Studies on Blends of Nylon 6 and a Thermotropic Liquid Crystalline Polyarylester(Ⅱ)——Morphology and Rheology

Blends of nylon 6 (PA6) and a semirigid thermotropic liquid crystalline polyarylester (THH) were prepared by coprecipitation. The changing of the morphology of the blends with their compositions was observed by means of a polarizing microscope and scanning electron microscope. The THH phases in the blends changed gradually from spherical droplets to fibrils with the increase of THH content. The flow behavior of the blends are quite different from that of the parent polymers and a very dramatic reduction in the melt viscosity of blends containing 5% THH was observed. The formation possibility of in-situ reinforcement composites of PA6 blends with a semirigid LCP is discussed in the present paper.     

The Studies of A New Type of Crystalline Antimonic Acid

A new type of crystalline antimonic acid Sb2O5 ·3H2O was synthesized. The composition, crystal structure, the equilibrium distribution coefficients for sodium and potassium ions and the ion-exchange capacity of this exchanger were determined. With this exchanger, sodium ions were removed from potassium chloride, and the content of sodium chloride was reduced from 3.24 % to 0.02% .Compared with other ion-exchange materials, the crystalline antimonic acid gives an unusual selectivity for potassium and sodium ions . The different compositions and properties of antimonic acid exchangers are obtained through different preparing conditions and its crystalline formula of Sb2O5 ·4H2O[2](C-SbA1) is currently accepted. This paper reports a new type of crystalline antimonic acid-Sb2O65·3H2O(C-SbA2), synthesized by an improved Kuzin's method[3]. Sodium ions are removed from potassium chloride with C-SbA2. The exchange efficiency is better than that of C-SbA1.     

The Rheological and Extrusion Behaviour of Blends Based on Phenolphthalein Poly(ether-ether-sulfone) and Thermotropic Liquid Crystalline Polymer

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FTIR Spectroscopic Studies on the Conformational Equilibrium of Liquid 2,4-Dimethyl-1,3-Pentadiene

Investigations of 2,4-dimethyl-1,3-pentadiene by variable temperature FTIR spectra have concluded that the compound is a mixture of two kinds of single bond isomer,i.e.,s-traiis and s-cis conformers.The changes of IR band intensities have been recorded at research temperature range.The values of △H° and △S° between two stable conformers have been deduced to be 4.37 kJ/mol and 2.48 J/mol K respectively.     

Effect of a Nematic Liquid Crystalline Polymer as Highly Active β-Nucleator on Crystallization Structure and Morphology of Isotactic Polypropylene

The effects of nematic liquid crystalline polymer as a new β-nucleator (LCP-N) on crystallization structure and morphology of isotactic polypropylene (iPP) were investigated using wide-angle X-ray diffraction and polarized optical microscopy. The experimental results showed that LCP-N could lead to substantial changes in the crystallization structure and morphology of iPP. The nucleating activity of LCP-N mainly depended on its content, mesogenic molecules, and thermal history of processing. A high content of β-form (K _β) was obtained by the combined effect of the optimum LCP-N content and crystallization temperature. The maximum K _β reached 84% when the LCP-N content and crystallization temperature and time were 0.4 wt.%, 125°C, and 1 h, respectively. In addition, the birefringence of β spherulite was stronger than that of α spherulite; this difference is related to their particular way of growing and lamellar morphology. Due to its particular sheaf-like growth, the β spherulite was brighter and more colorful.     

Synthesis of a New Liquid Crystalline Polymer as a Highly Active β-Nucleator and Its Effect on Melting and Crystallization Behaviors of Isotactic Polypropylene

A new nematic liquid crystalline polymer as a highly active β-nucleator (LCP-N) of isotactic polypropylene (iPP) was synthesized and characterized. The effect of LCP-N on thermal behavior of the iPP was investigated with differential scanning calorimetry. LCP-N showed a melting transition at 85.0°C and a nematic to isotropic phase transition at 278.0°C. The incorporation of LCP-N could lead to substantial changes in the thermal behavior of the iPP. The nucleating activity of LCP-N mainly depended on its content, mesogenic molecular structure, and thermal history of processing. A high content of β-form could be obtained by the combined effect of the optimum LCP-N concentration and crystallization temperature and time. The Φ_β reached 77% when the LCP-N content, crystallization temperature, and crystallization time were 0.4 wt.%, 125°C, and 1 h, respectively.     

