scholarly journals An Investigation on the Thermal and Solar Properties of Graphene-Coated Polyester Fabrics

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 125
Author(s):  
Gizem Manasoglu ◽  
Rumeysa Celen ◽  
Mehmet Kanik ◽  
Yusuf Ulcay
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Radiant Heat ◽  
Woven Fabrics ◽  
Radiant Heat Transfer ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Polyester Fabrics ◽  
Solar Absorbance

In this study, coatings were made with graphene nanopowder in two different thicknesses (0.1 and 0.5 mm) at three different concentrations (50, 100 and 150 g/kg) on polyester woven fabrics. The effects of the coating thickness and graphene concentration were examined with optical and scanning electron microscopy (SEM) images. The thermal stability properties of the samples were also evaluated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Thermal conductivity was evaluated with two different principles: contact and radiant heat transfer, according to JIS R 2618 and EN ISO 6942, respectively. Solar measurements were performed with a Shimadzu UV-3600 Plus spectrophotometer. The graphene coating improved the thermal stability of the polyester fabrics. The solar absorbance value increased by 80% compared to reference fabrics, and reached approximately 90%. One of the important results was that the thermal conductivity coefficient increased by 87% and 262% for the two coating thicknesses, respectively.

Synthesis and thermal stability studies of polyaniline/silver nanocomposite based on reduction of silver ions using polyaniline

2011 ◽  
Vol 23 (7) ◽  
pp. 513-517 ◽  
Author(s):  
Mohsen Ghorbani ◽  
Mohammad Soleimani Lashkenari ◽  
Hossein Eisazadeh
Keyword(s):  
Thermal Stability ◽  
Chemical Structure ◽  
Aqueous Media ◽  
Silver Ions ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Stability Studies ◽  
Scanning Calorimetry ◽  
Chemical Polymerization ◽  
Silver Nanocomposite

This study investigated the preparation and properties of polyaniline/silver (PAn/Ag2O) nanocomposite in aqueous media by chemical polymerization of aniline in the presence of ammonium peroxydisulphate as an oxidant. The products were investigated in terms of morphology, chemical structure, thermal stability and thermal degradation using scanning electron microscopy, Fourier transform infrared, thermal gravimetric analysis and differential scanning calorimetry, respectively. The results indicated that the properties of products were dependent on the nanocomposite structure.

The Polyurethane Foams Based on Melamine-formaldehyde-cyclohexanone Resins

2017 ◽  
Vol 36 (1) ◽  
pp. 35-50 ◽  
Author(s):  
Dorota Głowacz-Czerwonka
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Differential Thermal Analysis ◽  
Compression Strength ◽  
Polyurethane Foams ◽  
Diphenylmethane Diisocyanate ◽  
Melamine Formaldehyde ◽  
Scanning Calorimetry

The conditions and methods for obtaining polyurethane foams based on melamine-formaldehyde-cyclohexanone resins are presented These foams were obtained from melamine solution in reactive solvents based on cyclohexanone and 4,4′-diphenylmethane diisocyanate. Some properties of obtained polyurethane foams were examined, e.g. apparent density, water absorbing capacity, dimensional stability, thermal conductivity, thermal stability, flammability and compression strength. Also a thermal analysis using the differential thermal analysis and differential scanning calorimetry methods was carried out. Polyurethane foams with increased thermal stability were obtained.

Heat transfer

2019 ◽  
Author(s):  
Владимир Чередниченко ◽  
Vladimir Cherednichenko ◽  
Валерий Синицын ◽  
Valeriy Sinicyn ◽  
Александр Алиферов ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Physical Interpretation ◽  
Electrical Engineering ◽  
Thermal Power ◽  
Radiant Heat ◽  
Radiant Heat Transfer ◽  
Main Attention ◽  
Methods Of Calculation ◽  
Wide Range

The basic provisions of the theory of heat transfer, including thermal conductivity, convective and radiant heat transfer. The information about the methods of calculation of heat transfer in power engineering, electrical engineering, electromechanics and electrical engineering is given. The first edition was published in 2004, the Material of the second edition in part updated and supplemented, the main attention is paid to the physical interpretation of the issues involved. The manual can be useful for students of thermal power, Electromechanical, electrotechnological and engineering specialties, as well as a wide range of engineering and technical workers.

