Investigation of Free Volume Size and Mechanical Properties for PolymethylMethacrylate/Organic Rectorite Composites by PALS

2011 ◽  
Vol 233-235 ◽  
pp. 1868-1871
Author(s):  
Wei Zhou ◽  
Yan Sheng Gong
Keyword(s):  
Mechanical Properties ◽  
Free Volume ◽  
Atomic Scale ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Scale Free ◽  
Bending Modulus ◽  
Weight Content ◽  
The Relationship ◽  
Volume Size

PolymethylMethacrylate (PMMA) composites with different weight content of organic rectorite (OREC) are prepared via melt blending. The results of X-ray diffraction (XRD) show that the layer distance of OREC is much larger than that of the pristine rectorite. SEM images reveal that the OREC filler has been well dispersed in matrix. With the addition of OREC, Bending modulus increased obviously. Ortho-positronium (o-Ps) lifetimes show that the free volume sizes of PMMA/OREC composites are larger than those of the PMMA matrix. The relationship between the atomic-scale free volume size and mechanical properties is preliminarily discussed in this work.

scholarly journals Influence of Temperature on Mechanical Properties of P(BAMO-r-THF) Elastomer

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2507
Author(s):  
Jinxian Zhai ◽  
Hanpeng Zhao ◽  
Xiaoyan Guo ◽  
Xiaodong Li ◽  
Tinglu Song
Keyword(s):  
Mechanical Properties ◽  
X Ray Diffraction ◽  
Polymeric Chains ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Strain Induced Crystallization ◽  
Thermal Histories ◽  
Static Conditions ◽  
The Relationship ◽  
Induced Crystallization

The relationship between temperature and the mechanical properties of an end cross-linked equal molar random copolyether elastomer of 3,3-bis(azidomethyl)oxetane and tetrahydrofuran (P(BAMO-r-THF)) was investigated. During this investigation, the performances of two P(BAMO-r-THF) elastomers with different thermal histories were compared at different temperatures. The elastomer as prepared at 20 °C (denoted as S0) exhibited semi-crystallization morphology. Wide angle X-ray diffraction analysis indicated that the crystal grains within elastomer S0 result from the crystallization of BAMO micro-blocks embedded in P(BAMO-r-THF) polymeric chains, and the crystallinity is temperature irreversible under static conditions. After undergoing a heating-cooling cycle, this elastomer became an amorphous elastomer (denoted as S1). Regarding mechanical properties, at 20 °C, break strains and stresses of 315 ± 22% and 0.46 ± 0.01 MPa were obtained for elastomer S0; corresponding values of 294 ± 6% and 0.32 ± 0.02 MPa were obtained for elastomer S1. At −40 °C, these strains and stresses simultaneously increased to 1085 ± 21% and 8.90 ± 0.72 MPa (S0) and 1181 ± 25% and 10.23 ± 0.44 MPa (S1), respectively, owing to the strain-induced crystallization of BAMO micro-blocks within the P(BAMO-r-THF) polymeric chains.

Preparation and Mechanical Properties of BiFeO3 Ceramics

2016 ◽  
Vol 697 ◽  
pp. 293-296
Author(s):  
Xiao Yang Zhang ◽  
Xi Wei Qi ◽  
Zhi Yuan Yang ◽  
Li Bao ◽  
Min Zhang
Keyword(s):  
Mechanical Properties ◽  
Hydrothermal Method ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Cold Isostatic Pressing ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Three Point Bending ◽  
Multiferroic Bifeo ◽  
Sol Gel Process

