Synthesis and Characterization of New Polyurethane Adhesives

2006 ◽  
Vol 514-516 ◽  
pp. 843-847 ◽  
Author(s):  
Cristina Borges Correia ◽  
João C. Bordado
Keyword(s):  
Raw Materials ◽  
Impact Resistance ◽  
Inert Atmosphere ◽  
Stray Field ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Polyurethane Adhesives ◽  
Dimer Acids

Polyurethane adhesives provide excellent flexibility, impact resistance and durability. Polyurethanes are formed through the reaction of an isocyanate component with polyether or polyester polyols or other active hydrogen compounds. This paper refers to polyurethane adhesives made from polyester polyols with long aliphatic chains (up to 36 carbon atoms) and MDI (diphenylmethane-4,4’-diisocyanate). The polyester polyols have been made from dimer acids obtained from renewable sources and short chain diols. The polyols that were used presented different degrees of unsaturation. The influence of the different raw materials in the adhesives performance is studied. The polyurethanes were produced by reaction between quasi-stoichiometric quantities of polyol and MDI, at several temperatures. The reaction was carried under inert atmosphere and at temperatures below 100°C. Performance of the adhesives was tested by carrying adhesion, hardness and water absorption tests. Characterization of both the polyester polyols and polyurethane adhesives was carried by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Magnetic Nuclear Resonance (NMR), X-Ray Diffraction (WAXD), Scanning RMN Imaging of 1H of Stray- Field b (MRI) and Brookfield viscometry.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

Synthesis of Spherical LiFePO4/C Composites as Cathode Material of Lithium-Ion Batteries by a Novel Glucose Assisted Hydrothermal Method

2013 ◽  
Vol 787 ◽  
pp. 58-64 ◽  
Author(s):  
Xiang Feng Li ◽  
Zhao Zhang ◽  
Fang Liu ◽  
Shu Ping Zheng
Keyword(s):  
Hydrothermal Method ◽  
Raw Materials ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
High Discharge ◽  
X Ray ◽  
High Discharge Capacity ◽  
Optimal Sample ◽  
Structure Morphology

The LiFePO4/C composites with different morphology are synthesized by a novel glucose assisted hydrothermal method at various glucose concentrations (from 0 to 0.25mol/L) and the insoluble lithium source Li2CO3, (NH4)2Fe (SO4)2·6H2O and (NH4)2HPO4(n (Li):n (Fe):n (P)=1:1:1) are used as raw materials. The structure, morphology, thermal performance and electrochemical properties of the synthesized composites are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetry/differential scanning calorimetry (TG-DSC), galvanostatic charge/discharge tests and cyclic voltammetry (CV). The results show that the LiFePO4/C synthesized with 0.125mol/L glucose has the relatively small particles size (0.1~0.5μm) and the well spherical morphology. The optimal sample exhibits a high discharge capacity of 160.0mAh/g at the first cycle and exhibits a good reversibility and stability in CV tests.

Characterization of New Nonstoichiometric Ferroelectric (Li0.95Cu0.15)Ta0.76Nb0.19O3 and Comparative Study With (Li0.95Cu0.15)Ta0.57Nb0.38O3 as Photocatalysts in Microbial Fuel Cells

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
S. Louki ◽  
N. Touach ◽  
A. Benzaouak ◽  
V. M. Ortiz-Martínez ◽  
M. J. Salar-García ◽  
...  
Keyword(s):  
Power Density ◽  
Microbial Fuel Cells ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Ferroelectric Material ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Uv Visible

This work investigates the photocatalytic activity of new ferroelectric material with formula (Li0.95Cu0.15)Ta0.76Nb0.19O3 (LT76) in a single chamber microbial fuel cell (MFC) and compares its performance with the similar photocatalyst (Li0.95Cu0.15)Ta0.57Nb0.38O3 (LT57). The photocatalysts LT76 and LT57 were synthesized by ceramic route under the same conditions, with the same starting materials. The ratio Ta/Nb was fixed at 4.0 and 1.5 for LT76 and LT57, respectively. These phases were characterized by different techniques including X-ray diffraction (XRD), transmission electronic microscopy (TEM), particle size distribution (PSD), differential scanning calorimetry (DSC), and ultraviolet (UV)–visible (Vis). The new photocatalyst LT76 presents specific surface area of 0.791 m2/g and Curie temperature of 1197 °C. The photocatalytic efficiency of this material is assessed in terms of wastewater treatment and electricity generation by power density and removal rate of chemical oxygen demand (COD) in the presence of a light source. The values of maximum power density and COD removal were 19.77 mW/m3 and 93%, respectively, for LT76.

