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Luo F.,Sichuan University | Wang K.,Sichuan University | Ning N.,Sichuan University | Geng C.,Sichuan University | And 5 more authors.
Polymers for Advanced Technologies | Year: 2011

As part of a continuous effort to develop high performance isotactic polypropylene (iPP) based on β-form crystalline and morphological change induced by rare earth nucleator (WBG), various WBG contents (from 0.025 to 1.0wt%) were adopted to prepare β-nucleated iPP at a fixed final molten temperature (240°C) in this study. The crystallinity, polymorphic composition, and crystalline morphology were inspected in detail by a series of crystallographic characterizations, including calorimeter, X-ray diffraction, polarized light microscopy (PLM), and electron microscopy. Furthermore, the self-organization and re-crystallization behavior of β-nucleating agent occurred during cooling was characterized by rheometry. Finally, the dependence of mechanical properties, including tensile strength, elongation at break, and impact strength, on WBG content was discussed based on the variations in β-form content and crystalline morphology. Interestingly, it is found that while the WBG content is below 0.1wt%, the toughness of β-nucleated iPP increases with increase in WBG content due to additional β-form content; as the WBG content is in range of 0.1-0.5wt%, the toughness increases at a lower rate with increase in WBG content due to β-crystalline morphological change. However, a decrease in toughness is observed while nucleator content is above 0.5wt% as WBG remains undissolved in iPP upon the adopted processing conditions. The result of this study provides valuable information for potential industrial applications. © 2010 John Wiley & Sons, Ltd.


Zhang J.,Hebei University of Technology | Zheng D.,Guangdong Winner Functional Materials Co. | Liang X.,Guangdong Winner Functional Materials Co. | Li J.,Hebei University of Technology | And 2 more authors.
Gaofenzi Cailiao Kexue Yu Gongcheng/Polymeric Materials Science and Engineering | Year: 2012

WBG II is an efficient nucleating agent to prepare isotactic polypropylene (iPP) samples riching in β crystals. Depending on the melting tempreture (T melt), WBGII maybe partially or completely dissolve in the iPP melt. The structure and crystallization characteristics of the nucleated samples were studied by polarized light microscopy (PLM) and differential scanning calorimetry (DSC). It was found that the lateral surface of the needle crystals acted as β-nucleating agent when T melt was lower than 230°C. When T melt was higher than 230°C, we observed dendritic and microcrystalline structures, and a spectacular "flower"-like agglomerate. When T melt is different, iPP performs different crystallization behaviors.


Ding H.,Hebei University of Technology | Xiao S.,Hebei University of Technology | Wang H.,Hebei University of Technology | Chen X.,Hebei University of Technology | Zheng D.,Guangdong Winner Functional Materials Co.
Gaofenzi Cailiao Kexue Yu Gongcheng/Polymeric Materials Science and Engineering | Year: 2011

In the study, a new rare-earth β-nucleating agent (WBGII) was used to modify ethylene-propylene random copolymer (PPR). By means of wide-angle X-ray diffraction (WAXD), differential scanning calorimeter (DSC) and polarizing optical microscope (POM), the crystallization behavior and morphology of PPR induced by WBGII were studied. The effect of β nucleating agent on mechanical property and heat distortion temperature (HDT) was researched also. The results show that β-form nucleating agent WBGII can change the crystal structure of PPR and rise the maximums of exothermic peaks (Tc) of non-isothermal crystallization from 95.8°C to 102.1°C. The tensile and bend capability decrease a little and the impact strength increases by 24%. The HDT is risen by 20°C.