Hydrothermal method and sol-gel process were used to synthesize multiferroic BiFeO3 ceramics. X-ray diffraction, scanning electron microscopy, vickers diamond indenter and three-point bending method were used to investigate the effects of methods on the phase structure, microstructures and mechanical properties. Cold isostatic pressing on the ceramics with two different loads (10 MPa, 200 MPa) was used to illustrate the influence of pressure in mechanical properties. The results show that all samples are crystallized in the perovskite phase. A few small traces of impurity are observed at a 2θ of ~28 o, which are found to be those of Bi2Fe4O9. The SEM images depict that samples prepared by sol-gel process are more uniform and the grain size is slightly larger than that of hydrothermal processed samples. The investigations on the hardness and flexural strength demonstrate the ceramics prepared by hydrothermal method have better mechanical properties than that of sol-gel process, and the mechanical properties can be obviously enhanced by increasing pressure.

scholarly journals Isotropic microscale mechanical properties of coral skeletons

2015 ◽  
Vol 12 (106) ◽  
pp. 20150168 ◽  
Author(s):  
Luca Pasquini ◽  
Alan Molinari ◽  
Paola Fantazzini ◽  
Yannicke Dauphen ◽  
Jean-Pierre Cuif ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Nacreous Layer ◽  
X Ray Diffraction ◽  
Stylophora Pistillata ◽  
Force Microscopy ◽  
Coral Skeletons ◽  
Atomic Force ◽  
Diffraction Patterns ◽  
The Relationship ◽  
Atrina Rigida

Scleractinian corals are a major source of biogenic calcium carbonate, yet the relationship between their skeletal microstructure and mechanical properties has been scarcely studied. In this work, the skeletons of two coral species: solitary Balanophyllia europaea and colonial Stylophora pistillata , were investigated by nanoindentation. The hardness H IT and Young's modulus E IT were determined from the analysis of several load–depth data on two perpendicular sections of the skeletons: longitudinal (parallel to the main growth axis) and transverse. Within the experimental and statistical uncertainty, the average values of the mechanical parameters are independent on the section's orientation. The hydration state of the skeletons did not affect the mechanical properties. The measured values, E IT in the 76–77 GPa range, and H IT in the 4.9–5.1 GPa range, are close to the ones expected for polycrystalline pure aragonite. Notably, a small difference in H IT is observed between the species. Different from corals, single-crystal aragonite and the nacreous layer of the seashell Atrina rigida exhibit clearly orientation-dependent mechanical properties. The homogeneous and isotropic mechanical behaviour of the coral skeletons at the microscale is correlated with the microstructure, observed by electron microscopy and atomic force microscopy, and with the X-ray diffraction patterns of the longitudinal and transverse sections.

Studies on mechanical properties, dielectric behavior and DC conductivity of neodymium oxide/poly (butyl methacrylate) nanocomposites

2020 ◽  
pp. 096739112096065
Author(s):  
K Suhailath ◽  
Meenu Thomas ◽  
MT Ramesan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Neodymium Oxide ◽  
Dielectric Behavior ◽  
Dc Conductivity ◽  
Butyl Methacrylate ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Uniform Dispersion

The current article aims to develop poly (butyl methacrylate) (PBMA) nanocomposites with enhanced electrical and mechanical properties by incorporating neodymium oxide (Nd2O3) nanoparticles between the PBMA chains. The morphological, thermal and structural profiles of the PBMA nanocomposites reinforced with different loading of Nd2O3 nanoparticles were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The SEM images revealed that the morphology of the PBMA was significantly influenced by the insertion of Nd2O3. The uniform dispersion of Nd2O3 in the polymer composite was visible at 5 wt% loading of nano-filler. The main crystalline peaks of Nd2O3 nanoparticles in the amorphous PBMA structure were revealed by the X-ray diffraction analysis. The thermal stability of PBMA was greatly enhanced by the dispersion of Nd2O3 in the PBMA matrix. The tensile strength and elongation at break of the composites were measured and both results showed the enhanced mechanical properties of PBMA due to the reinforcement of Nd2O3 nanoparticles. The various parameters affecting the increased tensile strength of composite by the incorporation of nanoparticles were studied by different theoretical modeling. The electrical properties such as dielectric constant and the dielectric loss tangent (tan δ) of PBMA nanocomposites were enhanced with the addition of nanoparticles. Also, the DC conductivity of polymer composites was estimated and the applicability of different theoretical models for predicting the conductivity properties of PBMA/Nd2O3 nanocomposites were examined.

