMIM]Cl could also serve as an efficient lubricant and compatibilizer between APP and PP, endowing the materials with satisfying processability and mechanical properties. Copyright © 2013 John Wiley & Sons, Ltd.

Effect of ionic liquid on chain segment motion and charge detrapping in poly(l-lactide)/ionic liquid composites

Co-reporter:Pei Xu;Hao-guan Gui;Yun-sheng Ding

Ionics 2013 Volume 19( Issue 11) pp:1579-1585

Publication Date(Web):2013 November

DOI:10.1007/s11581-013-0901-6

The effect of ionic liquid on the chain segment motion and charge detrapping in poly(l-lactide) (PLA)/ionic liquid (IL) composites has been investigated by means of thermally stimulated depolarization current (TSDC), scanning electron microscopy, and differential scanning calorimetry. There are four current peaks (namely, α, ρ1, ρ2, and ρ3 peaks, respectively) in TSDC spectra of PLA and PLA/IL composites. The α peak corresponds to the glass transition, the ρ1 peak is attributed to space charge trapped in the amorphous phase, the ρ2 peak is originated from space charge trapped in the interphase that includes PLA/IL interface and crystalline/amorphous interface of PLA, and the ρ3 peak is originated from space charge trapped in the crystalline phase. With the increase of IL content from 0 to 5phr, ρ2 and ρ3 peaks gradually merge into one single peak. By analyzing the characteristic parameters of these peaks, it is found that IL can accelerate the mobility of chain segments and increase structural defects in PLA/IL composites. In addition, IL decreases the stability of trapped charge in both amorphous and crystalline phases, but not affecting the stability of trapped charge in interphase.

Structure and morphology controllable synthesis of Ag/carbon hybrid with ionic liquid as soft-template and their catalytic properties

Co-reporter:Shu Ying Wu, Yun Sheng Ding, Xiao Min Zhang, Hai Ou Tang, Long Chen, Bo Xuan Li

Journal of Solid State Chemistry 2008 Volume 181(Issue 9) pp:2171-2177

Publication Date(Web):September 2008

DOI:10.1016/j.jssc.2008.05.006

Ag/carbon hybrids were fabricated by the redox of glucose and silver nitrate (AgNO3) in the presence of imidazolium ionic liquid ([C14mim]BF4) under hydrothermal condition. Monodisperse carbon hollow sub-microspheres encapsulating Ag nanoparticles and Ag/carbon cables were selectively prepared by varying the concentration of ionic liquid. Other reaction parameters, such as reaction temperature, reaction time and the mole ratio of silver nitrate to glucose, play important roles in controlling the structures of the products. The products were characterized by XRD, TEM (HRTEM), SEM, energy-dispersive X-ray spectroscopy (EDX), FTIR spectroscopy and a Raman spectrometer. The possible formation mechanism was proposed. The catalytic property of the hybrid in the oxidation of 1-butanol by H2O2 was also investigated.Monodisperse carbon hollow nanospheres encapsulating Ag nanoparticles and Ag/carbon nanocables were selectively prepared with ionic liquids as the soft-template. The controllable synthesis of Ag/C nano-hybrids was realized by varying the concentration of ionic liquids, reaction temperature, reaction time and the mole ratio of silver nitrate to glucose. The catalysis of Ag/C nano-hybrid in the oxidation of 1-butanol by H2O2 was also investigated.