Synthesis,Structure and Characterization of a Cd(Ⅱ) Polymer Based on 6-Hydroxynicotinic Acid

A new 2D layered Cd(II) coordination polymer,[Cd(HnicO)(phen)(NO3)]n 1(H2nicO = 6-hydroxynicotinic acid,phen = 1,10-phenanthroline),has been hydrothermally synthesized and characterized by elemental analysis,IR,and single-crystal X-ray diffraction.It crystallizes in the monoclinic system,space group P21/c with a = 11.1107(2),b = 13.7639(2),c = 12.1457(4) ,β = 108.695(1)°,V = 1759.40(7) 3,Z = 4,Mr = 492.72,F(000) = 976,Dc = 1.860 g/cm3,μ = 1.289 mm-1,the final R = 0.0205 and wR = 0.0550 for 3663 observed reflections(I > 2σ(I)).X-ray single-crystal structural analyses reveal that in complex 1,the H2nicO ligands and Cd(II) nodes define the structure to be(4,4) 2D nets which are further assembled into the final 3D architecture via supramolecular interactions such as hydrogen bonds and aromatic interactions.Moreover,the solid-state luminescent study shows the title polymer possesses intense luminescent property at room temperature.     

X-Ray Photoelectron Spectroscopic Study on the Synthesis of Copper Sulphide in LB Films( Ⅱ )

The present paper covers the formation process of copper sulphide in copper stearate Langmuir-Blodgett films studied carefully by XPS. The further identification of sulfur species and the examination of its change in the reaction have been made. Also the formation mechanism of sulfur species in the special microenvironment-LB films is discussed.     

Scanning Tunneling Microscopic and Scanning Tunneling Spectroscopic Studies of Nanocrystalline CdSe Thin Film

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Synthesis,Structure and Luminescent Properties of a Two-dimensional Cobalt(Ⅱ) Coordination Polymer Based on 2-Thiobarbituric Acid

A two-dimensional coordination polymer [Co(H_2tba)_2(DMF)_2]_n 1(H_2tba = 2-thiobarbituric acid anion, DMF = N,N-dimethylformamide) has been synthesized by Co Cl2·6H2O with the 2-thiobarbituric acid ligands under solvothermal conditions. Compound 1 was further characterized by FTIR, elemental analysis, TGA and powder XRD techniques. Single-crystal X-ray diffraction studies revealed that the title compound crystallizes in the monoclinic space group Pbca with a = 12.5948(12), b = 11.4269(11), c = 14.8939(15) ?, V = 2143.5(4) ?~3, Z = 4, Dc = 1.523 g·cm-3, F(000) = 1012, μ = 1.038 mm~(-1), R = 0.0358 and w R2 = 0.0888(I 2σ(I)). Single-crystal X-ray diffraction analysis reveals that 1 is the first two-dimensional noninterpenetrating(4, 4) net coordination polymer based on the 2-thiobarbituric acid. Coordination polymer 1 exhibits two luminescent emission spectra at 477 and 489 nm with the excitation peak at 273 nm.     

Chromatographic and Spectroscopic Studies on β-Cyclodextrin Functionalized Ionic Liquid as Chiral Stationary Phase: Enantioseparation of Flavonoids

In this study, β-cyclodextrin functionalized ionic liquid was prepared by adding 1-benzylimidazole onto 6-monotosyl-6-deoxy-β-cyclodextrin (β-CDOTs) to obtain β-CD-BIMOTs. β-CD-BIMOTs were then bonded onto the modified silica to produce chiral stationary phases (β-CD-BIMOTs-CSP). The performance of β-CD-BIMOTs-CSP was evaluated by observing the enantioseparation of flavonoids. The performance of β-CD-BIMOTs stationary phase was also compared with native β-CD stationary phase. For the selected flavonoids, flavanone and hesperetin obtained a high resolution factor in reverse phase mode. Meanwhile, naringenin and eriodictyol attained partial enantioseparation in polar organic mode. In order to understand the mechanism of separation, the interaction of selected flavonoids and β-CD-BIMOTs was studied using spectroscopic methods (¹H NMR, NOESY and UV–Vis spectrophotometry). The enantioseparated flavanone and hesperetin were found to form an inclusion complex with β-CD-BIMOTs. However, naringenin and eriodictyol were not enantioseparated due to the formation of hydrogen bonding at exterior torus of β-CD-BIMOTs.

