Comparative Studies on Photoelasticity of Elastomers and Plastomers

Abstract Transparent films of elastomers and plastomers were found to differ sufficiently in their photoelastic behavior to make stress double refraction a useful criterion of the prospective mechanical properties of a given material. The stress double refraction in such films is mostly an effect of deformation, of orientation, or of both deformation and orientation of polymer chains. In such polymers, however, which crystallize under stress, a large part of the optical effect may be due to oriented crystallization. In addition to its practical value as a testing method for polymers, the photoelastic method offers, therefore, particularly in combination with simultaneous investigations of mechanical properties, the prospect of correlating mechanical properties of a polymer film with its internal structure, and of correlating changes in both qualities on exposure of the film to different degrees of stress. Although results obtained on such films, by means of x-ray diffraction or x-ray scattering and electron-diffraction, are, in general, easier to interpret, the photoelastic method has the considerable advantage of making possible a quantitative follow-up of rapid changes in film structure, e.g., of relaxations.

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Copper Containing Glass-Based Bone Adhesives for Orthopaedic Applications: Glass Characterization and Advanced Mechanical Evaluation

10.1101/2020.11.19.390138 ◽

2020 ◽

Author(s):

Sahar. Mokhtari ◽

Anthony.W. Wren

Keyword(s):

Mechanical Properties ◽

Photoelectron Spectroscopy ◽

Structural Changes ◽

Viscoelastic Behavior ◽

Polymer Chains ◽

Nano Particles ◽

X Ray Diffraction ◽

X Ray ◽

Compression Data

AbstractThis study addresses issues with currently used bone adhesives, by producing novel glass based skeletal adhesives through modification of the base glass composition to include copper (Cu) and by characterizing each glass with respect to structural changes. Bioactive glasses have found applications in fields such as orthopedics and dentistry, where they have been utilized for the restoration of bone and teeth. The present work outlines the formation of flexible organic-inorganic polyacrylic acid (PAA) – glass hybrids, commercial forms are known as glass ionomer cements (GICs). Initial stages of this research will involve characterization of the Cu-glasses, significant to evaluate the properties of the resulting adhesives. Scanning electron microscopy (SEM) of annealed Cu glasses indicates the presence of partial crystallization in the glass. The structural analysis of the glass using Raman suggests the formation of CuO nanocrystals on the surface. X-ray diffraction (XRD) pattern and X-ray photoelectron spectroscopy (XPS) further confirmed the formation of crystalline CuO phases on the surface of the annealed Cu-glass. The setting reaction was studied using Fourier transform infrared spectroscopy (ATR-FTIR). The mechanical properties of the Cu containing adhesives exhibited gel viscoelastic behavior and enhanced mechanical properties when compared to the control composition. Compression data indicated the Cu glass adhesives were efficient at energy dissipation due to the reversible interactions between CuO nano particles and PAA polymer chains.

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Some Attempts to Force Poly(Dimethylsiloxane) Chains through Zeolite Cavities to Improve Elastomer Reinforcement

Rubber Chemistry and Technology ◽

10.5254/1.3538783 ◽

1999 ◽

Vol 72 (1) ◽

pp. 138-151 ◽

Cited By ~ 5

Author(s):

Zhengcai Pu ◽

James E. Mark ◽

Gregory Beaucage

Keyword(s):

Mechanical Properties ◽

Polymer Chains ◽

Synthetic Approach ◽

Cavity Size ◽

Strain Measurements ◽

X Ray ◽

X Ray Scattering ◽

Pdms Elastomer ◽

Equilibrium Swelling ◽

Reinforcing Effects

Abstract The reinforcing effects of zeolites in poly(dimethylsiloxane) (PDMS) elastomers were characterized using two preparative approaches. In the first, end-functionalized polymer chains were blended into the zeolite, and were then endlinked into the required network structure. The second approach represented an attempt to force some chains through the cavities, by blending the monomer itself into the zeolite and then polymerizing it to obtain the PDMS elastomer. The two types of zeolite-filled PDMS were characterized using stress-strain measurements in elongation, equilibrium swelling, and small-angle X-ray scattering. The second synthetic approach did seem to give improvements in mechanical properties, particularly when the average cavity size of the zeolite particles was relatively large. Ascribing the observed improvements in reinforcement at least partly to the threading of some PDMS chains through the zeolites was supported by the results obtained in the swelling and scattering experiments.

