scholarly journals Effect of Radiation-Induced Cross-Linking on Thermal Aging Properties of Ethylene-Tetrafluoroethylene for Aircraft Cable Materials

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 257
Author(s):  
Xiaodong Zhang ◽  
Fei Chen ◽  
Zhimin Su ◽  
Taiping Xie
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Thermo Gravimetric Analysis ◽  
Thermal Characteristics ◽  
Volume Resistivity ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Aging Properties ◽  
Radiation Induced ◽  
Ethylene Tetrafluoroethylene

The effects of electron beam irradiation on ethylene-tetrafluoroethylene copolymer (ETFE) were studied. Samples were irradiated in air at room temperature by a universal electron beam accelerator for various doses. The effect of irradiation on samples and the cross-linked ETFE after aging were investigated with respect to thermal characteristics, crystallinity, mechanical properties, and volume resistivity using thermo-gravimetric analysis (TGA), differential scanning calorimeter (DSC), universal mechanical tester, and high resistance meter. TGA showed that thermal stability of irradiated ETFE is considerably lower than that of unirradiated ETFE. DSC indicates that crystallinity is altered greatly by cross-link. The analysis of mechanical properties, fracture surface morphology, visco-elastic properties and volume resistivity certify radiation-induced cross-linking is vital to aging properties.

Processing and MWNT Composition Effects on the Thermal, Electrical and Mechanical Properties of PLA-MWNT Composites

2009 ◽  
Author(s):  
Reza R. Rizvi ◽  
Jae K. Kim ◽  
Hani E. Naguib
Keyword(s):  
Mechanical Properties ◽  
Thermo Gravimetric Analysis ◽  
Composite Films ◽  
Thermal Characteristics ◽  
Casting Process ◽  
Decomposition Temperature ◽  
Multiwall Carbon Nanotube ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Electrical Percolation

This paper investigates the processing and its effects and the effect of multiwall carbon nanotube (MWNT) composition on the thermal, electrical and mechanical properties of polylactide (PLA)-MWNT composites. The composite films were prepared by a solvent casting process using two solvents, chloroform and 1,4-dioxane. The dispersion of the MWNTs in PLA was examined using a scanning electron microscope and was found to be more improved when 1,4-dioxane was used as the solvent as compared to chloroform. The thermal characteristics of the composites were examined on Differential Scanning Calorimetry and Thermo-gravimetric Analysis. Composites prepared using 1,4-dioxane had greater improvements in composite decomposition temperature, glass transition temperature and displayed faster crystallization kinetics. The mechanical properties of the composites were tested in uniaxial tension. Composites prepared using chloroform had a lower modulus than composites prepared using 1,4-dioxane. The electrical AC conductivity of the composites was measured over a broad frequency spectrum. Composites prepared using 1,4-dioxane displayed electrical percolation at 0.5 wt.% MWNT in PLA while percolation was absent in 0.5 wt.% MWNT composites prepared using chloroform.

scholarly journals Biocomposites of Bio-Polyethylene Reinforced with a Hydrothermal-Alkaline Sugarcane Bagasse Pulp and Coupled with a Bio-Based Compatibilizer

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2158
Author(s):  
Nanci Vanesa Ehman ◽  
Diana Ita-Nagy ◽  
Fernando Esteban Felissia ◽  
María Evangelina Vallejos ◽  
Isabel Quispe ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Water Absorption ◽  
Sugarcane Bagasse ◽  
Thermo Gravimetric Analysis ◽  
Decomposition Temperature ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Cradle To Gate ◽  
Bagasse Pulp

Bio-polyethylene (BioPE, derived from sugarcane), sugarcane bagasse pulp, and two compatibilizers (fossil and bio-based), were used to manufacture biocomposite filaments for 3D printing. Biocomposite filaments were manufactured and characterized in detail, including measurement of water absorption, mechanical properties, thermal stability and decomposition temperature (thermo-gravimetric analysis (TGA)). Differential scanning calorimetry (DSC) was performed to measure the glass transition temperature (Tg). Scanning electron microscopy (SEM) was applied to assess the fracture area of the filaments after mechanical testing. Increases of up to 10% in water absorption were measured for the samples with 40 wt% fibers and the fossil compatibilizer. The mechanical properties were improved by increasing the fraction of bagasse fibers from 0% to 20% and 40%. The suitability of the biocomposite filaments was tested for 3D printing, and some shapes were printed as demonstrators. Importantly, in a cradle-to-gate life cycle analysis of the biocomposites, we demonstrated that replacing fossil compatibilizer with a bio-based compatibilizer contributes to a reduction in CO2-eq emissions, and an increase in CO2 capture, achieving a CO2-eq storage of 2.12 kg CO2 eq/kg for the biocomposite containing 40% bagasse fibers and 6% bio-based compatibilizer.