Ding H.-L.,Hebei University of Technology | Guo L.-Y.,Hebei University of Technology | Li D.-J.,Hebei University of Technology | Zheng D.,Guangdong Winner Functional Materials Co. | And 2 more authors.
Chinese Journal of Polymer Science (English Edition) | Year: 2015

In this study, the effect of annealing temperature on the impact toughness of β-nucleated polypropylene random copolymer (PPR) and ethylene-propylene-diene terpolymer (EPDM) blends was investigated by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). Interestingly, the impact strength of β-PPR/20EPDM blend annealed at 120 °C is 1.8 times as high as that of unannealed samples. In addition, the crystalline structure, the relaxation of chain segments and fracture morphology of β-PPR/EPDM blends were also investigated to explore the toughening mechanism related to annealing. The results show that annealing at moderate temperatures results in the improvement of integrity of the crystal structure and the relative content of β-phase. The work provides a possible method to toughen the semicrystalline polymer at low temperatures by annealing. © 2015, Chinese Chemical Society, Institute of Chemistry, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelberg.


Ren Y.-W.,South China University of Technology | Lu J.-X.,South China University of Technology | Cai B.-W.,South China University of Technology | Cai B.-W.,Guangdong Winner Functional Materials Co. | And 5 more authors.
Dalton Transactions | Year: 2011

A novel asymmetric phenol-based 'end-off' dinucleating ligand 2-{[(2-piperidylmethyl)amino]methyl}-4-bromo-6-[(1-methylhomopiperazine-4-yl) methyl]phenol (HL) and three dinuclear nickel(ii) complexes, [Ni 2L(μ-OH)] (ClO4)2 (1), [Ni 2L(DNBA)2(CH3CN)2]BPh4 (2) and [Ni2L(BPP)2(CH3CN)2]BPh 4 (3) have been synthesized and characterized by a variety of techniques including: NMR, infrared and UV-vis spectroscopies, mass spectrometry, elemental analysis, molar conductivity, thermal analysis, magnetochemistry and single-crystal X-ray diffractometry. The UV-vis spectrum of complex 1 exhibits a strong peak at 510 nm, a characteristic absorption of a d-d transition of the square-planar four-coordinated Ni(ii) center. Utilizing this feature, the stepwise formation of mono- and dinickel centers in solution can be monitored. Phosphodiesterase activity of a dinuclear Ni(ii) system (complex 1), formed in situ by a 2:1 mixture of Ni2+ ions and the ligand HL, was investigated using bis(4-nitrophenyl)phosphate (BNPP) as the substrate. The pH dependence of the BNPP cleavage in water-ethanol (1:1, v/v) reveals a bell-shaped pH-kobs profile with an optimum at about pH 8.3 which is parallel to the formation of the dinuclear species [Ni 2L(μ-OH)]2+, according to the increase of the peak at 510 nm in the UV-vis absorption spectrum. These studies reveal that the di-Ni(ii) system shows the highest catalytic activity reported so far, with an acceleration rate 1.28 × 107 times faster than the uncatalyzed reaction. The bridging hydroxyl group in [Ni2L(μ-OH)]2+ is responsible for the hydrolysis reaction. The possible mechanism for the BNPP cleavage promoted by di-Ni(ii) system is proposed on the basis of kinetic and spectral analyses. This study provides a less common example of the asymmetric phosphodiesterase model, which is like the active sites of most native metallohydrolases. © 2011 The Royal Society of Chemistry.


Ren Y.,South China University of Technology | Lu J.,South China University of Technology | Jiang O.,Guangdong Winner Functional Materials Co. | Cheng X.,South China University of Technology | Chen J.,Guangdong Winner Functional Materials Co.
Cuihua Xuebao/Chinese Journal of Catalysis | Year: 2015

A post-synthetic modification strategy has been used to prepare three solid base catalysts, including Er(btc)(ED)0.75(H2O)0.25 (2, btc = 1,3,5-benzenetricarboxylates, ED = 1,2-ethanediamine), Er(btc)(PP)0.55(H2O)0.45 (3, PP = piperazine), and Er(btc)(DABCO)0.15(H2O)0.85 (4, DABCO = 1,4-diazabicyclo[2.2.2]octane), by grafting three different diamines onto the coordinatively unsaturated Er(III) ions into the channels of the desolvated lanthanide metal-organic framework (Er(btc)). The resulting metal-organic frameworks were characterized by elemental analysis, thermogravimetric analysis, powder X-ray diffraction, and N2 adsorption. Based on its higher loading ratio of the diamine, as well as its greater stability and porosity, catalyst 2 exhibited higher catalytic activity and reusability than catalysts 3 and 4 for the Knoevenagel condensation reaction. The catalytic mechanism of 2 has also been investigated using size-selective catalysis tests. © 2015, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.


