Synthesis, properties, and applications of urethane-modified acrylated poly(ester-amide)s

Epoxy resin-based unsaturated poly(ester-amide) resins (UPEAs) were treated with acryloyl chloride to afford acrylated UPEAs resins (AUPEAs). Urethane-based acrylated poly(ester-amide)s prepared by reaction with diisocyanate were characterized by elemental analysis, by molecular weight determination (by vapour pressure osmometry), by IR spectral study, and by thermogravimetry. The curing of interacting blends was monitored by differential scanning calorimetry (DSC). On the basis of DSC data in-situ glass-reinforced composites were prepared from the resulting materials and their mechanical, electrical, and chemical properties were characterized. Unreinforced blends were characterized by thermogravimetry.     

Sensitive Energetics from the N-Amination of 4-Nitro-1,2,3-Triazole

Energetic N-amino-C-nitro compounds 1-amino-4-nitro-1,2,3-triazole and 2-amino-4-nitro-1,2,3-triazole are characterized for the first time as energetic materials. These compounds were characterized chemically by nuclear magnetic resonance (NMR), Infrared spectroscopy and X-ray crystallography. Compounds were also characterized energetically by differential scanning calorimetry (DSC), impact, and friction and found to possess sensitivities and performances classifying them as primary explosives with PETN-like performance.     

Preparation of poly(glycidylmethacrylate‐divinylbenzene) weak acid cation exchange stationary phases with succinic anhydride,phthalic anhydride,and maleic anhydride for ion chromatography

In this work, poly(glycidylmethacrylate‐divinylbenzene) microspheres were prepared and applied for the preparation of weak acid cation exchange stationary phases. Succinic anhydride, phthalic anhydride, and maleic anhydride were selected as carboxylation reagents to prepare three weak acid cation exchangers by direct chemical derivatization reaction without solvent or catalyst. The diameters and dispersity of the microspheres were characterized by scanning electron microscopy; the amount of accessible epoxy groups and mechanical stability were also measured. The weak acid cation exchangers were characterized by Fourier transform infrared spectroscopy; the content of carboxyl groups was measured by traditional acid base titration method. The chromatographic properties were characterized and compared by separating alkali, alkaline earth metal ions and ammonium and polar amines. The separation properties enhanced in the order of succinic anhydride, phthalic anhydride, and maleic anhydride modified poly(glycidylmethacrylate‐divinylbenzene) cation exchangers.     

A thermally stable polybenzimidazole polybenzoxazole segmented block copolymer

m-phenyl benzoate end-capped pre-polybenzoxazole oligomer and a 3,4-diaminobenzene endcapped pre-polybenzimidazole were synthesized. These functionalized oligomers were then condensed to give a polybenzoxazole-polybenzimidazole segmented block copolymer. The functionalized oligomers were characterized by proton NMR, diffuse reflectance FTIR, and thermal gravimetric analysis. The final block copolymer was characterized by diffuse reflectance FTIR and thermal gravimetric analysis.     

Phospholipid bilayer formation on hydroxyapatite sol-gel synthesized films

Lipid bilayers supported by porous biomaterials are being explored as models for cell membranes. Hydroxyapatite is a relevant material currently being used extensively for biomedical applications. In this study, hydroxyapatite films produced via a sol-gel chemistry route have been characterized and explored as a scaffolding material for lipid membranes. The hydroxyapatite has been characterized using XRD, SEM, and AFM, followed by vesicle-fusion of lipids characterized by fluorescence microscopy and fluorescence recovery after photobleaching (FRAP) to determine the diffusion coefficient of this system. The HA films produced in this work were found to produce slow lateral diffusion and, in the two-phase lipid systems, some domains were observed. The low lateral diffusion coefficients were believed to be a result of the large undulations present on the hydroxyapatite film surface.     

Synthesis of vinyl-substituted beta-diketones for polymerizable metal complexes

[reaction: see text] Polymerizable beta-diketones for application to metal ion coordination have been prepared and characterized. Bromine-substituted beta-diketones were synthesized under Claisen-Schmidt-type condensation conditions. Vinyl groups were substituted for the halide by one of two types of Heck coupling with high-pressure ethylene. The type of Heck coupling employed was dictated by the thermal sensitivity of the substrate. Seven vinyl-substituted beta-diketones were synthesized, including several new ones, by this method. The beta-diketones were characterized by GC-MS, FT-NMR, FT-IR, and microanalysis.     

Random Poly(Lactic Acid-co-β-Alanine): Synthesis and Characterizations

A series of random polyesteramides (PEAs) within a range of molar composition from 90/10 to 10/90 were synthesized by a direct melt polycondensation of lactic acid and β-alanine. Their structures were fully characterized by NMR spectroscopy. The resulting copolymers are amorphous; they are thermally stable to temperatures up to 254°C, and present increasing glass transition temperatures at increasing amide content. The copolymers were also characterized by FTIR and viscosimetry measurements.     

