Time filter

Source Type

Zhao T.-B.,University of Sichuan | Zhang X.-F.,University of Sichuan | Zhang X.-F.,Chengdu Institute of Product Quality Supervision and Inspection | Wu H.,University of Sichuan | Guo S.-Y.,University of Sichuan
Chinese Journal of Inorganic Chemistry | Year: 2014

The influence factors of 2-hydroxy-4-methoxy benzophenone-5-sulfonic acid (BP)-intercalated MgAl layered double hydroxides (MgAl-LDHs) reaction such as interlayer anionS’ solvent’ pH, values and reaction time, were investigated. The MgAl-BP-LDHs was prepared through anion-exchange under the optimal condition and characterized further by laser particle-size analysis, thermo-gravimetric analysis and ultraviolet-visible analysis, respectively. The XRD, results indicate that the optimal reaction condition for the BP-intercalated MgAl-LDHs (MgAl-BP-LDHs) with high intercalation rate is 48 h in deionized water with pH, value of 7. The results show that particle size distribution of the MgAl-BP-LDHs is narrower than that of MgAl-LDHs. The thermal stability of the MgAl-BP-LDHs is improved due to strong supramolecular interactions between MgAl-LDHs layers and BP, anions. Compared with MgAl-LDHs and BP, the ultraviolet absorption range and ability of the MgAl-BP-LDHs are increased greatly due to the synergistic effect. © 2014, Chinese Chemical Society. All rights reserved.

Li Y.,University of Sichuan | Lin Y.,University of Sichuan | Nie M.,University of Sichuan | Wang Q.,University of Sichuan | Zhang X.,Chengdu Institute of Product Quality Supervision and Inspection
Journal of Macromolecular Science, Part B: Physics | Year: 2016

Polypropylene (PP)glass fiber (GF) composites modified by maleic anhydride-grafted polypropylene (MAH-g-PP) were prepared and the thermal influence on the interfacial properties was characterized and discussed. The results showed that the migration of MAH-g-PP from the PP matrix onto the GF surface was a thermally activated process. To be more specific, with the increasing processing temperature, more MAH-g-PP migrated onto the interface region to bridge PP matrix and GF together and promote the interfacial interaction, resulting in more efficient applied load transfer to GF through the interface. Accordingly, the mechanical properties of PPGF composites were improved with increasing processing temperature. Moreover, based on the content of MAH-g-PP on the surface of the GF and the mobility of MAH-g-PP in the PPGF composites, a temperature-dependent mechanism for the enhanced interface was proposed. We suggest this study not only provides a guide to adjust processing parameters to prepare high-performance PPGF composite, but also would be applicable for other immiscible systems. © 2016 Taylor & Francis Group, LLC.

Zhang X.,University of Sichuan | Zhang X.,Chengdu Institute of Product Quality Supervision and Inspection | Pi H.,University of Sichuan | Guo S.,University of Sichuan
Polymer Engineering and Science | Year: 2013

The photostabilizing efficiency of different light stabilizers in poly(vinyl chloride) (PVC) was investigated by discoloration, ultraviolet (UV) reflection experiment, Fourier transform infrared spectrum (FTIR), and scanning electron microscopy (SEM). The results show that the addition of light stabilizers can slow down discoloration of PVC. The UV reflection results verify that this change is due to the distribution of light stabilizers on irradiated surfaces, which can absorb (such as organic stabilizers) or reflect (such as titanium dioxide) UV light differently. The order of stabilizers that can slower the extent of discoloration is titanium dioxide (TiO2) > Tinuvin 234 (U4) > XT 833 (H2), U4 > Tinuvin 531 (U3) > Chimassorb 944 (H1), phenyl salicylate (U1). FTIR results show that the carbonyl group of pure PVC, TiO2, and H1-doped PVC increases significantly, indicating that the photo-oxidation reactions of these irradiated samples are relatively serious. The SEM results show that the surface damages of PVC doped with U2, U4, and H2 are somehow slighter, with only small holes or cavities on the surface, whereas the surfaces of pure PVC and H1-doped PVC are full of big and deep holes and some holes or cavities of 10 μm are detected. Copyright © 2012 Society of Plastics Engineers.

Lin N.,University of Sichuan | Lin N.,Yibin University | Ai T.-B.,University of Sichuan | Ai T.-B.,Chengdu Institute of Product Quality Supervision and Inspection | And 5 more authors.
Biochemistry (Moscow) | Year: 2013

A putative fatty acyl-acyl carrier protein (acyl-ACP) thioesterase (thioesterase) full-length cDNA sequence named as ClFATB1 was obtained from the seed cDNA library of Cinnamomum longepaniculatum by the SMART-RACE method. The novel gene encodes a protein of 382 amino acid residues with close homology to fatty acid thioesterase type B (FATB) enzymes of other plants, with two essential residues (His285 and Cys320) for thioesterase catalytic activity. The gene was transcribed in all tissues of C. longepaniculatum, the highest being in seeds. Recombinant ClFATB1 in Escherichia coli had higher specific activities against saturated 16:0- and 18:0-ACPs than on unsaturated 18:1-ACP. Overexpression of ClFATB1 in transgenic tobaccos upregulated thioesterase activities of crude proteins against 16:0-ACP and 18:0-ACP by 20.3 and 5.7%, respectively, and resulted in an increase in the contents of palmitic and stearic acids by 15.4 and 10.5%, respectively. However, ectopic expression of this gene decreased the substrate specificities of crude proteins to unsaturated 18:1-ACP by 12.7% in transgenic tobacco and lowered the contents of oleic, linoleic, and linolenic acids in transgenic leaves. So ClFATB1 would potentially upregulate the synthesis of saturated fatty acids and downregulate unsaturated ones in the fatty acid synthesis pathway of plants. © 2013 Pleiades Publishing, Ltd.

Zhang X.,University of Sichuan | Zhang X.,Chengdu Institute of Product Quality Supervision and Inspection | Zhao T.,University of Sichuan | Pi H.,University of Sichuan | Guo S.,University of Sichuan
Journal of Applied Polymer Science | Year: 2012

The Mg-Al oxide precursor prepared by the calcination of Mg-Al-carbonated layered double hydroxide (LDH) at 500 K for 4 h is used as the host material, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (BP) is used as the guest material, BP-intercalated LDH (LDH-BP) is prepared by ion-exchange method. The structure of LDH-BP is characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermogravimetry and differential thermal analysis (TG-DTA). The thermal stability of PVC/BP, PVC/LDH, PVC/LDH-BP composites, as well as pure PVC is investigated by conventional Congo Red test and dynamic thermal stability analysis in both the open and closed processing environments. According to XRD and FTIR, BP anions have been intercalated into interlayer galleries of LDH. TG-DTA results show that the layer-anionic interaction results in the improvement of the thermal stability of BP. Congo Red tests indicate that the addition of BP catalyzes the thermal degradation of PVC. A little amount of LDH (such as 1 phr) makes PVC more stable, but excessive addition accelerates the thermal degradation of PVC. The addition of LDH-BP markedly improves the static thermal stability of PVC. The results of dynamic thermal stability tests in both the open and closed processing environments are consistent with that of Congo Red tests. Copyright © 2011 Wiley Periodicals, Inc.

Discover hidden collaborations