     

Synthesis and Characterization of a Novel 3D Coordination Polymer Based on Cu(Ⅱ) Cations and Mellitic Acid

A new mellitate complex [Cu3(μ2-mellitate)(μ2-H2O)(H2O)2·H2O]n 1 has been synthesi- zed by the reaction of mellitic acid and Cu(CH3COO)2·H2O in the presence of base. Crystallogra- phic data for 1: C12H80O16Cu3, Mr = 598.80, orthorhombic, Pbcn, a = 8.4378(6), b = 10.0396(7), c = 17.6799(12) A, V = 1497.70(18) A3, Z = 4, Dc = 2.656 g/cm3,μ = 4.327 mm-1, F(000) = 1180, R = 0.0431 and wR = 0.0964 for 1075 observed reflections (Ⅰ> 2σ(Ⅰ)). X-ray crystal structural analysis revealed that the mellitate anions behave as the bridging ligands and link eight copper atoms repeatedly to form a novel three-dimensional metal-organic coordination polymer with two different rhombic tunnels in the solid-state structure.     

Synthetic Studies on 1-Amino-1-Cyclopropane-Carboxylic Acid( Ⅰ )——The Cyclopropanation via Addition-Elimination Reactions

Various addition-elimination approaches have been explored for diastereoselective construction of 1-amino- 1-cyclopropane-carboxylic acid (ACPC) derivatives, and the desired product was obtained from a reaction of cyclo(NAc-L-Val-NAc-Gly) and methyl α-bro-moacrylate under protonic solvent.     

Synthesis,Crystal Structure and Antitumor Activity of a Na(Ⅰ) Coordination Polymer Based on 2-Propyl-4,5-imidazoledicarboxylic Acid and 1,10-Phenanthroline Ligands

A new Na(I) coordination polymer, [Na2(Hpimdc)(H2 pimdc)(phen)2]n(1), has been synthesized by the reaction of NaOH with 2-propyl-4,5-imidazoledicarboxylic acid(H3 pimdc)and 1,10-phenanthroline(phen). The Na(I) coordination polymer 1 was characterized by single-crystal X-ray diffraction analysis and elemental analysis. In 1, the bridged ligand H3 pimdc adopts two modes(singly deprotonated and doubly deprotonated) to coordinate with the Na(I) ion.The Na(1) ion is six-coordinated with three N atoms from a phen ligand and a H2 pimdc ligand,three O atoms from a Hpimdc ligand and two other different H2 pimdc ligands. The Na(2) ion is also six-coordinated with three N atoms from a phen ligand and a Hpimdc ligand, three O atoms from a H2 pimdc ligand and other two different Hpimdc ligands. Complex 1 exhibits a 1 D chain structure built up by μ-H2 pimdc-and μ-Hpimdc2-ligands. The antitumor activities of complex 1 against human SGC7901, A549 and H08910 cells have been tested.     

Studies on Polymer Chain Dimension in Solution——Calculation of Osmotic Pressures of Polymer Solutions

A modelr which has been developed to account for the effects of concentration on the chain dimensions of dissolved polymers has been combined with Zimm's statistical mechanical relation for the virial coefficients of dilute suspensions of hard spheres. The osmotic pressures (π/c) of 16 types of polymer/solvent calculated are in quite good accordance with experimental results from dilute to semi-dilute solutions and even concentrated solutions.In this procedure no adjustable parameters are needed except for the number average molecular weight of the sample and its intrinsic viscosity estimated from MarkHouwink coefficients.     

NMR Studies of a New Binding Mode of the Amino Acid Esters by Porphyrinatozinc(Ⅱ)

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Studies on Chromatography Fingerprint of Hongqi by High-performance Liquid Chromatography

Chromatography fingerprint (CFP) of 10 samples of hongqi were studied. 23 commonpeaks were analyzed, their average similarity was 97.29%. CFP were positioned with main indexcomposition such as formononetin, calycosin and then the contents of index composition weredetermined. The character and exclusive of CFP of 10 samples of hongqi were clear. CFP andcontent determination of index composition of hongqi could be used to evaluate the quality of hongqicomprehensively.     

Syntheses,Crystal Structure and Luminescent Properties of a Novel Mn(Ⅱ) Coordination Polymer Based on 1,3,5-Benzenetricarboxylic Acid

Coordination polymers are a novel class of crystalline materials, which have attracted a huge amount of interest in recent decades. We selected an organic ligand 1,3,5-benzenetricarboxylic acid(H_3 BTC) to assemble with Mn(Ⅱ) ions to construct a novel Mn(Ⅱ) coordination polymer crystal material(namely complex 1). The resultant sample was successfully synthesized under the solvothermal reaction. Complex 1 possesses a three-dimensional(3D) framework based on two different Mn(Ⅱ) clusters: [Mn_4(COO)_8] and [Mn_2(COO_4)]. Furthermore, the resultant sample can be characterized in detail by powder X-ray diffraction(PXRD), Fourier-transform infrared spectra(FT-IR), thermal gravimetric analyses(TGA), elemental analysis(C, H and N) and luminescence.