scholarly journals The Effect of Incorporating Silica Stone Waste on the Mechanical Properties of Sustainable Concretes

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3832 ◽  
Author(s):  
Saeid Abbasi ◽  
Mohammad Hemen Jannaty ◽  
Rabar H. Faraj ◽  
Shahriar Shahbazpanahi ◽  
Amir Mosavi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Sustainable Construction ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Sem Images ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
The Matrix ◽  
First Time

Incorporating various industrial waste materials into concrete has recently gained attention for sustainable construction. This paper, for the first time, studies the effects of silica stone waste (SSW) powder on concrete. The cement of concrete was replaced with 5, 10, 15, and 20% of the SSW powder. The mechanical properties of concrete, such as compressive and tensile strength, were studied. Furthermore, the microstructure of concrete was studied by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy analysis (EDX), Fourier transformed infrared spectroscopy (FTIR), and X-Ray diffraction (XRD) tests. Compressive and tensile strength of samples with 5% SSW powder was improved up to 18.8% and 10.46%, respectively. As can be observed in the SEM images, a reduced number of pores and higher density in the matrix can explain the better compressive strength of samples with 5% SSW powder.

Effect of the Degree of Branching on Atomic-Scale Free Volume in Hyperbranched Poly[3-ethyl-3-(hydroxymethyl)oxetane]. A Positron Study

2005 ◽  
Vol 38 (23) ◽  
pp. 9644-9649 ◽  
Author(s):  
Wei Gong ◽  
Yiyong Mai ◽  
Yongfeng Zhou ◽  
Ning Qi ◽  
Bo Wang ◽  
...  
Keyword(s):  
Free Volume ◽  
Atomic Scale ◽  
Degree Of Branching ◽  
Scale Free ◽  
Hyperbranched Poly

Atomic Scale Investigation of Cr Precipitation in Cu and Related Mechanical Properties.

2011 ◽  
Vol 172-174 ◽  
pp. 291-296
Author(s):  
Abdelahad Chbihi ◽  
Xavier Sauvage ◽  
Didier Blavette
Keyword(s):  
Mechanical Properties ◽  
Phase Diagram ◽  
Atom Probe Tomography ◽  
Quantitative Data ◽  
Volume Fraction ◽  
Early Stage ◽  
Atom Probe ◽  
Atomic Scale ◽  
Precipitation Sequence ◽  
The Relationship

The early stages of precipitation of Cr rich precipitates were investigated by Atom Probe Tomography (APT) in a Cu-1Cr-0.1Zr (wt.%). This way, quantitative data were obtained about their size, 3D shape, density, composition and volume fraction. Surprisingly, in the early stage of precipitation, nanoscaled precipitates exhibit various shapes (spherical, plates and ellipsoid) and contain a large amount of Cu (up to 50%), in contradiction with the equilibrium Cu-Cr phase diagram. APT data also show that some impurities (Fe) segregate along Cu/Cr interfaces. A precipitation sequence is proposed and the relationship between mechanical properties and microstructure is discussed.

Synthesis of Poly(Methyl Methacrylate) Reinforced by Graphene Nanoplates

2021 ◽  
Vol 897 ◽  
pp. 63-70
Author(s):  
Elif Kocacinar ◽  
Nilgun Baydogan
Keyword(s):  
Mechanical Properties ◽  
Methyl Methacrylate ◽  
In Situ Polymerization ◽  
Technical Problem ◽  
Test Method ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Poly Methyl Methacrylate ◽  
Superior Mechanical Properties ◽  
Dispersion Problem

