Liaoning Key Laboratory of Polymer Science and Engineering

Dalian, China

Liaoning Key Laboratory of Polymer Science and Engineering

Dalian, China
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Tan R.,Dalian University of Technology | Tan R.,Liaoning Key Laboratory of Polymer Science and Engineering | Guo F.,Dalian University of Technology | Guo F.,Liaoning Key Laboratory of Polymer Science and Engineering | And 2 more authors.
Polymer Chemistry | Year: 2017

The homopolymerization of propylene and its copolymerization with styrene and ethylene catalyzed by half-sandwich scandium complexes bearing different ligands were carried out. A significant influence of alkyl and THF ligands on the propylene polymerization activity has been observed. The THF-containing trimethylsilylmethyl complex (C5Me4SiMe3)Sc(CH2SiMe3)2(THF) (4) in combination with one equivalent of [Ph3C][B(C6F5)4], can serve as a high activity catalyst for the atactic polymerization of propylene. By using this high activity catalyst, the copolymerization of propylene with styrene has been achieved to afford multi-block propylene-styrene copolymers with syndiotactic styrene-styrene blocks. Moreover, a novel family of random propylene-ethylene-styrene terpolymers with a broad composition range, relatively high molecular weights and narrow molecular weight distributions was effectively obtained by the terpolymerization of propylene with ethylene and styrene in the presence of 4/[Ph3C][B(C6F5)4]. The incorporation of styrene units into atactic polypropylene or ethylene-propylene copolymers can be controlled in a wide range simply by changing the monomer feed ratios. © 2017 The Royal Society of Chemistry.


Tan R.,Dalian University of Technology | Tan R.,Liaoning Key Laboratory of Polymer Science and Engineering | Shi Z.,Dalian University of Technology | Shi Z.,Liaoning Key Laboratory of Polymer Science and Engineering | And 8 more authors.
Polymer Chemistry | Year: 2017

The terpolymerization of ethylene and propylene with isoprene was performed catalyzed by half-sandwich scandium complexes (C5Me4SiMe3)Sc(CH2SiMe3)2(THF) (1) and [1,3-(Me2Si)2C9H5]Sc(CH2SiMe3)2 (THF) (2) in combination with 1 equiv. of [Ph3C][B(C6F5)4]. The terpolymers with ethylene contents of 60-84 mol% and isoprene contents of 5-26 mol% (1,4/3,4 ≈ 50/50) were obtained in the presence of complex 1. In comparison, the terpolymers with ethylene contents of 38-75 mol% and isoprene contents of 4-43 mol% (1,4/3,4 ≈ 70/30) were obtained in the presence of complex 2. Subsequently, a functionalized ethylene-propylene-isoprene terpolymer was prepared by the epoxidation of the 1,4-isoprene units in the terpolymer backbone and further hydroxylation/chlorination through ring-opening reaction of the epoxy groups. © 2017 The Royal Society of Chemistry.


Hu L.,State Key Laboratory of Fine Chemical | Hu L.,Liaoning High Performance Polymer Engineering Research Center | Hu L.,Liaoning Key Laboratory of Polymer Science and Engineering | Hu L.,Dalian University of Technology | And 9 more authors.
Applied Surface Science | Year: 2012

Novel thermally stable composite nanofiltration (NF) membranes were prepared from piperazine (PIP) and trimesoyl chloride (TMC) on poly (phthalazione ether nitrile ketone) (PPENK) ultrafiltration (UF) membranes by interfacial polymerization. The effects of monomers concentration, reaction time and organic solvents on the performance of composite membranes were investigated. The effects of operating pressure and the salt solution concentration on the performance of composite membranes were also discussed. The different salts rejection of PPENK composite membranes decreased in the order of Na 2SO 4 > MgSO 4 > Al 2(SO 4) 3 > NaCl > MgCl 2, which indicated a negative charge at the membrane surface. The flux and Na 2SO 4 rejection of PPENK composite membranes reached 57.9 L/m 2 h and 98.4% under the optimized conditions and operating pressure of 1.0 MPa. Furthermore, the morphology and chemical structure of membranes were examined by scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. Moreover, the thermal stability of PPENK NF membranes was also investigated. When temperature of the feed solution raised from 20°C to 80°C, the permeation flux increased about four times without significant change of rejection. The flux increased first then reached a plateau and the rejection kept constant when PPENK NF membranes in boiling de-ionized water were boiled to 3 h. © 2012 Elsevier B.V. All rights reserved.


