Thermal Characterization of the Interaction of Silanes with a Dihydroxy Vulcanized Fluoroelastomer

2006 ◽  
Vol 79 (5) ◽  
pp. 765-782
Author(s):  
Michael Benjamin Sands ◽  
Vijay Subramanian ◽  
Guangzhao Mao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Vinylidene Fluoride ◽  
Thermal Characterization ◽  
Peak Shift ◽  
Amine Group ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Lower Temperature ◽  
Bisphenol Af

Abstract The reactivity of aminosilane and vinylsilane with a dihydroxy (Bisphenol AF) crosslinkable fluoroelastomer containing only vinylidene fluoride (VF2) and hexafluoropropylene (HFP) was monitored using Differential Scanning Calorimetry (DSC) and X-ray Photoelectron Spectroscopy (XPS). The DSC results showed that the introduction of an aminosilane, or a combination of aminosilane and vinylsilane solutions, to the cure system of the fluoroelastomer resulted in a peak shift. This shift indicates that crosslinking in fluoroelastomer-silane system occurs at a lower temperature when aminosilane is present. Results also confirm that the organofunctional group on the silane reacts with the elastomer. XPS analysis of the silane-coated fluoroelastomer heated at 120 °C, 160 °C and 200 °C reveals that dehydrofluorination of the polymer is one of the steps in the reaction. It is our hypothesis that the amine group on the aminosilane is a contributor to the dehydrofluorination of the fluoroelastomer.

scholarly journals Effect of the Degree of Substitution on the Hydrophobicity, Crystallinity, and Thermal Properties of Lauroylated Amaranth Starch

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2548
Author(s):  
Vicente Espinosa-Solis ◽  
Yunia Verónica García-Tejeda ◽  
Everth Jimena Leal-Castañeda ◽  
Víctor Barrera-Figueroa
Keyword(s):  
Photoelectron Spectroscopy ◽  
Thermal Characterization ◽  
Fatty Acyl ◽  
Degree Of Substitution ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Amaranthus Hypochondriacus ◽  
Two Samples ◽  
Acyl Chains

In this paper, we consider amaranth starch extracted from the seeds of Amaranthus hypochondriacus L. An amphiphilic character is conferred to the starch by a chemical modification, which involves an esterification by lauroyl chloride at three modification levels. The degree of substitution (DS) after the modification ranged from 0.06 to 1.16. X-ray photoelectron spectroscopy analysis confirmed the presence of fatty acyl chains on the surface of the esterified starches. The hydrophobicity of starches was confirmed by their adsorption isotherms, which showed a decrease in the moisture adsorption of lauroylated as DS increased. X-ray diffraction analysis revealed a higher crystallinity, which was observed in the two samples subjected to the highest levels of modification. A higher crystallinity is related to a higher gelatinization enthalpy. These results are in agreement with the thermal characterization obtained by differential scanning calorimetry (DSC). An inhibition of the retrogradation properties of lauroylated amaranth starches was also observed.

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.

Sputter-deposition and characterization of paramelaconite

2003 ◽  
Vol 18 (7) ◽  
pp. 1535-1542 ◽  
Author(s):  
K. J. Blobaum ◽  
D. Van Heerden ◽  
A. J. Wagner ◽  
D. H. Fairbrother ◽  
T. P. Weihs
Keyword(s):  
Photoelectron Spectroscopy ◽  
Metastable Phase ◽  
Heat Of Formation ◽  
Sputter Deposition ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multilayer Foils ◽  
Out Of Plane ◽  
Processing Techniques

While processing techniques for deposition of CuOx/Al multilayer foils were being developed, a method for synthesizing paramelaconite (Cu4O3) was serendipitously discovered. These paramelaconite films were successfully synthesized by sputter-deposition from a CuO target. Milligram quantities of uncontaminated material were produced enabling new studies of the morphology, stoichiometry, and thermodynamics of this unique copper oxide. At moderate temperatures, equiaxed paramelaconite grains deposited with a strong out-of-plane texture; at lower temperatures the paramelaconite grains showed no texture but were columnar in geometry. X-ray photoelectron spectroscopy showed that the as-deposited Cu4O3 had a nonstoichiometric Cu:O ratio of 1.7:1; the ratio of Cu+ to Cu2+ was 1.8:1. On heating, this phase decomposed into CuO and Cu2O at temperatures ranging from 400 to 530 °C. Using differential scanning calorimetry, the heat of formation and Gibbs free energy for Cu4O3 were estimated to be −453 and −279 kJ/mol, respectively. On the basis of these calculations and our observations, we confirmed that Cu4O3 is a metastable phase.

