Mechanical and microstructural properties of polystyrene based composites: positron lifetime spectroscopic and DSC studies

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Abdullah Mohammed Ali Mohammed Altaweel ◽  
Jaya Madhu Raj ◽  
Malalvalli Nagarajaiah Chandrashekara ◽  
Puttegowda Ramya ◽  
Parthasarathy Sampathkumaran ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Free Volume ◽  
Positron Lifetime ◽  
Tensile Modulus ◽  
Silica Content ◽  
Scanning Calorimetry ◽  
Dsc Studies ◽  
Microstructural Property ◽  
Calcium Aluminosilicate

Abstract Polystyrene (PS) based composites respectively with cenosphere (CS) and calcium aluminosilicate (CAS) as fillers were studied using the positron lifetime technique to reveal the correlation between free volume, a microstructural property, and mechanical properties of the composites (tensile strength and tensile modulus). The thermal stability of the composites was determined using differential scanning calorimetry. The results showed that addition of CAS filler lead to a significant improvement in the mechanical properties of the composite, whereas addition of CS resulted in improvement in tensile modulus only. Both PS/CAS and PS/CS composites showed enhancement in thermal stability compared with that of the pure PS matrix. The positron results showed that the average free volume size for the PS/CAS composite (at 40 phr CAS) was reduced significantly compared with that of the pure PS. These results are understood in terms of the influence of silica content, filler-matrix interaction, and particle size.

Physico Chemical Characterization of Nanofibrous Poly(Ε-Caprolactone) Electrospun Templates for Cell Adhesion

MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2689-2694
Author(s):  
Karla A. Gaspar-Ovalle ◽  
Juan V. Cauich-Rodriguez ◽  
Armando Encinas
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Cell Adhesion ◽  
Tensile Modulus ◽  
Chemical Characterization ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Physico Chemical ◽  
Static Water

ABSTRACTNanofibrous mats of poly ε-caprolactone (PCL) were fabricated by electrospinning. The nanofiber structures were investigated and characterized by scanning electron microscope, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, static water-contact-angle analysis and mechanical properties. The results showed that the nanofibrous PCL is an ideal biopolymer for cell adhesion, owing to its biocompatibility, biodegradability, structural stability and mechanical properties. Differential scanning calorimetry results showed that the fibrous structure of PCL does not alter its crystallinity. Studies of the mechanical properties, wettability and degradability showed that the structure of the electrospun PCL improved the tensile modulus, tensile strength, wettability and biodegradability of the nanotemplates. To evaluate the nanofibrous structure of PCL on cell adhesion, osteoblasts cells were seeded on these templates. The results showed that both adhesion and proliferation of the cells is viable on these electrospun PCL membranes. Thus electrospinning is a relatively inexpensive and scalable manufacturing technique for submicron to nanometer diameter fibers, which can be of interest in the commodity industry.

scholarly journals The effect of isothermal crystallization on mechanical properties of poly(ethylene 2,5-furandicarboxylate)

e-Polymers ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 1-11
Author(s):  
Wei Zhang ◽  
Qingyin Wang ◽  
Gongying Wang ◽  
Shaoying Liu
Keyword(s):  
Mechanical Properties ◽  
Intrinsic Viscosity ◽  
Crystallization Temperature ◽  
Isothermal Crystallization ◽  
Tensile Modulus ◽  
Optical Microscope ◽  
Crystallization Time ◽  
Scanning Calorimetry ◽  
Crystallization Properties ◽  
Poly Ethylene

Abstract The effects of isothermal crystallization temperature/time on mechanical properties of bio-based polyester poly(ethylene 2,5-furandicarboxylate) (PEF) were investigated. The intrinsic viscosity, crystallization properties, thermal properties, and microstructure of PEF were characterized using ubbelohde viscometer, X-ray diffraction, polarizing optical microscope, differential scanning calorimetry, and scanning electron microscopy. The PEF sample isothermal crystallized at various temperatures for various times was denoted as PEF-T-t. The results showed that the isothermal crystallization temperature affected the mechanical properties of PEF-T-30 by simultaneously affecting its crystallization properties and intrinsic viscosity. The isothermal crystallization time only affected the crystallization properties of PEF-110-t. The crystallinity of PEF-110-40 was 17.1%. With small crystal size, poor regularity, and α′-crystal, PEF-110-40 can absorb the energy generated in the tensile process to the maximum extent. Therefore, the best mechanical properties can be obtained for PEF-110-40 with the tensile strength of 43.55 MPa, the tensile modulus of 1,296 MPa, and the elongation at a break of 13.36%.