Cai B.,South China University of Technology | Cai B.,Guangdong Winner Functional Materials Co. | Ren Y.,South China University of Technology | Jiang H.,South China University of Technology | And 6 more authors.
Inorganic Chemistry Communications | Year: 2012

A novel lanthanide metal-organic framework (MOF), (bpy) [Eu (ip) 1.5(H 2O) 4] (bpy = 4,4′-bipyridine, ip = isophthalate) (1) has been synthesized via hydrothermal method. Single-crystal X-ray analysis reveals that the three-dimensional (3D) network is formed by one-dimensional (1D) chains through hydrogen bonds. The channel regions of the framework are host to neutral 4,4′-bipyridine molecules which serve as guest-templates. These 4,4′-bipyridine molecules do not coordinate to the metal centers but rather show hydrogen bond participation with metal-bound water molecules. The emission spectra show that 1 emits intense sharp red light when it is excited by different wavelength light of the absorption band. © 2011 Elsevier B.V. All rights reserved.


He B.-Y.,China University of Petroleum - Beijing | Guo S.-H.,China University of Petroleum - Beijing | Zheng D.,Guangdong Winner Functional Materials Co. | Qian Y.-Y.,Guangdong Winner Functional Materials Co. | Chen J.,Guangdong Winner Functional Materials Co.
Xiandai Huagong/Modern Chemical Industry | Year: 2011

In this paper, the development history and heat-treatment mechanism of microwave irradiation method for preparing rare earth inorganic material are briefly presented. The application classification and product characteristics of microwave irradiation method are discussed, and some initial exploration is done on the basis of previous studies.


Cai B.,South China University of Technology | Cai B.,Guangdong Winner Functional Materials Co. | Ren Y.,South China University of Technology | Jiang H.,South China University of Technology | And 4 more authors.
CrystEngComm | Year: 2012

A novel lanthanide metal-organic framework, {(bpy) 0.5[Dy 3(ip) 4(phen) 4(H 2O)]·2H 2O} n has been synthesized via a hydrothermal method. Single-crystal X-ray analysis reveals that the center ions are mixed-valence Dy (ii, iii) and that trans-2,2′-bipyridine was formed in situ from 1,10-phenanthroline under hydrothermal conditions in the presence of Dy(iii) ions. © 2012 The Royal Society of Chemistry.


Ren Y.-W.,South China University of Technology | Liang J.-X.,South China University of Technology | Lu J.-X.,South China University of Technology | Cai B.-W.,South China University of Technology | And 6 more authors.
European Journal of Inorganic Chemistry | Year: 2011

A series of new isostructural lanthanide MOFs, [Ln2(pda) 3(H2O)]·2H2O [Ln = La (1), Ce(2), Pr(3), Nd(4), Sm(5), Eu(6), Gd(7), Tb(8), Dy(9), Ho(10), Er(11), Tm(12), and Yb(13); H2dpa = 1,4-phenylenediacetate], have been solvothermally synthesized and structurally characterized by single-crystal (or/and powder) X-ray diffraction analysis. All the MOFs are isostructural and consist of 1D Ln-COO helixes that are cross-linked by the-CH2C6H 4CH2-spacers of the pda2- anions in a 3D compressed honeycomb-shaped network with 1D open channels, which accommodate guest and coordinated water molecules. Evacuation of [Ln2(pda) 3(H2O)]·2H2O at 200 °C under vacuum generates [Ln2(pda)3], which gives X-ray powder diffraction patterns consistent with those of [Ln2(pda) 3(H2O)]·2H2O. MOFs 6 and 8 show characteristic luminescent properties. Activated [Tb2(pda) 3] exhibits excellent catalytic performance in the heterogeneous acetalization of benzaldehyde with methanol. The possibility for easy recycling makes this catalyst a highly promising candidate to address environmental concerns. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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