scholarly journals SiO2 particles effect on the mechanical properties of the starch/PVA blends

2018 ◽  
Vol 16 (36) ◽  
pp. 153-171
Author(s):  
Nahida J. H.
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Ultimate Strength ◽  
Thermo Gravimetric Analysis ◽  
Polymer System ◽  
Optical Microscope ◽  
Gravimetric Analysis ◽  
Ratio Increase

The present work studies the mechanical properties of SiO2 μPs, and NPs in St/PVA blends. The samples were prepared by casting method as PVA, St/PVA blends at different concentrations (30, 40, 50, and 60 %). DSC and TGA tests were carried out to the samples evolved. The result showed a single glass transition temperature (Tg) for all St /PVA blends that was attributed to the good miscibility of the blends involved. It was found that (Tg) decrease with starch ratio increase. It was seen that (PVA) of (Tg=105 oC); The glass transition temperature which was decrease with starch ratio that was attributed to glass transition relaxation process due to micro-Brownian motion of the main chain back bond. The endothermic peak at 200 oC was attributed to melting point of (PVA). Thermal properties of PVA; and St /PVA blends at different concentration (30, 40, 50, and 60 %) were evaluated by thermo gravimetric analysis (TGA). The analyses were carried out from 20 to 600 oC at 10 oC)/min heating rate in air oxygen atmosphere. The weight loss stages depended on polymer system. The starch addition causing shifting in the second degradation temperature to the higher temperature; which result in overlapping between the two main degradation steps, these result was attributed to the St/ PVA blend compatibility. The mechanical properties results showed a decrease in ultimate strength with starch ratio increase. The ultimate strength of (PVA) was (47 MPa), whereas the ultimate strength of 60 %St/PVA was (11 MPa) and for 30 %St/PVA was the highest ultimate strength of blends involved (26 MPa). SiO2μPs (753.7 nm), and NPs (263.1 nm) were added at different concentrations (1.5, 2, and 2.5 %). 1.5% SiO2μPs, and NPs of the best ultimate strength (69 MPa), (86 MPa) respectively then it was decreased by SiO2μPs, and NPs increase. Optical microscope of the samples involved was investigated. It was concluded the prepared samples were suggested to be used as packaging materials for agriculture application and its ultimate strength could be controlled by SiO2μPs, and NPs addition.

Preparation of N-Methylpolyborosilazane -Derived Bulk Si-B-N-C Ceramics by Warm-Pressing and Pressureless Pyrolysis

2012 ◽  
Vol 557-559 ◽  
pp. 1148-1151
Author(s):  
Zhen Quan Liu ◽  
Jing Zhang ◽  
Xian Xing Qiu ◽  
Yu Qing Peng ◽  
Ke Qing Han ◽  
...  
Keyword(s):  
High Temperature ◽  
Ceramic Body ◽  
Thermo Gravimetric Analysis ◽  
Amorphous Structure ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Green Body ◽  
Thermo Gravimetric ◽  
Temperature Resistance ◽  
Bulk Ceramic

Additive-free bulk Si-B-N-C ceramics were prepared by pyrolysis of preceramic precursor (PBS-Me), which mainly involves cross linking, warm-pressing and pyrolysis. The density of crack-free bulk ceramic attains 1.94 g/cm3 when Calcined at 1300 °C. The shaped workpieces exhibit amorphous structure even be pyrolysised at 1400°C in N2, and there are some pores existing in the green body derived from warm-pressing and the resulting Si-B-N-C ceramic body, and these pores allow the gaseous byproducts be expeled from bodies. The pyrolyzed samples were studied by high temperature thermo gravimetric analysis, it shows that the Si-B-N-C body had an excellent high temperature resistance.