Sequence Effects on Properties of the Poly(p-phenylene terephthalamide)-based Macroinitiators and their Comb-like Copolymers Grafted by Polystyrene Side Chains

2014 ◽  
Vol 67 (1) ◽  
pp. 39 ◽  
Author(s):  
Shuming Du ◽  
Jie Zhang ◽  
Yan Guan ◽  
Xinhua Wan
Keyword(s):  
Thermal Stability ◽  
Graft Copolymers ◽  
Side Chains ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Terephthaloyl Chloride ◽  
Discernible Effect ◽  
Sequence Effects ◽  
Concentrated Sulfuric Acid

Two poly(p-phenylene terephthalamide) (PPTA)-based macroinitiators with random and alternate sequences, i.e. poly(p-phenylene terephthalamide)-ran-poly[p-phenylene (2,2,6,6-tetramethylpiperidinyl-1-oxy)terephthalamide)] (CPPTA-ran) and poly(p-phenylene terephthalamide)-alt-poly[p-phenylene (2,2,6,6-tetramethylpiperidinyl-1-oxy)terephthalamide)] (CPPTA-alt), were prepared via copolycondensation of terephthaloyl chloride, 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO)-functionalized terephthaloyl chloride, and p-phenylenediamine. The graft copolymers consisting of rigid PPTA backbones and polystyrene side chains were obtained by nitroxide-mediated radical polymerization. Both macroinitiators and graft copolymers were characterized by thermal gravimetric analysis, differential scanning calorimetry, wide-angle X-ray diffraction, and polarized optical microscopy. The regular incorporation of the TEMPO-containing co-unit gives rise to remarkable effects on the thermal stability, lyotropic liquid crystallinity, and macromolecular packing in bulk. CPPTA-alt shows better thermal stability and more ordered intermolecular structure than CPPTA-ran. The former generates a nematic phase at a concentration of 18 wt-% in concentrated sulfuric acid, whereas the latter does so at a concentration of 12 wt-%. For the graft copolymers, the alternative main chains exhibit sharper diffraction than the random ones. However, the sequence change exerts no discernible effect on other properties.

Polymer nanocomposites reinforced with C60 fullerene: effect of hydroxylation

2011 ◽  
Vol 45 (25) ◽  
pp. 2595-2601 ◽  
Author(s):  
Tsuyoshi Saotome ◽  
Ken Kokubo ◽  
Shogo Shirakawa ◽  
Takumi Oshima ◽  
H. Thomas Hahn
Keyword(s):  
Thermal Stability ◽  
Thermo Gravimetric Analysis ◽  
Nanocomposite Films ◽  
Light Transmittance ◽  
C60 Fullerene ◽  
Partial Hydrolysis ◽  
Poly Vinyl Alcohol ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

Novel nanocomposite films of polycarbonate (PC) with fullerene derivatives, such as pristine fullerene C60 and polyhydroxylated-fullerenes, C60(OH)12 and C60(OH)36, were prepared. The optical, thermal, and mechanical properties of the composites were measured. Nanocomposite films of poly (vinyl alcohol) (PVA) with C60(OH)36 were prepared as a reference to show how improved dispersion of the nanofiller affects the overall transparency of the composites. Ultraviolet-visible spectroscopy showed that the addition of hydroxylated fullerenes did not affect visible light transmittance of the films significantly in the range of 400–800 nm. Differential scanning calorimetry (DSC) and thermo–gravimetric analysis (TGA) measurements showed the increased thermal stability of PC/C60(OH)12 film as compared to pristine PC film. This phenomenon was explained by the rigid polymer interphase regions formed around C60(OH)12 due to the plausible hydrogen bonding and hydrophobic interaction. On the other hand, the lower thermal stability of PC–C60(OH)36 was assumed to be caused by large agglomeration of the C60(OH)36 particles and the partial hydrolysis of the polycarbonate matrix. Tensile testing of the composites showed reduction in elongation at break and yield tensile strength. These results may be caused by the particle agglomerations which act as the initiation points for cracks.

Synthesis of Flame-retardant Phosphaphenanthrene Derivatives with High Phosphorus Contents

2014 ◽  
Vol 67 (11) ◽  
pp. 1688 ◽  
Author(s):  
Jinyun Zheng ◽  
Yujian Yu ◽  
Lulu Zhang ◽  
Xiaomin Zhen ◽  
Yufen Zhao
Keyword(s):  
Thermal Stability ◽  
Flame Retardant ◽  
High Resolution Mass Spectrometry ◽  
Lithium Ion ◽  
Decomposition Temperature ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
High Phosphorus ◽  
Phosphorylation Reaction ◽  
Flame Retardant Properties

Two novel types of phosphate derivatives of phosphaphenanthrene with a high phosphorus content were prepared by phosphorylation reaction between either 2-(6-oxido-6H-dibenz<c,e><1,2>oxaphosphorin-6-yl)-methanol (ODOPM) or 2-(6-oxido-6H-dibenz<c,e><1,2>oxaphosphorin-6-yl)-1,4-benzenediol (ODOPB) and dialkyl phosphoryl chloride. The structures of all compounds were characterised by 1H NMR, 13C NMR, 31P NMR, Fourier transform infrared spectroscopy, and high-resolution mass spectrometry. The thermal stability of representative compounds was determined by thermal gravimetric analysis and differential scanning calorimetry. The results showed that the compounds have excellent resistance to oxidation, high thermal stability with an onset decomposition temperature above 200°C, and a high char yield over 25 %, owing to the high P content. The representative compound was added to conventional electrolytes of lithium-ion batteries as flame retardant additive, and the self-extinguishing time and ionic conductivity were measured. The result showed that the compounds have effective flame retardant properties.