Han L.,Dalian University of Technology | Han L.,Liaoning Key Laboratory of Polymer Science and Engineering | Ma H.,Dalian University of Technology | Ma H.,Liaoning Key Laboratory of Polymer Science and Engineering | And 8 more authors.
Macromolecules | Year: 2015

A new series of linear-comb and 4-arm star-comb side chain liquid crystalline polymers (Lc-/Sc-SCLCPs) have been synthesized and characterized. The treatment of hydride siloxane-containing terminated liquid crystalline and high 1,2-/1,4- (high vinyl, hv/low vinyl, lv) linear or 4-arm star polybutadienes (L-/S-PBs) was conducted via the methods in combination of living anionic polymerization and "reverse" hydrosilylation to obtain SCLCPs with wide mesomorphic temperature range (ΔT) and narrow polydispersity index (PDI). The possible molecular arrangement model of two analogous hv-/lv-architectures was constructed, that was used to systematically investigate the effects of Lc- and Sc- topological morphology on liquid crystalline (LC) properties and molecular microstructures. SCLCPs exhibited the same smectic A phase around room temperature, but thermal properties were significantly different due to differences of interaction force resulting from different macromolecular side chains packing. Surprisingly, the trend of lv-SCLCP displaying the effects of topology on phase transitions and microstructures was just contrary to that of hv-topology. hv-Sc-SCLCPs containing high density mesogenic composition were desired to generate wider ΔT and higher molecular layer order in comparison with Lc analogues, which provided a unexpected analyzed model that are of interest to be explored. In particular, the uniaue differences of macromolecular aggregation state arrangement in liquid crystal state dependent on free cooling between hv-Lc- and Sc-SCLCPs were observed from POM. © 2015 American Chemical Society.


Li Y.,Dalian University of Technology | Dong S.,Dalian University of Technology | Zhang C.,Dalian University of Technology | Zhang C.,Liaoning Key Laboratory of Polymer Science and Engineering
Hecheng Shuzhi Ji Suliao/China Synthetic Resin and Plastics | Year: 2014

A trimethoxysilane-terminated homopolystyrene (PS) was prepared via a route combining living anionic polymerization and modification process of end-groups. Then PS/SiO2 hybrid materials were synthesized by sol-gel process. The structure and properties of the PS/SiO2 hybrid materials were analyzed by infrared spectroscopy (IR), gel permeation chromatograph (GPC), differential scanning calorimetry (DSC), thermogravimetry (TG) and scanning electron microscope (SEM). The results indicate that the PS/SiO2 hybrid materials have chemical bonds between PS and SiO2. And there are SiO2 particles in perfect spherical structure with diameter of about 180 nm evenly distributing in the hybrid materials when the mass percentage of SiO2 is 25%. The glass transition temperature of the hybrid materials is 1.3℃ higher than that of pure PS, and the thermostability of the former is superior to that of the latter.


Zhang Y.,Dalian University of Technology | Zhang Y.,Liaoning Key Laboratory of Polymer Science and Engineering | Guo F.,Dalian University of Technology | Guo F.,Liaoning Key Laboratory of Polymer Science and Engineering | And 6 more authors.
Polymer (United Kingdom) | Year: 2014

A series of multicoumarin-functionalized dendrigraft polybutadienes with linear-comb or star-comb topology were synthesized from generation 0 to 3 (LGn and SGn respectively, n = 0-3) to investigate the dendritic effects on photophysical and fluorescence properties. From the results of SEC-TALLS, SEC and ubbelohde viscometer, the polymer architecture converted from one-or two-dimensional structure to a flexible branched structure, then advanced into a compact structure; meanwhile, the LGn exhibited a relatively looser structure than its SGn analog did. Hypsochromic shifts of the absorption and emission maxima, as well as signal amplifications were observed for both LG3 and SG3, suggesting that encapsulation effect occurred at the third generation resulting from the compact architecture. The fluorescence quantum yield (ΦF) was in the order of LG1 (8.1%) > SG1 (6.4%) > LG2 (5.0%) > SG2 (4.6%) > LG3 (2.3%) > SG3 (2.0%) > SG0 (1.1%) > LG0 (0.7%), indicating that the flexible branched polymer matrix could enhance the fluorescence properties due to the synergistic combination of inter-/intra-molecular fluorescence quenching. Also, the fluorescence properties of polymer with linear-comb architecture were always better than those of star-comb counterpart due to its looser architecture. © 2013 Elsevier Ltd. All rights reserved.


Han L.,Dalian University of Technology | Han L.,Liaoning Key Laboratory of Polymer Science and Engineering | Ma H.,Dalian University of Technology | Ma H.,Liaoning Key Laboratory of Polymer Science and Engineering | And 16 more authors.
Macromolecules | Year: 2016