Thermal stability and dynamic mechanical behavior of functional multiphase boride ceramics/epoxy composites

2019 ◽  
Vol 39 (6) ◽  
pp. 508-514
Author(s):  
Yannan He ◽  
Zhiqiang Yu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Epoxy Composites ◽  
Scanning Calorimetry ◽  
Element Analysis ◽  
Reaction Heat ◽  
Dynamic Mechanical

Abstract The thermal and dynamic mechanical properties of epoxy composites filled with zirconium diboride/nano-alumina (ZrB2/Al2O3) multiphase particles were investigated by means of differential scanning calorimetry, dynamic thermo-mechanical analysis, and numerical simulation. ZrB2/Al2O3 particles were surface organic functional modified by γ-glycidoxypropyltrimethoxysilane for the improvement of their dispersity in epoxy matrix. The results indicated that the curing exotherm of epoxy resin decreased significantly due to the addition of ZrB2/Al2O3 multiphase particles. In comparison to the composites filled with unmodified particles, the modified multiphase particles made the corresponding filling composites exhibit lower curing reaction heat, lower loss modulus, and higher storage modulus. Generally speaking, the composites filled with 5 wt% modified multiphase particles presented the best thermal stability and thermo-mechanical properties due to the better filler-matrix interfacial compatibility and the uniform dispersity of modified particles. Finite element analysis also suggested that the introduction of modified ZrB2/Al2O3 multiphase particles increased the stiffness of the corresponding composites.

DEA and DSC study of cubic silsesquioxane epoxy resin nanocomposites

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Newton Luiz Dias Filho ◽  
Hermes Adolfo de Aquino
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Fracture Toughness ◽  
Differential Scanning Calorimetry ◽  
Epoxy Resin ◽  
Loss Factor ◽  
Tensile Modulus ◽  
Dielectric Analysis ◽  
Epoxy Nanocomposites ◽  
Scanning Calorimetry

AbstractNon-isothermal dielectric analysis (DEA) and differential scanning calorimetry (DSC) techniques were used to study the epoxy nanocomposites prepared by reacting 1,3,5,7,9,11,13,15-octa[dimethylsiloxypropylglycidylether] pentaciclo [9.5.1.13,9.15,15 .17,13] octasilsesquioxane (ODPG) with methylenedianiline (MDA). Loss factor (ε”) and activation energy were calculated by DEA. The relationships between the loss factor, the activation energy, the structure of the network, and the mechanical properties were investigated. Activation energies determined by DEA and DSC, heat of polymerization, fracture toughness and tensile modulus show the same profile for mechanical properties with respect to ODPG content.

Thermal and Thermomechanical Properties of Poly(butylene succinate) Nanocomposites

2008 ◽  
Vol 8 (4) ◽  
pp. 1679-1689 ◽  
Author(s):  
Mamookho E. Makhatha ◽  
Suprakas Sinha Ray ◽  
Joseph Hato ◽  
Adriaan S. Luyt
Keyword(s):  
Thermal Stability ◽  
Tensile Modulus ◽  
Melting Behavior ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Butylene Succinate ◽  
Modulated Differential Scanning Calorimetry ◽  
Thermal Stability Of