scholarly journals Stacking Control by Molecular Symmetry of Sterically Protected Phthalocyanines

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5552
Author(s):  
Ryota Kudo ◽  
Masahiro Sonobe ◽  
Yoshiaki Chino ◽  
Yu Kitazawa ◽  
Mutsumi Kimura
Keyword(s):  
Lamellar Structure ◽  
Synthesis And Characterization ◽  
Molecular Symmetry ◽  
X Ray Diffraction ◽  
Melting Points ◽  
Scanning Calorimetry ◽  
Structural Isomers ◽  
X Ray ◽  
Temperature Controlled

The synthesis and characterization of two phthalocyanine (Pc) structural isomers, 1 and 2, in which four 2,6-di(hexyloxy)phenyl units were attached directly to the 1,8,15,22- or 1,4,15,18-positions of the Pc rings, are described. Both Pcs 1 and 2 exhibited low melting points, i.e., 120 and 130 °C respectively, due to the reduction in intermolecular π-π interaction among the Pc rings caused by the steric hindrance of 2,6-dihexyloxybenzene units. The thermal behaviors were investigated with temperature-controlled polarizing optical microscopy, differential scanning calorimetry, powder X-ray diffraction, and absorption spectral analyses. Pc 1, having C4h molecular symmetry, organized into a lamellar structure containing lateral assemblies of Pc rings. In contrast, the other Pc 2 revealed the formation of metastable crystalline phases, including disordered stacks of Pcs due to rapid cooling from a melted liquid.

scholarly journals Characterization of the Interface Between the Bulk Glass Forming Alloy Zr41Ti14Cu12Ni10Be23 with Pure Metals and Ceramics

2000 ◽  
Vol 15 (7) ◽  
pp. 1617-1621 ◽  
Author(s):  
Jan Schroers ◽  
Konrad Samwer ◽  
Frigyes Szuecs ◽  
William L. Johnson
Keyword(s):  
Sessile Drop ◽  
Bulk Glass ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glass Forming ◽  
Processing Times ◽  
Thermal Stability Of

The reaction of the bulk glass forming alloy Zr41Ti14Cu12Ni10Be23 (Vit 1) with W, Ta, Mo, AlN, Al2O3, Si, graphite, and amorphous carbon was investigated. Vit 1 samples were melted and subsequently solidified after different processing times on discs of the different materials. Sessile drop examinations of the macroscopic wetting of Vit 1 on the discs as a function of temperature were carried out in situ with a digital optical camera. The reactions at the interfaces between the Vit 1 sample and the different disc materials were investigated with an electron microprobe. The structure and thermal stability of the processed Vit 1 samples were examined by x-ray diffraction and differential scanning calorimetry. The results are discussed in terms of possible applications for composite materials.

scholarly journals Synthesis and Crystal Structure of the Bioinorganic Complex [Sb(Hedta)]·2H2O

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Di Li ◽  
Guo-Qing Zhong
Keyword(s):  
Crystal Structure ◽  
Ethylenediaminetetraacetic Acid ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Cell Parameters ◽  
Composition And Structure ◽  
Decomposition Processes ◽  
Distorted Trigonal Bipyramid

The antimony(III) complex [Sb(Hedta)]·2H2O was synthesized with ethylenediaminetetraacetic acid (H4edta) and antimonous oxide as main raw materials in aqueous solution. The composition and structure of the complex were characterized by elemental analysis, infrared spectra, single crystal X-ray diffraction, X-ray powder diffraction, thermogravimetry, and differential scanning calorimetry. The crystal structure of the antimony(III) complex belongs to orthorhombic system, space group Pna2(1), with cell parameters ofa=18.4823(18) Å,b=10.9408(12) Å,c=7.3671(5) Å,V=1489.7(2) Å3,Z=4, andDc=1.993 g cm−3. The Sb(III) ion is five-coordinated by two amido N atoms and three carboxyl O atoms from a single Hedta3−ligand, forming a distorted trigonal bipyramid geometry. The thermal decomposition processes of the complex include dehydration, oxidation, and pyrolysis of the ligand, and the last residue is Sb2O3at the temperature of 570°C.