A versatile strategy is highly desired to prepare well-designed side chain liquid crystal polymers (SCLCPs). Two rigid and topological SiH/Vinyl-functionalized polystyrenes (PSs), namely poly(4-vinylphenyldimethylsilane) (PVPDMS) and poly(4-vinylphenyl-1-butene) (PVSt), were synthesized via anionic polymerization (AP) and detailed; subsequently, Vinyl/SiH terminated LCs were treated with PVSt/PVPDMS via hydrosilylation to yield SCLCPs bearing [Si-O-Si]/[Si-C] spacers. Herein, well-designed grafting density, evaluated by 1H NMR, was readily performed by the varying SiH to Vinyl feed mole ratio. The design systematically probes a cooperative effect of architectures on properties and allows for precision in flexible/rigid matrixes. Regardless, PB/PS systems with saturated addition displayed the best performances. Fundamentally, the study compared the dependence of polarized optical and thermal performances on [Si-O-Si] versus [Si-C] spacer, which submitted to be driven by grafting density, providing the first access to tailoring polymer. SCLCPs exhibited essentially constant SmA, but inconsistent dynamic of spacer-induced contribution, in which ΔT was the same in complete addition as if nothing with spacer; surprisingly, followed by decreased grafting density, the decreasing trend in ΔT of [Si-O-Si] as spacer was fast, while that of [Si-C] was slow. This phenomenon was further confirmed by POM. Furthermore, [Si-O-Si] was desired to obtain lower Tg and applicable to the advantageous "decoupling effect". Endeavor for tailoring SCLCPs and regulating devices, the appropriate spacer and grafting density advanced to an effective role. © 2016 American Chemical Society.


Zhang Y.,Dalian University of Technology | Zhang Y.,Liaoning Key Laboratory of Polymer Science and Engineering | Shen K.,Dalian University of Technology | Shen K.,Liaoning Key Laboratory of Polymer Science and Engineering | And 6 more authors.
RSC Advances | Year: 2013

This paper demonstrated fluorescence behaviour of two novel coumarin-containing dendrigraft polybutadienes (PB-Cou) with linear-comb (LC-PB-Cou) and star-comb (SC-PB-Cou) architectures. LC-PB-Cou and SC-PB-Cou with 12-13 mol% coumarin content were synthesized via the combination of anionic polymerization and "click" chemistry methodology. The photophysical behaviours were investigated based on UV-Vis spectroscopy and fluorescence spectroscopy. The tailor-made LC-PB-Cou and SC-PB-Cou were designed to possess almost identical branching parameters except for architecture. The results of the study suggested that the fluorescent properties of coumarin were improved after being introduced into the dendrigraft polymer. The fluorescence quantum yield (ΦF) of LC-PB-Cou (7.3%) and SC-PB-Cou (5.4%) significantly increased, compared with that of coumarin itself (1.7%). Furthermore, LC-PB-Cou had the advantage over SC-PB-Cou in fluorescent properties because of its looser conformation. © The Royal Society of Chemistry 2013.


Guan S.,Dalian University of Technology | Zhang S.,State Key Laboratory of Fine Chemical | Zhang S.,Liaoning High Performance Polymer Engineering Research Center | Zhang S.,Liaoning Key Laboratory of Polymer Science and Engineering | And 7 more authors.
Applied Surface Science | Year: 2014

Sulfonated copoly (phthalazinone biphenyl ether sulfone) (SPPBES) composite nanofiltration membranes were fabricated by adding low molecular weight additives into SPPBES coating solutions during a dip coating process. Three selected additives: glycol, glycerol and hydroquinone were used in this work. The effect of additives on the membrane performance was studied and discussed in terms of rejection and permeation flux. Among all the composite membranes, the membrane prepared with glycol as an additive achieved the highest Na 2SO4 rejection, and the membrane fabricated with glycerol as an additive exhibited the highest flux. The salts rejection of SPPBES composite membranes increased in the following order MgCl2 < NaCl ≤ MgSO4 < Na2SO4. The morphologies of the SPPBES composite membranes were characterized by SEM, it was found that the membrane prepared with hydroquinone showed a rough membrane surface. Composite membrane fabricated with glycol or glycerol as the additive showed very good chemical stability. © 2014 Elsevier B.V. All rights reserved.


Zhang B.,Dalian University of Technology | Zhang S.,Dalian University of Technology | Zhang S.,Liaoning Key Laboratory of Polymer Science and Engineering | Xing D.,Dalian University of Technology | And 5 more authors.
Journal of Power Sources | Year: 2012

To develop cost-effective membranes with low permeability of vanadium ions for vanadium redox flow battery (VRB) application, an inexpensive precursor membrane material, chloromethylated poly(phthalazinone ether ketone ketone), is first prepared from poly(phthalazinone ether ketone ketone) with nitrobenzene as the solvent, and then reacted with trimethylamine to form quaternized poly(phthalazinone ether ketone ketone) (QAPPEKK) anion exchange membranes. At an ion exchange capacity of 1.56 mmol g -1, the QAPPEKK membrane shows much lower permeability of vanadium ions (0.17 × 10 -4 cm min -1 for V 3+ and 0.21 × 10 -4 cm min -1 for VO 2+) than that of Nafion117 membrane (1.34 × 10 -4 cm min -1 for V 3+ and 1.19 × 10 -4 cm min -1 for VO 2+), resulting in higher coulombic efficiency (99.4% at 80 mA cm -2). In addition, the energy efficiency of the VRB with QAPPEKK membrane is comparable to that of VRB with Nafion117 membrane. Moreover, the QAPPEKK membrane is stable in VO2+ electrolyte, and exhibits good performance in the 100-cycle charge-discharge test of VRB. © 2012 Elsevier B.V. All rights reserved.

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