This article describes the thermal and thermomechanical properties of poly(butylene succinate) (PBS) and its nanocomposites. PBS nanocomposites with three different weight ratios of organically modified synthetic fluorine mica (OMSFM) have been prepared by melt-mixing in a batch mixer at 140 °C. The structure and morphology of the nanocomposites were characterized by X-ray diffraction (XRD) analyses and transmission electron microscopy (TEM) observations that reveal the homogeneous dispersion of the intercalated silicate layers into the PBS matrix. The thermal properties of pure PBS and the nanocomposite samples were studied by both conventional and temperature modulated differential scanning calorimetry (DSC) analyses, which show multiple melting behavior of the PBS matrix. The investigation of the thermomechanical properties was performed by dynamic mechanical analysis. Results reveal significant improvement in the storage modulus of neat PBS upon addition of OMSFM. The tensile modulus of neat PBS is also increased substantially with the addition of OMSFM, however, the strength at yield and elongation at break of neat PBS systematically decreases with the loading of OMSFM. The thermal stability of the nanocomposites compared to that of the pure polymer sample was examined under both pyrolytic and thermooxidative environments. It is shown that the thermal stability of PBS is increased moderately in the presence of 3 wt% of OMSFM, but there is no significant effect on further silicate loading in the oxidative environment. In the nitrogen environment, however, the thermal stability systematically decreases with increasing clay loading.

Development of New TiO2 Nanoparticles Modified Photosensitive Resin for Rapid Prototyping

2020 ◽  
Vol 12 (2) ◽  
pp. 244-248
Author(s):  
Yiwen Xu ◽  
Shengcai Qi ◽  
Yuanzhi Xu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Rapid Prototyping ◽  
Tensile Modulus ◽  
Heat Stability ◽  
Scanning Calorimetry ◽  
Photosensitive Resin ◽  
Cost Efficient ◽  
Thermal Stability Of

The objective of this study is to enhance the thermal and mechanical properties of the photosensitive resin for RP (Rapid Prototyping) modifying with TiO2 nanoparticles NPs. The coupling agent KH570 was chosen for treating the surface of TiO2 NPs. The influence of the TiO2 content on the viscosity and the curing depth of photosensitive resin were analyzed in this study. We also tested the mechanical properties such as tensile modulus, tensile strength, hardness and flexural strength. Using differential scanning calorimetry, we tested the thermal stability of the modified photosensitive resin. Modified photosensitive resin's comprehensive performance was really good when the content of TiO2 was at 0.25%, the increase in tensile strength from 24.3 to 46.9 MPa was noticed to be 89%, the increase in tensile modulus from 1990 to 2251 MPa was noticed to be 18%, the increase in hardness and flexural strength was noticed to be 5 and 6%, respectively. Moreover, the heat stability and plasticity of the modified photosensitive resin are also enhanced. This paper gives a cost-efficient method of improving the functioning of photosensitive resin for RP.

The properties of sericin/poly(vinyl alcohol) films modified by boric acid

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Qun Wang ◽  
Lu Qi
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Boric Acid ◽  
Vinyl Alcohol ◽  
Water Resistance ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
Blend Ratio ◽  
Percutaneous Drug Delivery ◽  
Thermal Stability Of

AbstractA group of films mainly composed of sericin and poly(vinyl alcohol) (PVA), using boric acid (BA) as a modifier, were prepared by a technique of solution casting. In this work, the effect of BA and sericin on the mechanical properties and water resistance of the films was analyzed, the interior morphology of the films were described by a scanning electron microscopy (SEM), the thermal stability of the films was characterized by differential scanning calorimetry (DSC), and the reaction mechanism was proposed according to the previous literature and the test of Fourier transform infrared spectrum (FTIR). Results indicated that, the properties of the membrane were the functions of the blend ratio of sercin to PVA and the content of BA. The use of BA increased the tensile strength, improved the water resistance and the thermal stability, and varied the interior morphology of the films. The content of sericin greatly influenced the combination of properties of the films, especially the mechanical properties, interior morphology, thermal stability, and water resistance reducing with the increasing of sericin content. The films have potential to be used in materials, such as skin-care coatings for beauty, percutaneous drug delivery systems for exterior intact skin, due to the characteristics of the components and the good mechanical properties of the films.