Effects of 1-n-tetradecyl-3-methylimidazolium bromide on the properties of polypropylene

Co-reporter:Yunsheng Ding;Haiou Tang;Xiaomin Zhang;Shuying Wu ;Renyan Xiong

Journal of Applied Polymer Science 2008 Volume 109( Issue 2) pp:1138-1142

Publication Date(Web):

DOI:10.1002/app.28032

Abstract

In this study, 1-n-tetradecyl-3-methylimidazolium bromide ([C₁₄mim]Br), one kind of imidazolium ionic liquids (imi-IL), was incorporated into polypropylene (PP) via melting blend. The structure and properties of PP/[C₁₄mim]Br blend were investigated by differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA), and thermogravimetric analysis (TGA). DSC results show that the [C₁₄mim]Br has effects on the melting and crystallization process so that PP and PP/[C₁₄mim]Br blends (weight ratio is 100/3) have different melting and crystallization temperature. Results of DMA show that the [C₁₄mim]Br has the effects on the plasticization and crystallization of PP, and the glass transition temperature (T_g) of PP decreases around 11°C when 3 weight shares of [C₁₄mim]Br were incorporated into 100 weight shares of PP. Moreover, both tensile strength and impact strength of PP have been improved reasonably in this situation. TGA also shows the thermal stability of PP is not affected by the [C₁₄mim]Br, which was incorporated into it though its molecule is small. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Synthesis of a kind of geminal imidazolium ionic liquid with long aliphatic chains

Co-reporter:Yun Sheng Ding, Min Zha, Jun Zhang, Seng Shan Wang

Chinese Chemical Letters 2007 Volume 18(Issue 1) pp:48-50

Publication Date(Web):January 2007

DOI:10.1016/j.cclet.2006.11.037

A novel geminal imidazolium ionic liquid with long hydrocarbon group, 1,4-bis (3-tetradecylimidazolium-1-yl) butane bromide was synthesized and an efficient synthesized method was introduced detailedly. Its structure was determined by FT-IR, 1H NMR and elemental analysis.

Synthesis, characterization and properties of geminal imidazolium ionic liquids

Co-reporter:Yun-Sheng Ding, Min Zha, Jun Zhang, Seng-Shan Wang

Colloids and Surfaces A: Physicochemical and Engineering Aspects 2007 Volume 298(Issue 3) pp:201-205

Publication Date(Web):1 May 2007

DOI:10.1016/j.colsurfa.2006.10.063

A novel geminal imidazolium ionic liquid with long hydrocarbon group, 1,4-bis(3-tetradecylimidazolium-1-yl) butane bromide was synthesized and its physicochemical properties were studied. To differentiate the novel ionic liquid with conventional ionic liquid, 1-n-tetradecyl-3-methylimidazolium bromide was also synthesized and their properties were compared. FT-IR, 1H NMR and elemental analysis were applied to identify the molecular structure of two compounds, then the crystal structures was investigate by the X-ray diffraction (XRD). Thermal properties of them were studied with thermogravimetry (TG) and differential scanning calorimetry (DSC). Critical micelle concentration (CMC) and surface tension of two compounds in aqueous solution were determined by maximum bubble pressure method. In this work, we also measured the water content in two compounds by using IR moisture meters, and polarity was studied by the solubility in a series of organic solvents. The results show that the new geminal imidazolium ionic liquid possesses higher thermal stability, lower CMC values and larger d-spacing of crystal structure than corresponding ionic liquid with single long chain.

Aggregative structure of the 1-octadecyl-3-methylimidazolium cation in the interlayer of montmorillonite and its effect on polypropylene melt intercalation

Co-reporter:Yunsheng Ding;Renyan Xiong;Sengshan Wang;Xiaomin Zhang

Journal of Polymer Science Part B: Polymer Physics 2007 Volume 45(Issue 11) pp:1252-1259

Publication Date(Web):16 APR 2007

DOI:10.1002/polb.21145

A series of organomontmorillonites were synthesized from pristine sodium montmorillonite via ion exchange in toluene with 1-octadecyl-3-methylimidazolium chloride, a kind of ionic liquid with high thermal stability, as a modifier. The amount and aggregative state of the 1-octadecyl-3-methylimidazolium cation ([C18mim]⁺) adsorbed in the interlayer of organomontmorillonite (MMT) were investigated with thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and differential scanning calorimetry. XRD patterns showed that [C18mim]⁺ was successfully intercalated into the interlayer of MMT, and the interlayer distances of the clays increased dramatically. On the basis of the TGA results, three types of arrangement models of [C18mim]⁺ could be seen, and they were related to the loading level of [C18mim]⁺ in the gallery of MMT. The effects of the aggregative structure of [C18mim]⁺ in the interlayer of MMT on polypropylene melt intercalation was also examined. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1252–1259, 2007