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Spectroscopic evidence of successful in situ insertion of sol–gel silica in a poly(3-hydroxybutyrate) matrix

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705720935939 ◽

2020 ◽

pp. 089270572093593

Author(s):

Anna Lecticia Martinez Martinez Toledo ◽

Elton Jorge da Rocha Rodrigues ◽

Maxwell de Paula Cavalcante ◽

José Carlos Dutra Filho ◽

Maria Inês Bruno Tavares

Keyword(s):

Sol Gel ◽

Polymer Chains ◽

Nonlinear Dependence ◽

X Ray Diffraction ◽

Crystallinity Degree ◽

X Ray ◽

X Ray Scattering ◽

Different Levels ◽

Inorganic Structure

Silica-based (SiO2) poly(3-hydroxybutyrate) (PHB) nanocomposites were obtained via an in situ sol–gel route in three distinct particle concentrations (1, 5, and 7.5% by weight of PHB). The polymer hybrids formed were analyzed via wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), Fourier transform infrared (FTIR) spectroscopy, and time-domain nuclear magnetic resonance relaxometry (TD-NMR). The SiO2 inorganic structure displayed surface fractal features at low concentration (1 wt%) and denser agglomerates at higher concentrations (5 and 7.5 wt%). FTIR and SAXS results confirmed the formation of the inorganic matrix amid the polymer chains with different levels of distribution and organization. WAXD and TD-NMR results suggested the SiO2 influence on the PHB crystallinity degree, which was reflected on the polymer’s molecular dynamics with a nonlinear dependence of particles concentration in the PHB matrix.

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Self-assembled Materials Containing Complementary Nucleobase Molecular Recognition

MRS Proceedings ◽

10.1557/proc-1094-dd06-05 ◽

2008 ◽

Vol 1094 ◽

Cited By ~ 1

Author(s):

Wirasak Smitthipong ◽

Arkadiusz Chworos ◽

Brian Lin ◽

Thorsten Neumann ◽

Surekha Gajria ◽

...

Keyword(s):

Molecular Structure ◽

Mechanical Properties ◽

Nucleic Acid ◽

Nucleic Acids ◽

X Ray ◽

Transparent Films ◽

X Ray Scattering ◽

Counter Ions ◽

Self Assembled ◽

Cationic Amphiphile

AbstractHere we report the nucleic acid/cationic amphiphile based-materials in which we exchange the counter-ions of the polyanionic backbone of the nucleic acids with the cationic amphiphiles to form self-assembled transparent films with the thickness of several microns. Predominantly, single stranded poly(A), poly(U) and double stranded poly(AU) were employed for these studies. Small-angle X-ray scattering (SAXS) experiments suggested lamellar-like structure for all the film samples. However, the molecule length as well as the molecular structure of nucleic acids can affect the topology and mechanical properties of these films. Complementary base-paring of poly(AU) is reported here with comparison to poly(A) and poly(U) complexes.

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Electron Microscopy of Human Gallstones

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065523 ◽

1971 ◽

Vol 29 ◽

pp. 296-297

Author(s):

C. Wolpers ◽

R. Blaschke

Keyword(s):

Electron Microscopy ◽

Room Temperature ◽

Bile Pigment ◽

X Ray Diffraction ◽

Triclinic Crystal System ◽

X Ray ◽

Follow Up Study ◽

Infra Red ◽

Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

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Mechanical properties of FeAlSi powders prepared by mechanical alloying from different initial feedstock materials

Matériaux & Techniques ◽

10.1051/mattech/2018063 ◽

2019 ◽

Vol 107 (2) ◽

pp. 207 ◽

Cited By ~ 2

Author(s):

Jaroslav Čech ◽

Petr Haušild ◽

Miroslav Karlík ◽

Veronika Kadlecová ◽

Jiří Čapek ◽

...

Keyword(s):

Mechanical Properties ◽

Mechanical Alloying ◽

Young’S Modulus ◽

Milling Time ◽

Young's Modulus ◽

Element Model ◽

X Ray Diffraction ◽

X Ray ◽

Powder Particles ◽

Complete Homogenization

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.

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New Structure of CTAB Templated Silica Films as revealed by GISAXS coupled to HRTEM

MRS Proceedings ◽

10.1557/proc-628-cc8.3 ◽

2000 ◽

Vol 628 ◽

Author(s):

Sophie Besson ◽

Catherine Jacquiod ◽

Thierry Gacoin ◽

André Naudon ◽

Christian Ricolleau ◽

...