Graphene nanoplatelets (GNPs) was used as a nanofiller in Poly(methyl methacrylate) (PMMA) synthesized by the Atom Transfer Radical Polymerization (ATRP) method. The first step in the synthesis of the PMMA/GNPs was the dispersion of GNPs in the PMMA liquid monomers by combining the solutions so that GNPs had superior mechanical properties, thermal stability, and electrical conductivity also lower density of mass. Then the crosslinked PMMA/GNPs nanocomposite samples were synthesized by using the in-situ polymerization method. However, there was a challenging technical problem in the application of GNPs (at a large amount) in the polymer. For the purpose of benefiting from the advantageous properties of GNPs (especially in bulk quantities) at PMMA, the major problem at the synthesis of PMMA/GNPs nanocomposite was the GNPs dispersion in the polymer matrix. This research has focused on solving that dispersion problem with the aim of enhancing the mechanical properties of the nanocomposite by utilizing the ATRP method as the effective production technic. The structural characterization of PMMA/GNPs nanocomposite was performed for the examination of the integration of GNPs in PMMA. The surface morphology of the nanocomposite was analyzed using SEM images. X-Ray Diffraction (XRD) as a non-destructive test method was used to examine the changes in the crystalline properties of the nanocomposite structure with the rise of the GNPs amount in PMMA. The bonding interactions with each other were investigated by using Raman analysis.

scholarly journals Helium Effects on the Mechanical Properties of Nanocrystalline Fe: Based on Molecular Dynamics

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 532
Author(s):  
Chunping Xu ◽  
Dongyan Yang
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Lattice Distortion ◽  
Tensile Deformation ◽  
Peak Stress ◽  
X Ray Diffraction ◽  
Peak Separation ◽  
Tensile Process ◽  
Xrd Patterns ◽  
The Relationship

A molecular dynamics (MD) simulation study was performed to investigate the effects of helium (He) on the mechanical properties of nanocrystalline body-centered cubic iron (BCC Fe). Simulated X-ray diffraction (XRD) was used to explore the relationship between the generation of cracks and the change of the crystal structure in nanocrystalline BCC Fe during tensile deformation. It is observed that the peak stress and the elastic modulus decrease with increasing concentration of He atoms, which are introduced into the grain boundary (GB) region of nanocrystalline Fe. The generation and connection of intergranular cracks are enhanced by He atoms. Significant peak separation, which is associated with the generation of cracks, is found in the simulated XRD patterns of nanocrystalline Fe during the tensile process. The lower diffraction angle of the {211}′ peak suggests a more serious lattice distortion during loading. For all nanocrystalline Fe deformed to 6% strain, the degree and fraction of the lattice distortion increases with the increasing loading stress.

scholarly journals Design and Performance Research on Dual Layer Cement Based Absorber Reinforced with Graphene Nanosheets and Manganese-zinc Ferrite

2021 ◽  
Author(s):  
Yafei SUN ◽  
Tianshu ZHOU ◽  
Yueyue PENG ◽  
Hongwei LIU
Keyword(s):  
Mechanical Properties ◽  
Electrical Resistivity ◽  
Zinc Ferrite ◽  
Graphene Nanosheets ◽  
Effective Bandwidth ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Manganese Zinc ◽  
Manganese Zinc Ferrite ◽  
And Performance

Dual layer cement-based absorber is synthesized by mixing with graphene nanosheets and manganese-zinc ferrite, to study the effect of absorbing filler content on the mechanical properties, microstructure, electrical resistivity and reflectivity of the paste. The microstructure of the absorber is seen by Scanning Electron Microscope (SEM) images, Fourier Transform Infrared (FTIR) spectroscopy, X-Ray Diffraction (XRD) curves of the absorber. The results show that graphene nanosheets significantly reduce the electrical resistivity of paste, increasing its mechanical properties by improving its pore structure. SEM images indicate that graphene nanosheets promote the increase and coarsening of cement hydration products and produce a large number of dense bulk crystals. Furthermore, reflectivity measurements show that the minimum reflectivity of – 14.1 dB is obtained in the range of 2 ~ 18 GHz and the effective bandwidth of 16 GHz is obtained when reflectivity is less than – 7 dB. This study provides a new method for the preparation of dual layer cement-based absorber.

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