The Synthesis and Characterization of Oxide Free Tin Nanoparticles

2014 ◽  
Vol 670-671 ◽  
pp. 26-29
Author(s):  
Zhi Long Pan ◽  
Shi Liang Ao ◽  
Jian Ping Jia
Keyword(s):  
Reduction Method ◽  
Chemical Reduction ◽  
Thermal Characterization ◽  
X Ray Diffraction ◽  
Chemical Reduction Method ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Xrd Study ◽  
Tin Nanoparticles

Oxide free Tin nanoparticles were synthesized from a chemical reduction method. Their morphological and thermal characterizations were studied in this paper. The X-ray diffraction (XRD) study showed that no oxides of Tin nanoparticles were formed. The thermal characterization by differential scanning calorimetry (DSC) exhibited the size dependency of the melting points. The melting point was as low as 202.16°C.

Preparation and Characterization of PCL/PVP Blend Membrane

2011 ◽  
Vol 311-313 ◽  
pp. 1638-1641
Author(s):  
Jun Hua Wang ◽  
Xiang Biao Cheng ◽  
Gang Huang ◽  
Feng Chun Dong ◽  
Yong Tang Jia
Keyword(s):  
Mechanical Property ◽  
Membrane Structure ◽  
Solution Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Blend Membrane ◽  
X Ray ◽  
Structure And Morphology ◽  
Xrd Techniques

PCL/PVP blend membrane was prepared by casting solution method. Scanning electron microscopy (SEM), diffraction scanning calorimetry (DSC), and X-ray diffraction (XRD) techniques were employed to characterize membrane structure and morphology. Moreover, the hydrophilicity, mechanical property and biodegradability of membranes were investigated. Due to introducing PVP, the crystallinity and mechanical property of PCL altered to some extent. The hydrophilicity of the blend membrane improved remarkably with increasing PVP content, which was expressed by the contact angle declining and the rate of water absorption increasing. Lipase accelerated the degradation rate of PCL/PVP membrane.

scholarly journals Effects of Chlorinated Polypropylene on the Conformation of Polypropylene in Polypropylene/Chlorinated Polypropylene/Polyaniline Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jianjun Chen ◽  
Yueyue Jia ◽  
Zhiye Zhang ◽  
Xinlong Wang ◽  
Lin Yang
Keyword(s):  
Intensity Ratio ◽  
Maximum Level ◽  
In Situ Ftir ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Infrared Band ◽  
X Ray ◽  
Polyaniline Composites

We investigated the changes in the conformation and crystalline structure of polypropylene (PP) using a combination of Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD), and differential scanning calorimetry (DSC) based on PP/chlorinated PP (CPP)/polyaniline (PANI) composites. The DSC heating thermograms and WAXD patterns of the PP/CPP/PANI composites showed that theβ-crystal was affected greatly by the CPP content. Characterization of the specific regularity in the infrared band variation showed that the conformational orders of the helical sequences in PP exhibited major changes that depended on the CPP content. Initially, the intensity ratio ofA840/A810increased with the CPP concentration and reached its maximum level when the CPP content was <13.22% before decreasing as the CPP content increased further. The effect of increased temperature on the conformation of PP was studied by in situ FTIR. Initially, the intensity ratio ofA999/A973decreased slowly with increasing the temperature up to 105°C before decreasing sharply with further increases in temperature and then decreasing slowly again when the temperature was higher than 128°C.

Characterization of Nanocrystalline γ–Fe2O3Prepared by Wet Chemical Method

1999 ◽  
Vol 14 (4) ◽  
pp. 1570-1575 ◽  
Author(s):  
G. Ennas ◽  
G. Marongiu ◽  
A. Musinu ◽  
A. Falqui ◽  
P. Ballirano ◽  
...  
Keyword(s):  
Isothermal Treatment ◽  
X Ray Diffraction ◽  
Ferrous Chloride ◽  
Scanning Calorimetry ◽  
Direct Transformation ◽  
X Ray ◽  
Transmission Electron ◽  
Xrd Techniques ◽  
Kinetics Of

Homogeneous maghemite (γ–Fe2O3) nanoparticles with an average crystal size around 5 nm were synthesized by successive hydrolysis, oxidation, and dehydration of tetrapyridino-ferrous chloride. Morphological, thermal, and structural properties were investigated by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and x-ray diffraction (XRD) techniques. Rietveld refinement indicated a cubic cell. The superstructure reflections, related to the ordering of cation lattice vacancies, were not detected in the diffraction pattern. Kinetics of the solid-state phase transition of nanocrystalline maghemite to hematite (α–Fe2O3), investigated by energy dispersive x-ray diffraction (EDXRD), indicates that direct transformation from nanocrystalline maghemite to microcrystalline hematite takes place during isothermal treatment at 385 °C. This temperature is lower than that observed both for microcrystalline maghemite and for nanocrystalline maghemite supported on silica.

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