Keyword(s):

Cetyltrimethylammonium Bromide ◽

Grazing Incidence ◽

Hexagonal Structure ◽

X Ray Diffraction ◽

Electronic Microscopy ◽

Silica Films ◽

X Ray ◽

X Ray Scattering ◽

Hexagonal Arrangement ◽

Spherical Micelles

ABSTRACTA microstructural study on surfactant templated silica films is performed by coupling traditional X-Ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM) to Grazing Incidence Small Angle X-Ray Scattering (GISAXS). By this method it is shown that spin-coating of silicate solutions with cationic surfactant cetyltrimethylammonium bromide (CTAB) as a templating agent provides 3D hexagonal structure (space group P63/mmc) that is no longer compatible with the often described hexagonal arrangement of tubular micelles but rather with an hexagonal arrangement of spherical micelles. The extent of the hexagonal ordering and the texture can be optimized in films by varying the composition of the solution.

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X-ray and Neutron Study on the Structure of Hydrous SiO2 Glass up to 10 GPa

Minerals ◽

10.3390/min10010084 ◽

2020 ◽

Vol 10 (1) ◽

pp. 84 ◽

Cited By ~ 2

Author(s):

Satoru Urakawa ◽

Toru Inoue ◽

Takanori Hattori ◽

Asami Sano-Furukawa ◽

Shinji Kohara ◽

...

Keyword(s):

Oxide Glasses ◽

Void Space ◽

X Ray Diffraction ◽

Amorphous Sio2 ◽

Sio2 Glass ◽

X Ray ◽

X Ray Scattering ◽

Medium Range ◽

Two Phases ◽

A Minor

The structure of hydrous amorphous SiO2 is fundamental in order to investigate the effects of water on the physicochemical properties of oxide glasses and magma. The hydrous SiO2 glass with 13 wt.% D2O was synthesized under high-pressure and high-temperature conditions and its structure was investigated by small angle X-ray scattering, X-ray diffraction, and neutron diffraction experiments at pressures of up to 10 GPa and room temperature. This hydrous glass is separated into two phases: a major phase rich in SiO2 and a minor phase rich in D2O molecules distributed as small domains with dimensions of less than 100 Å. Medium-range order of the hydrous glass shrinks compared to the anhydrous SiO2 glass by disruption of SiO4 linkage due to the formation of Si–OD deuterioxyl, while the response of its structure to pressure is almost the same as that of the anhydrous SiO2 glass. Most of D2O molecules are in the small domains and hardly penetrate into the void space in the ring consisting of SiO4 tetrahedra.

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Enhancement of Chloroprene/Natural/Butadiene Rubber Nanocomposite Properties Using Organoclays and Their Combination with Carbon Black as Fillers

Polymers ◽

10.3390/polym13071085 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1085

Author(s):

Patricia Castaño-Rivera ◽

Isabel Calle-Holguín ◽

Johanna Castaño ◽

Gustavo Cabrera-Barjas ◽

Karen Galvez-Garrido ◽

...

Keyword(s):

Mechanical Properties ◽

Carbon Black ◽

High Performance ◽

Rubber Matrix ◽

Butadiene Rubber ◽

X Ray Diffraction ◽

X Ray ◽

Rubber Blends ◽

Ft Ir ◽

Chloroprene Rubber

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.

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The Potential for Natural Stones from Northeastern Brazil to Be Used in Civil Construction

Minerals ◽

10.3390/min11050440 ◽

2021 ◽

Vol 11 (5) ◽

pp. 440

Author(s):

Fabiana Pereira da Costa ◽

Jucielle Veras Fernandes ◽

Luiz Ronaldo Lisboa de Melo ◽

Alisson Mendes Rodrigues ◽

Romualdo Rodrigues Menezes ◽

...

Keyword(s):

Mechanical Properties ◽

Thermal Analysis ◽

Differential Thermal Analysis ◽

Chemical Resistance ◽

Mechanical Analysis ◽

Northeastern Brazil ◽

X Ray Diffraction ◽

X Ray ◽

Chemical Agents ◽

Natural Stones

Natural stones (limestones, granites, and marble) from mines located in northeastern Brazil were investigated to discover their potential for use in civil construction. The natural stones were characterized by chemical analysis, X-ray diffraction, differential thermal analysis, and optical microscopy. The physical-mechanical properties (apparent density, porosity, water absorption, compressive and flexural strength, impact, and abrasion) and chemical resistance properties were also evaluated. The results of the physical-mechanical analysis indicated that the natural stones investigated have the potential to be used in different environments (interior, exterior), taking into account factors such as people’s circulation and exposure to chemical agents.

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