Synthesis and Characterization of a POSS-Urethane Hybrid Coating for Use in the Corrosion Protection of Metal

2005 ◽  
Vol 23 ◽  
pp. 231-234 ◽  
Author(s):  
Matthew Oaten ◽  
Namita Roy Choudhury
Keyword(s):  
Corrosion Protection ◽  
Photoelectron Spectroscopy ◽  
Hybrid Coating ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Clean Steel ◽  
X Ray ◽  
Oligomeric Silsesquioxane ◽  
Steel Substrates

The potential of cyclic silsesquioxanes as flexible coatings has been explored in this work for corrosion protection of metal. A polyurethane coating containing an inorganic polyhedral oligomeric silsesquioxane (POSS) was synthesized and characterized by means of photo-acoustic infrared spectroscopy, X-ray photoelectron spectroscopy (XPS), contact angle and modulated differential scanning calorimetry (MDSC). The coating has been applied to clean steel substrates via dip and spin coating. The POSS based hybrid coating is found to be uniform, dense and essentially defect free. XPS shows that the coating forms a lamellar layered structure on the substrate.

Chemical synthesis and characterization of polyaniline-molybdenum trisulfide composite

1999 ◽  
Vol 14 (5) ◽  
pp. 1805-1813 ◽  
Author(s):  
Florence Fusalba ◽  
Daniel Bélanger
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Synthesis And Characterization ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Chemical Polymerization ◽  
X Ray ◽  
Scanning Electron

A novel polyaniline-molybdenum trisulfide composite has been prepared by chemical polymerization from an acidic (1 M HCl) aqueous solution containing aniline and ammonium tetrathiomolybdate. The presence of molybdenum trisulfide in the polyaniline matrix induces morphological change to the polymer as evidenced by scanning electron micrographs. X-ray diffraction and differential scanning calorimetry indicate that polyaniline-molybdenum trisulfide is slightly less crystalline than polyaniline-HCl. X-ray photoelectron spectroscopy (XPS) and elemental analysis have been used to confirm the presence of molybdenum trisulfide in the polymer matrix. The XPS data also confirm that molybdenum trisulfide and tetrathiomolybdate anions are present with polyaniline to form a new inorganic-organic composite.

scholarly journals Chemical and thermal characterization of the construction material of nests of seven species of wasps from Norte de Santander - Colombia.

Respuestas ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 27-38
Author(s):  
María Del Carmen Parra Hernández ◽  
Diana Alexandra Torres Sánchez
Keyword(s):  
Thermogravimetric Analysis ◽  
Construction Material ◽  
Fluorescence Analysis ◽  
Thermal Characterization ◽  
Moisture Loss ◽  
Infrared Analysis ◽  
Scanning Calorimetry ◽  
Characteristic Functional ◽  
X Ray

Social wasps are insects that construct their nests using wood pulp, plant and themselves secretions for the accomplishment of their activities as a colony. Currently in Colombia, there is little knowledge about this interesting material due to its characteristics, which could be used in promising applications. In this work the chemical and thermal characterization of nests of seven species of wasps (Agelaia pallipes, Agelaia multipicta, Agelaia areata, Polybia aequatorialis, Parachartergus apicalis, Mischucytharus imitator, Brachygastra lecheguana) living in Norte de Santander, was carried out with the purpose of establishing if there are significant differences between species and provide information that could be used as a model or precursors for the synthesis in biomimetics and / or nanotechnology. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were performed using a Thermal analyser SDT-Q600 from T.A. Instruments. An infrared spectrophotometer FT-IR SHIMADZU Prestige-21 with ATR was used for infrared analysis. The fluorescence analysis (XRF) was performed using a sequential X-ray fluorescence spectrometer of dispersive wavelength of 4kW BRUKER model S8 TIGER. The thermogravimetric analysis shows three mass losses and four degradation processes related to moisture loss, degradation of hemicellulose, cellulose and lignin. The infrared analysis allowed identifying characteristic functional groups of cellulose, hemicellulose and lignin. Through the X-ray fluorescence analysis, some metals such as K, Ca, Al, Mg, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Se and Li were found. The analyses made of the samples allowed to establish differences and similarities in the construction material of the studied species.