Effect of Alumina Ceramic Powder Dispersion on Mechanical Properties of PolyPropylene Polymers

2012 ◽  
Vol 727-728 ◽  
pp. 1729-1733 ◽  
Author(s):  
Germannya D.A. Silva ◽  
Kleber G.B. Alves ◽  
Yeda B. Almeida ◽  
Ricardo A. Sanguinetti ◽  
Yogendra Prasad Yadava
Keyword(s):  
Mechanical Properties ◽  
Ceramic Powder ◽  
Thermo Gravimetric Analysis ◽  
Tensile Tests ◽  
Gravimetric Analysis ◽  
Melt Blending ◽  
Thermo Gravimetric ◽  
Sem Images ◽  
Hard Particles ◽  
Pp Composites

The objectives of this paper are study effect of dispersion of hard alumina (Al2O3) microparticles-filled polypropylene (PP) composites. Al2O3/PP composites containing 1.0 – 5.0 wt% of the Al2O3 were prepared through melt blending and specimens were produced through injection moulding technique. This study sets out to evaluate the influence of adding hard particles to the mechanical properties of the composite obtained while keeping the processing characteristics of the material. The material was characterized as thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). The tensile tests performed showed an increase in the mechanical properties of the composite (modulus and elongation (%)) by increasing the Al2O3 content. The SEM images show a change in the fracture behavior between pure PP (brittle fracture) and Al2O3/PP composites containing 3.0 and 5.0 wt % (ductile fracture). The research aims to establish a new parameter for the development of products and advances in the application of this material.

scholarly journals Correlations Between Alkali and Crystallinity in lyocell-Based ACF Probed with X-Ray Diffraction

2020 ◽  
Vol 58 (7) ◽  
pp. 495-500
Author(s):  
Young Min Jin ◽  
Joon Hyuk Lee ◽  
Sang Sun Choi
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Thermal Characteristics ◽  
Degree Of Crystallinity ◽  
Bet Surface Area ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Potential Applications ◽  
Activated Carbon Fibres

This study examined the effect of alkalis on lyocell-based activated carbon fibres (ACFs) with high Brunauer-Emmett-Teller (BET) surface areas, using X-ray diffraction (XRD). Here, alkali treatments were conducted using 10 ~ 25 % NaOH and KOH on lyocell samples for 3 h at ambient room temperature. A secondary treatment with 4 % each of KOH and H3PO4 for an additional 3 h followed. An activated form of the samples was prepared by oxidation (stabilisation), carbonisation, and activation. The final ACF form of the samples showed a porous structure with high BET surface areas (> 1,000 m<sup>2</sup> g<sup>-1</sup>). A 25 % dosage of NaOH produced the highest BET surface area compared to other samples. In terms of crystallinity, a 15 % dosage of KOH was found to be the optimum dosage to secure the highest degree of crystallinity among all samples. Meanwhile, the NaOH was successfully shifted the samples into the most distinct form of cellulose II. 15 % NaOH was found to secure the most stable thermal characteristics, as determined via thermo-gravimetric analysis. The present work demonstrates the various physio-chemistries of ACFs prepared with different proportions and types of alkalis, leading to intriguing potential applications.

scholarly journals Construction of Cellulose/Carboxymethyl Chitosan Hydrogels for Potential Wound Dressing Application

2021 ◽  
Author(s):  
Yi Guo ◽  
Chuanyin Zhao ◽  
Chao Yan ◽  
Li Cui
Keyword(s):  
Wound Dressing ◽  
Thermo Gravimetric Analysis ◽  
Pore Wall ◽  
Carboxymethyl Chitosan ◽  
Cross Linking ◽  
Cellulose Content ◽  
Gravimetric Analysis ◽  
Composite Hydrogels ◽  
Equilibrium Swelling Ratio ◽  
Chitosan Hydrogels

Abstract In this study, novel cellulose/carboxymethyl chitosan (CMCS) composite hydrogels were constructed by blending cellulose and CMCS in LiOH/urea aqueous solutions, and then cross-linking with epichlorohydrin. The structure and morphology of the composite hydrogels were characterized by Fourier transform infrared spectroscopy (FT-IR), wide-angle X-ray diffraction (WXRD), thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results revealed that the chemical cross-linking reaction between cellulose and CMCS occurred in the hydrogel, and CMCS contributed to the enhancement of pore size, whereas cellulose as a strong backbone in the hydrogel to support the pore wall. The mechanical strength of the composite hydrogels increased with the cellulose content, while the equilibrium swelling ratio and antibacterial activity increased with the CMCS content. The composite hydrogels had no cytotoxicity towards L929 cells, suggesting good biocompatibility. All these results indicate that cellulose/CMCS composite hydrogels can be effectively used as a material in wound dressing.

scholarly journals Ultra-nano indentation properties of crosslinked PBT

2018 ◽  
Vol 210 ◽  
pp. 02038
Author(s):  
Martin Ovsik ◽  
Tomas Fiala ◽  
Miroslav Manas ◽  
Adam Dockal
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Crosslinking Agent ◽  
Industrial Applications ◽  
Basic Material ◽  
Polybutylene Terephthalate ◽  
Beam Radiation ◽  
Nano Indentation ◽  
Engineering Plastics ◽  
Radiation Induced

