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911.
912.
Determination of Fatty Acid Methyl Esters in Biodiesel Produced from Yellow Horn Oil by LC 总被引:2,自引:0,他引:2
Yu-Jie Fu Yuan-Gang Zu Li-Li Wang Nai-Jing Zhang Wei Liu Shuang-Ming Li Su Zhang 《Chromatographia》2008,67(1-2):9-14
A simple and accurate HPLC method with refractive index detection was developed to determine the main fatty acid methyl esters
in biodiesel produced from yellow horn oil. Methyl linoleate, methyl linolenate, methyl arachidate, methyl stearate, methyl
palmitate and methyl oleate were separated on a HIQ SIL C18W column using methanol as mobile phase. The method has good repeatability
and precision, the intraday and interday RSD for both retention time and peak area was less than 3.2%. The LOD (S/N = 3) and
LOQ (S/N = 9) were less than 0.004 and 0.015 mg mL−1, respectively. 相似文献
913.
914.
915.
916.
Yaqin Fu Minghao Sun Yonggang Wu Zhishan Bo Dongge Ma 《Journal of polymer science. Part A, Polymer chemistry》2008,46(4):1349-1356
Conjugated polymers containing electron‐transporting, hole‐transporting, and blue light‐emitting units were synthesized by Suzuki polycondensation. These copolymers exhibited excellent thermal and optical stability. Optical investigation indicated that the incorporation of the spirobifluorene units in the polymer main chain could markedly increase the effective conjugation length of polymers. Electrochemical studies showed that the incorporation of spirobifluorene unit could raise the electrochemical stability and improve the electron‐ and hole‐injecting abilities. The electroluminescent results also showed that the introducing of spirobifluorene units could significantly improve the device performance. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1349–1356, 2008 相似文献
917.
Jianhua Liu Yusong Wang Qi Fu Xiangyang Zhu Wenfang Shi 《Journal of polymer science. Part A, Polymer chemistry》2008,46(4):1449-1459
A simple mathematic model for the free radical polymerization of chain transfer monomers containing both polymerizable vinyl groups and telogen groups was proposed. The molecular architecture of the obtained polymer can be prognosticated according to the developed model, which was validated experimentally by homopolymerization of 4‐vinyl benzyl thiol (VBT) and its copolymerization with styrene. The chain transfer constant (CT) of telogen group in a chain transfer monomer is considered to play an important role to determine the architecture of obtained polymer according to the proposed model, either in homopolymerization or copolymerization. A highly branched polymer will be formed when the CT value is around unity, while a linear polymer with a certain extent of side chains will be obtained when the CT value is much bigger or smaller than unity. The CT of VBT was determined to be around 15 by using the developed model and 1H NMR monitored experiments. The obtained poly(VBT) and its copolymers were substantiated to be mainly consisted of linear main chain with side branching chains, which is in agreement with the anticipation from the developed model. The glass transition temperature, number average molecular weight, and its distribution of those obtained polymer were primarily investigated. This model is hopefully to be used as a strategy to select appropriate chain transfer monomers for preparing hyperbranched polymers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1449–1459, 2008 相似文献
918.
Li Cui Jen‐Taut Yeh Ke Wang Qiang Fu 《Journal of Polymer Science.Polymer Physics》2008,46(13):1360-1368
An investigation of miscibility and isothermal crystallization behavior of Polyamide 6 (PA6)/Poly(vinyl alcohol) (PVA) blends was conducted. Fourier transform infrared spectra (FTIR) analysis indicated that the interactions between the carbonyl groups of PA6 and hydroxyl groups of PVA increase as the weight ratios of PA6 to PVA of PA6/PVA specimens increase. This interaction between PA6 and PVA leads to their miscibility in the amorphous region and even some extent effects on their crystal phase, respectively. Further isothermal crystallization behavior of PA6/PVA indicate that the miscibility of PVA in PA6 leading difficulty in crystallization of PA6. Several kinetics equations are employed to describe the effects of PVA on the crystallization properties of PA6 in PA6/PVA blends in detail. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1360–1368, 2008 相似文献
919.
N-Octadecyl-N′-maleoyl-L-phenylalanine(ODMA-L-Phe)was synthesized through the condensation,deprotection and acid- ylation reaction of BOC-L-phenylalauine,octadecylamine and maleic anhydride,ODMA-L-Phe can self-assemble in some organic solvents and turned them into thermally reversible physical supramolecular organogels.The morphology of ODMA-L-Phe aggregates was characterized by polarized optical microscopy(POM)and field emission scanning electron microscope(FE-SEM). The aggregates of ODMA-L-Phe were needle-like fibrils with diameters of approximately 100-200 nm.The mechanism of ODMA- L-Phe serf-assembly in organic solvents was investigated using ~1H NMR and circular dichroism(CD).The results indicated that hydrogen bonding was one of the main driving forces for the self-assembly of ODMA-L-Phe. 相似文献
920.
Xiaogang Yang Dongsheng Li Feng Fu Long Tang Jiyuan Yang Lili Wang Yaoyu Wang 《无机化学与普通化学杂志》2008,634(14):2634-2638
The reaction of ZnII nitrate with maleic acid (H2mal) / fumaric acid (H2fum) and 4,4′‐dipyridyl disulfide (4‐pds) resulted under same conditions in two distinct interpenetrated compounds, namely [Zn(4‐dps)2(H2O)2]·2Hmal ( 1 ) and [Zn(4‐dps)(fum)] ( 2 ). In 1 , Hmal anion adopts bridging mode based on hydrogen bonding, affording a 2‐fold parallel interpenetrated 3D→3D α‐Po net hydrogen‐bonded framework, in which 1D double‐stranded chains are formed, and then extended to a 3D supramolecular architecture combining second‐sphere hydrogen‐bonded interactions. For 2 , fum dianion takes on bis‐dentate bridging coordination fashion, furnishing a 2‐fold interpenetrated 2D→2D (4,4) layered coordination network, in which the tetrahedral ZnII atoms are interlinked by 4‐dps and fum. Additionally, the compound 2 shows strong fluorescence in the solid state at room temperature. 相似文献