Random Polyesteramides Based on Glycolic Acid and β-Alanine

A series of random polyesteramides (PEAs) within a range of molar composition from 90/10 to 10/90 were synthesized by a direct melt polycondensation of glycolic acid and β-alanine. Their structures were fully characterized by NMR spectroscopy. The resulting copolymers are amorphous and present increasing glass transition temperatures at increasing β-alanine contents. The copolymers were also characterized by, FTIR, TGA and viscosimetry measurements.     

Studies on novel interacting blends of acrylated poly(ester-amide)s having epoxy residues and vinyl ester of bisphenol-C

Novel unsaturated poly(ester-amide)s (UPEAs) were prepared by the reaction of Bisphenol-F based epoxy resin with bisamic acids. Acrylation of UPEAs were carried out using acryloyl chloride and the products are called Acrylated unsaturated poly(ester-amide)s (AUPEAs). These UPEAs were then treated with acrylol chloride to afford acrylated UPEAs resin (i.e., AUPEAs). Interacting blends of equal proportional AUPEAs and vinyl ester epoxy (VE) resin were prepared. APEAs and AUPEAs were characterized by elemental analysis, molecular weight determined by vapor pressure osmometer, IR spectral study and thermogravimetry. Curing of interacting blends was monitored on differential scanning calorimeter (DSC). Based on DSC data ‘in situ’ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA).     

Thermal behavior of vanadyl complexes with Schiff bases derived from trans-N,N′-bis(salicylidene)-1,2-cyclohexadiamine (t-Salcn)

Several Schiff bases coordinated to vanadyl, VO(Schiff base), were synthesized, characterized and studied by thermogravimetry in order to evaluate their thermal stability and thermal decomposition pathways. The number of steps and, in particular, the starting temperature of decomposition of these complexes depend on the equatorial ligand. The intermediates of the thermal decomposition processes were characterized by their IR spectra.     

Synthesis,characterization of novel interacting blends of acrylated poly(ester-amide)s containing epoxy residues with vinyl ester resin

Unsaturated bisamic acids were prepared by reaction between maleic anhydride and different aromatic diamines. Unsaturated poly(ester-amide) resin (UPEAs) was prepared by reaction of diglycidylether of bisphenol-A (DGEBA) with unsaturated bisamic acids. Acrylation of Unsaturated poly(ester-amide)s (UPEAs) was carried out to afford acrylated UPEAs resin (i.e., AUPEAs). Interacting blends of Acrylated unsaturated poly(ester-amide)s (AUPEAs) with vinyl ester epoxy (VE) resin were prepared. APEAs and AUPEAs were characterized by elemental analysis, molecular weight determined by vapor pressure osmometer and by IR spectral study and by thermogravimetry. The curing of interacting blends was monitored on differential scanning calorimeter (DSC). Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized thermo-gravimetrically (TGA).     

Preparation and properties of polyurethane networks based on α,ω-difunctional poly(hexafluoropropylene oxide)

Poly(hexafluoropropylene oxide), poly(HFPO), networks were prepared from functional polymers by end linking via urethane groups. The prepolymers were characterized by NMR spectroscopy and GPC. The networks were characterized by determination of the number of network chains from the shear modulus, and were snown to contain both trifunctional crosslinks and difunctional links. The properties of the networks were investigated by a range of techniques. Compared with fully-fluorinated networks formed via triazine cross-links, investigated previously, the urethane-linked networks were more readily prepared but were poorer elastomers, were less thermally stable, and were less resistant to swelling by common polar solvents. © 1995 John Wiley & Sons, Inc.     

Aliphatic polyesters. III. Molecular weight and molecular weight distribution in alcohol-initiated polymerizations of ϵ-caprolactone

The effect of initiation of ?-caprolactone polymerization with mono- and polyfunctional alcohols was investigated. The resulting linear and starshaped polymers were characterized by measurement of the molecular weight and molecular weight distribution. The polymerizations were characterized by (1) rapid initiation, (2) invariance of the number of growing chains corresponding to the amount of initiator, and (3) a dominant role played by ester interchange reactions.     

Epoxy-poly(2-ethylhexyl acrylate) interpenetrating polymer networks morphology and mechanical and thermal properties

Full and semi-IPNs of Poly(2-ethylhexyl acrylate), PEHA & crosslinked epoxy homopolymer were prepared and characterized by measurements of mechanical, thermal and morphological properties. Aromatic polyamine adducts and ethylene glycol dimethacrylate were used as the cross-linker for epoxy and comonomer/cross-linker for 2-ethyl hexyl acrylate monomer. Effects of changes of blend ratio on the properties were examined. Semi-IPNs were characterized by higher tensile strength and modulus than the corresponding full IPNs. Both semi- and full IPNs were characterized by broadening of transitions in their respective DSC curves while the weight retention in the thermal decomposition of the IPNs and pseudo-IPNs was higher than the epoxy homopolymer network. Phase separated rubber domains of various sizes are presumed to be responsible for the increased toughness of poly(2-ethyl hexyl acrylate)-modified epoxy which is substantiated by SEM micrographs.     