TEM and DSC Studies on the Synthetic Diamond Grown from Fe-Ni-C-B System under HPHT

2011 ◽  
Vol 320 ◽  
pp. 3-7
Author(s):  
Jian Hong Gong ◽  
Shu Xia Lin ◽  
Jun Gao
Keyword(s):  
Thermal Stability ◽  
Boron Content ◽  
Synthetic Diamond ◽  
Scanning Calorimetry ◽  
Dsc Studies ◽  
Diamond Crystals ◽  
Transmission Electron ◽  
High Pressure High Temperature ◽  
Alloy Catalysts ◽  
Thermal Stability Of

Transmission Electron Microscope (TEM) and Different Scanning Calorimetry (DSC) Methods Were Used to Investigate the Diamonds Grown with Different Boron Content Alloy Catalysts under High-Pressure High-Temperature (HPHT). Experimental Results Demonstrated the Microstructure and Composition of Boride Compounds in Synthetic Diamond, such as (FeNi)23(CB)6 ,(Fe, Ni)3(C,B), (Fe,Ni)B and B4C, Whose Formation Process Was Analyzed. the Thermal Stability of Diamond Depends on Boron Concentration in Catalyst According to DSC Studies. we Analyzed the Reason of Diamond Oxidation.The Work Offers Valuable Information for Improving the Thermal Stability of Synthetic Diamond Crystals by Adjusting Boron Content in the Fe-Ni Based Catalyst.

scholarly journals Study of Mechanical Properties of PHBHV/Miscanthus Green Composites Using Combined Experimental and Micromechanical Approaches

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2650
Author(s):  
Thibault Lemaire ◽  
Erica Gea Rodi ◽  
Valérie Langlois ◽  
Estelle Renard ◽  
Vittorio Sansalone
Keyword(s):  
Mechanical Properties ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
Specific Class ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Green Wood ◽  
Miscanthus Giganteus ◽  
The One

In recent years the interest in the realization of green wood plastic composites (GWPC) materials has increased due to the necessity of reducing the proliferation of synthetic plastics. In this work, we study a specific class of GWPCs from its synthesis to the characterization of its mechanical properties. These properties are related to the underlying microstructure using both experimental and modeling approaches. Different contents of Miscanthus giganteus fibers, at 5, 10, 20, 30 weight percent’s, were thus combined to a microbial matrix, namely poly (3-hydroxybutyrate)-co-poly(3-hydroxyvalerate) (PHBHV). The samples were manufactured by extrusion and injection molding processing. The obtained samples were then characterized by cyclic-tensile tests, pycnometer testing, differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and microscopy. The possible effect of the fabrication process on the fibers size is also checked. In parallel, the measured properties of the biocomposite were also estimated using a Mori–Tanaka approach to derive the effective behavior of the composite. As expected, the addition of reinforcement to the polymer matrix results in composites with higher Young moduli on the one hand, and lower failure strains and tensile strengths on the other hand (tensile modulus was increased by 100% and tensile strength decreased by 23% when reinforced with 30 wt % of Miscanthus fibers).

scholarly journals Dispersibility of Kaolinite-Rich Coal Gangue in Rubber Matrix and the Mechanical Properties and Thermal Stability of the Composites

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1388
Author(s):  
Kenan Zhang ◽  
Hao Zhang ◽  
Linsong Liu ◽  
Yongjie Yang ◽  
Lihui Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Coal Gangue ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Scanning Calorimetry ◽  
Laser Scattering ◽  
X Ray ◽  
Thermal Stability Of

The aim of this work was to investigate the dispersibility of kaolinite-rich coal gangue in rubber matrix, the mechanical properties and thermal stability of coal gangue/styrene butadiene rubber (SBR) composites, and to compare these properties to those of the same coal gangue but had undergone thermal activation and modification. Several experimental techniques, such as X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric-differential scanning calorimetry (TG-DSC), laser-scattering particle analyzer were adopted to characterize the coal gangue particles and then the obtained composites. The results demonstrated the raw coal gangue (RCG) was mainly composed of kaolinite. Calcination led to amorphization of thermal activated coal gangue (ACG), increased hydrophilicity and void volume, and decreased pH. The grain size of ACG became coarser than RCG, but ACG turned loose confirmed by higher degree of refinement after grinding. Modification enhanced the hydrophobicity of the coal gangue and improved its dispersibility than fillers without modification. Calcined samples had better dispersibility than uncalcined fillers. Additionally, the coal gangue treated by calcinating, grinding and modifying (MGA) had the best dispersion in rubber matrix. Either calcination or modification could improve the mechanical properties and thermal stability of coal gangue filled rubber, while the performance of MGA reinforced SBR (MGA-SBR) was the best. The enhanced performance of the MGA-SBR was owed to better dispersion of particles as well as stronger interactions between particles and rubber macromolecules.

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