Preparation and Characterization of APTES Modified Bioglass

2008 ◽  
Vol 368-372 ◽  
pp. 1215-1217
Author(s):  
Li Ren ◽  
Tian Yi Yang ◽  
Ying Gang Zhao ◽  
Na Ru Zhao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Structures ◽  
Polymer Materials ◽  
Attenuated Total Reflectance ◽  
Scanning Calorimetry ◽  
Total Reflectance ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Sbf Solution

Bioglass (BG) particles were treated by 3-aminopropyltriethoxysilane (APTES) in order to improve the interface compatibility with polymer materials. The surface structures of modified BG were characterized through Fourier transformed infrared spectroscopy with attenuated total reflectance accessory, thermogravimetric analysis, differential scanning calorimetry analysis and X-ray photoelectron spectroscopy. The results showed that APTES was successfully grafted on the surface of BG. The biomineralization properties of APTES modified bioglass were also studied through FTIR, XRD and SEM. Results showed that hydroxylcarbonateapatite (HCA) was formed on the surface of modified BG after soaked into SBF solution. It was shown that the APTES modified BG could possess good mineralization properties and could be intended as a composition of scaffolds for bone tissue engineering applications.

Low-Temperature Synthesis and Characterization of Single-Phase BiFeO3 Nano-Crystallites

2012 ◽  
Vol 164 ◽  
pp. 115-119
Author(s):  
Hui Fen Guo ◽  
Shu Xia Guo ◽  
Li Ben Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Single Phase ◽  
Crystallization Process ◽  
Exothermic Peak ◽  
Scanning Calorimetry ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
X Ray ◽  
Intermediate Phases

Single-phase BiFeO3 (BFO) nano-crystallites were successfully synthesized in the temperature range of 500  750 oC by a simple diluted HNO3 sol method. During the crystallization process no intermediate phases were observed. As an example, we studied the electronic structure and thermodynamic stability of the BFO nano-crystallites calcined at 750 oC by X-ray photoelectron spectroscopy (XPS) and differential scanning calorimetry (DSC). The XPS showed that the oxidation state of Fe is Fe3+. The DSC indicated a novel exothermic peak at about 769 oC during cooling, which might be due to Bi2Fe4O9 or some other phases produced in the decomposition of BFO at high temperature.

scholarly journals Thermal characterization of partially hydrolyzed cassava (Manihot esculenta) starch granules

2008 ◽  
Vol 51 (6) ◽  
pp. 1209-1215 ◽  
Author(s):  
Luiz Gustavo Lacerda ◽  
Jayme Augusto Menegassi Azevedo ◽  
Marco Aurélio da Silva Carvalho Filho ◽  
Ivo Mottin Demiate ◽  
Egon Schnitzler ◽  
...  
Keyword(s):  
Thermal Characterization ◽  
Cassava Starch ◽  
Starch Granules ◽  
Gelatinization Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Similar Range ◽  
Partial Degradation

Cassava starch, partially hydrolyzed by fungal á-amylase, was characterized using thermal analysis, light microscopy and X-ray diffraction. Thermal degradation was initiated at lower degradation temperatures after enzymatic treatment and the DSC (Differential scanning calorimetry) analysis showed almost similar range of gelatinization temperature, but the enthalpies of gelatinization were quite increased for the partially hydrolyzed starch granules. The results suggested that the partial degradation of the starch granules was concentrated in the amorphous regions.

Preparation and characterization of conducting nylon 6 fibers

2009 ◽  
Vol 24 (8) ◽  
pp. 2728-2735 ◽  
Author(s):  
A. Saritha Chandran ◽  
Sunil K. Narayanankutty
Keyword(s):  
Photoelectron Spectroscopy ◽  
In Situ Polymerization ◽  
Fiber Surface ◽  
Nylon 6 ◽  
Etching Time ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

Conducting nylon 6 fibers were prepared by in situ polymerization of aniline on to the fiber surface, after providing a chemical etching treatment to the fibers using chromic acid. The properties of the etched and polyaniline (PANI) coated fibers were evaluated using scanning electron microscopy, x-ray photoelectron spectroscopy, infrared spectroscopy, x-ray diffraction, thermogravimetry, and differential scanning calorimetry. Though the etching process caused a marginal decline in the mechanical properties of the fiber, it provided a reasonably rough surface for PANI adhesion and enhanced the conductivity of the fiber. The conductivity increased from 4.22 × 10−2 to 3.72 × 10−1 S/cm at an etching time of 4 h.

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