This article deals with the use of Ultra-nano indentation Tester UNHT3 for the measurement of (ultra nano) mechanical properties. The effect of electron beam (EB) radiation on Polybutylene terephthalate (PBT) was investigated. To clarify whether crosslinking could take place without or only with the presence of a crosslinking agent, special attention was paid to the incorporation of this agent into tested polymer. In this study we have investigated the effect of crosslinking agent, and instantaneously electron beam radiation-induced crosslinking in the presence of Triallyl cyanurate on various mechanical properties of PBT. The results show that the influence of radiation has improved the observed properties in the surface layer. The increase in ultra-nano properties was around 26% over the basic material. Engineering plastics like Poly (butylene terephthalate) due to their desirable properties have various industrial applications.

Effect of ZrO2 Nanofiller on the Physical Properties of Epoxy Composites: Mechanical, Thermal and Dielectric

2021 ◽  
Vol 14 (5) ◽  
pp. 425-435
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Thermo Gravimetric Analysis ◽  
Thermal Characteristics ◽  
Zirconium Oxychloride ◽  
Precipitation Method ◽  
Zro2 Nanoparticles ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Zirconia Nanoparticles

Abstract: In this present work, Zirconia nanoparticles were prepared by precipitation method, Zirconium Oxychloride (ZrOCl2.8H2O) and ammonia (NH3) as starting materials. The synthesized Zirconia nanoparticles were characterized by XRD and the grain size in nanoscale was confirmed. The sheets of neat epoxy resin and epoxy with addition of ZrO2 nanoparticles are primed by solution casting method. The structures of epoxy polymer and hardener were found out using FTIR analysis. The thermal properties were analyzed using Thermo Gravimetric Analysis (TGA) and Differential Thermal Analysis (DTA). Thermo gravimetric analysis has been employed to investigate the thermal characteristics and their mode of thermal degradation. Differential thermal analysis has been used to determine the glass transition temperature of epoxy nanocomposites. The mechanical properties like tensile and flexural studies were analyzed and thus influences of nanofiller loading on these parameters were found to be very low. Keywords: Epoxy, ZrO2 nanoparticles, Nanocomposites, Thermal stability, Dielectric properties, Tensile strength, Flexural strength.

SYNTHESIS OF HYBRID SiC/SiO2 NANOPARTICLES AND THEIR POLYMER NANOCOMPOSITES

2013 ◽  
Vol 12 (02) ◽  
pp. 1350008 ◽  
Author(s):  
TARIG A. HASSAN ◽  
VIJAYA K. RANGARI ◽  
FREDRIC BAKER ◽  
SHAIK JEELANI
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
High Intensity ◽  
Thermo Gravimetric Analysis ◽  
Neat Epoxy ◽  
Hybrid Nanoparticles ◽  
Gravimetric Analysis ◽  
Sonochemical Method ◽  
Thermal And Mechanical Properties ◽  
Sic Nanoparticles

In the present investigation, silicon carbide (β-SiC) nanoparticles (~ 30 nm) were coated on silicon dioxide (SiO2) nanoparticles (~ 200 nm) using sonochemical method. The resultant hybrid nanoparticles were then infused into SC-15 epoxy resin to enhance the thermal and mechanical properties of SC-15 epoxy for structural application. To fabricate an epoxy-based nanocomposite containing SiC/SiO2 hybrid nanoparticles, we have opted a two-step process. In the first step, the silica nanoparticles were coated with SiC nanoparticles using high intensity ultrasonic irradiation. In a second step, 1 wt.% of as-prepared SiC/SiO2 particles were dispersed in epoxy part-A (diglycidylether of bisphenol A) using a high intensity ultrasound for 30 min at 5°C. The part-B (cycloaliphatic amine hardener) of the epoxy was then mixed with part-A- SiC/SiO2 mixture using a high-speed mechanical stirrer for 10 min. The SiC/SiO2 /epoxy resin mixture was cured at room temperature for 24 h. The SiC nanoparticles coating on SiO2 was characterized using X-ray diffraction (XRD) and high resolution transmission electron microscope (TEM). The as-prepared nanocomposite samples were characterized using thermo gravimetric analysis (TGA) and differential scanning calorimeter (DSC). Compression tests have been carried out for both nanocomposite and neat epoxy systems. The results indicated that 1 wt.% (SiC) + (SiO2) loading derived improvements in both thermal and mechanical properties when compared to the neat epoxy system.

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