Physicochemical Adsorption and Aggregative Structures of the Organic Cation [C18mim]+ in the Interlayer of Montmorillonite

Co-reporter:Yunsheng Ding, Sengshan Wang, Min Zha, Zhigang Wang

Acta Physico-Chimica Sinica 2006 Volume 22(Issue 5) pp:548-551

Publication Date(Web):May 2006

DOI:10.1016/S1872-1508(06)60020-X

An organic cation [C18mim]+ formed from [C18mim]Br, a type of ionic liquid, can go into the interlayer of sodium montmorillonite (MMT) through the ion-exchanging reaction. The adsorption state, the adsorption amount, and the aggregative structures of [C18mim]+ in the interlayer of MMT have been investigated by thermogravimetric analysis (TGA), wide-angle X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results indicated that there is a maximum chemical adsorption of [C18mim]+ in the interlayer of MMT, but the total amount of adsorbed [C18mim]+ in the interlayer of MMT increases with that of the physical adsorption of [C18mim]+. With an increasing amount of adsorbed [C18mim]+ in the interlayer of MMT, the aggregative structures of [C18mim]+ become more ordered, leading to an obvious increase of the interlayer distance of MMT.

Adamantammonium as a novel functional group for anion exchange membranes with excellent comprehensive performances

Co-reporter:Jinlei Wang, Ying Chen, Qi Wei, Shanzhong Yang, Huagao Fang, Haibing Wei, Yunsheng Ding

Polymer (10 March 2017) Volume 112() pp:

Publication Date(Web):10 March 2017

DOI:10.1016/j.polymer.2017.02.030

•A novel adamantammonium cation with high alkaline stability for AEM applications was reported.•The benzyl type AEMs based on adamantammonium show improved alkaline durability than benzylmethylammonium-benchmark AEM.•The membranes exhibit high ionic conductivity and excellent dimensional stability.In the pursuit of alkali stable cation as functional group for anion exchange membranes (AEMs), a novel adamantammonium (AdA) cation, which replacing methyl group of conventional trimethylammonium by an adamantyl group, was synthesized and investigated. 1H NMR spectroscopy was employed to quantify the extent of decomposition and the results showed that > 99% adamantammonium remaining after 7 days immersion in 2 M NaOH (in D2O) at 80 °C. The AdA functionalized benzyl type poly(2,6-dimethyl phenylene oxide) polyelectrolytes, PPO-AdAs, were further prepared and characterized the AEM properties. Not only the chemical durability of these new PPO-AdA membranes, interestingly, but the conductivity and dimensional stability (water uptake and in-plane swelling) are superior to the benzylmethylammonium-benchmark PPO-based AEM (PPO-TMA). With the similar IEC values, the water uptake of PPO-AdA-41 sample is much lower than PPO-TMA-28, however, the conductivity of the former (15.7 mS cm-1, chloride conductivity at 50 °C) is higher than the latter (13.3 mS cm-1). Overall, the results of this study offer a base-stable cation, adamantammonium, and the corresponding adamantammonium-based AEMs for fuel cell applications with the advantages of chemical stability, enhanced conductivity and excellent dimensional stability as well as facial functionalization technique.Download high-res image (134KB)Download full-size image

Co-reporter:Xiaohong Wang, Hyun Ho Choi, Guobing Zhang, Yunsheng Ding, Hongbo Lu, Kilwon Cho and Longzhen Qiu

Journal of Materials Chemistry A 2016 - vol. 4(Issue 26) pp:NaN6400-6400

Publication Date(Web):2016/06/07

DOI:10.1039/C6TC01617K