复合方式对MWCNTs/TiO2纳米复合薄膜光电化学性能的影响

采用溶胶-凝胶法制备了不同复合方式的系列多壁碳纳米管(multi-walled carbon nanotubes, MWCNTs)/TiO2纳米复合薄膜电极. 通过SEM表征了薄膜的表面形貌, 并测定了MWCNTs引入前后对TiO2晶型结构和光吸收性能的影响以及不同复合方式的纳米复合薄膜的光电化学特性. 结果表明, MWCNTs/TiO2纳米复合薄膜表面形成无序多孔的形貌, 其光谱吸收边可拓展到可见光区; MWCNTs底层分布的纳米复合薄膜比纯TiO2表现出更好的光电活性, 而MWCNTs在表层分布及均匀分布的纳米复合薄膜的光电活性相对较差. 依据载流子分离原理探讨了不同复合方式对纳米复合薄膜光电性能的影响, 底层分布MWCNTs的纳米复合薄膜由于MWCNTs有效地收集传递电子并阻止载流子的复合从而提高了光电化学活性.     

Synthesis of Poly（N-vinylpyrrolidone） Nanofibers Containing Gold Nanoparticles via Electrospinning Technique

Poly(N-vinylpyrrolidone)(PVP)nanofibers containing gold nanoparticles were prepared by electrospinning method.This simple route was used to prepare composites on a large scale,and the syntheses are simple.The optical property of gold nanoparticles in PVP aqueous solution was investigated by UV-Visible absorption spectra.The morphology of the fibers and the distribution of particles were characterized by transmission electron microscopy.The structure of the composite was characterized by Fourier transform infrared spectroscopy.     

Characterization of iron(III) oxide and oxide-hydroxide as Sr-sorbent

Iron(III) hydroxide and oxide-hydroxide samples prepared by precipitation of 0.2M iron(III) nitrate solution by 5M NaOH and subsequently aged at pH 12 for times of up to 50 h have been characterized. The sorption properties towards Sr²⁺ were characterized by radiotracer method using⁸⁵Sr, morphology of the samples was characterized by Transmission Electron Microscopy and Emanation Thermal Analysis. X-ray diffraction patterns characterized the crystallinity of the samples aged for various times. The maximum (100%) sorption capacity for⁸⁵Sr corresponding to amorphous iron(III) hydroxide decreased to 75% with the time of precipitate ageing (up to 40 h). This finding corresponds to the development in crystallinity and morphology of the sorbent.     

非水纳米分散系的冷冻蚀刻电镜表征及与激光散射法的对比研究

报道了利用改进的冷冻蚀刻制样技术对非水介质中原位合成的纳米分散系进行的电子显微镜表征结果。研究了冷冻蚀刻电镜技术观测原位合成纳米分散系的制样步骤、制样方法,并利用冷冻蚀刻电镜技术原位观测了3种纳米分散相的粒径、粒径分布和聚集状态。激光散射法与冷冻蚀刻电镜表征的对比表征结果表明：纳米分散系中纳米相的粒径和粒径分布用两种表征方法所得结果基本一致,但冷冻蚀刻电镜表征与激光散射法相比具有准确、直观、清晰、立体的特点,并且可同时采集多种信息。与激光散射法相比,是一种表征非水纳米分散系的理想方法。     

A Potentiometric and Spectroscopic Study on the Interaction Between Human Immunoglobulin G and Sodium Perfluorooctanoate in Aqueous Solution

The interaction between human immunoglobulin G (IgG) and sodium perfluorooctanate (SPFO) has been characterized by a combination of UV-vis and UV-CD spectroscopies and ion selective electrodes. The study determined that there were true specific unions between SPFO and IgG. The conformational changes at the bulk solution, induced by SPFO, were well characterized by UV-vis and UV-CD spectroscopies. Chemical and thermal unfolding were analysed and the thermodynamic parameters were determined.     

3-芳亚甲基联氨羰基-5-(对位取代苯基)-吡唑衍生物的 合成、结构和生物活性

以4-取代苯乙酮及草酸二乙酯为起始原料, 设计合成了20个新的3-芳亚甲基联氨羰基-5-(对位取代苯基)-吡唑衍生物, 产率较高. 所合成的化合物经元素分析, IR, 1H NMR对其结构进行了表征, 化合物4b, 4h还通过X-ray单晶衍射进一步确证了其结构. 初步生物活性实验结果表明, 所合成的化合物对绿豆发芽过程有着较好的生长调节作用.