Investigating the Biodegradability and Physical Properties of Starch Derived Bioplastic Films Reinforced with Nanosilica

2018 ◽  
Vol 18 (06) ◽  
pp. 1850037 ◽  
Author(s):  
Anagha Ashok ◽  
C. R. Rejeesh
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Thermo Gravimetric Analysis ◽  
Thermoplastic Starch ◽  
High Rate ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Pilot Investigation ◽  
Nanosilica Particles ◽  
Xrd Techniques

This study is a pilot investigation on the effect of using nanosilica for reinforcing thermoplastic starch-based bioplastic films. An arbitrary 0.2[Formula: see text]wt.% of nanosilica particles were used to reinforce starch derived bioplastic materials and were further investigated for potential benefits. Nanosilica was extracted from rice husk and was characterized using methods like Fourier transform infrared spectroscopy (FTIR) technique and Brunauer–Emmett–Teller (BET) method. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques were used to determine the structure of nanosilica crystals. Scanning electron microscopy (SEM) technique was used to study the surface topography and composition of nano ‘silica. Both raw and reinforced bioplastic films were tested for thermal stability using thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) tests and their performance was compared. Mechanical properties were compared using tensile and tear tests and biodegradability was assessed through enzymatic degradation analysis. It was found that the presence of nanosilica improved the bonding of polymer matrix and in turn increased the thermal stability and tear strength. Nanosilica reinforced matrix resulted in the increase of surface area than raw bioplastic matrix, which lead to high rate of enzymatic reactivity and degradation rate.

scholarly journals STUDY OF THE KINETICS OF THERMAL DEGRADATION OF UNSATURATED POLYESTER AND POLYESTER/ SILICA NANOPARTICLES COMPOSITES BY TGA AND DSC ANALYSIS TECHNIQUES

2020 ◽  
Vol 17 (35) ◽  
pp. 437-448
Author(s):  
Ahmed Jadah FARHAN
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Silica Nanoparticles ◽  
Thermal Gravimetric Analysis ◽  
Unsaturated Polyester ◽  
Engineering Properties ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Research Activity ◽  
Scanning Calorimetry

Composites are multi-phase materials that have superior engineering properties; the combination of their constituent phases achieves these properties. Nanoparticle-reinforced polymeric composites (NPCs) are new types of composites that have attracted a lot of attention recently and rapidly emerging as a multidisciplinary research activity whose results could widen the applications of polymers to the benefit of many different industries. The aim of research to analyze the effect of adding different percentages (10, 20, and 30%) of silica nanoparticles into unsaturated polyester (UPE) and identification of the thermal stability and decomposition kinetics for them. In this research, the nanocomposites were prepared from unsaturated polyester (UPE) mixed with different percentages (10, 20, and 30%) of silica nanoparticles. Thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) curves were obtained from the thermal degradation computed by using the Coats-Redfern. The kinetic and thermodynamic parameters were studied for all specimens were presented an excellent linear correlation coefficient close to unity using Minitab 16. Experimental work was showed that the degradation of composites obtained from the thermal gravimetric analysis was slower than the pure UPE. The enhancement of thermal stability was attributed to silica content. Also, the result showed that the decomposition under the oxidative environment for the pure UPE was much faster than the inert environment.

scholarly journals Evaluation of LDPE Degradation Under Controlled Composting

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
S. Singh ◽  
S. Shankar ◽  
Shikha .
Keyword(s):  
Major Change ◽  
Natural Ecosystem ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
X Ray ◽  
Polyethylene Films ◽  
Scanning Electron

The compost burial test was performed to determine the degradation of commercially available low-density polyethylene in natural compost for a period of six months. Biodegradability of polyethylene films in compost was monitored using scanning electron microscopy (SEM), Energy dispersive X-Ray, Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and weight reduction analysis. After six months of compost exposure, a major change over the surface of LDPE was observed. SEM images clearly showed the exfoliation and cracks on the film leading to degradation. The other analysis also showed a change in the thermal properties and crystallinity of the LDPE films. The composting method could prove to be the reliable and ecological method of degrading plastic waste without hindering the natural ecosystem.

scholarly journals VO2(B) conversion to VO2(A) and VO2(M) and their oxidation resistance and optical switching properties

2016 ◽  
Vol 34 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Yifu Zhang
Keyword(s):  
Thermal Stability ◽  
Oxidation Resistance ◽  
Optical Switching ◽  
Variable Temperature ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Hydrothermal Route ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Air Atmosphere

AbstractVanadium dioxide VO2 has been paid in recent years increasing attention because of its various applications, however, its oxidation resistance properties in air atmosphere have rarely been reported. Herein, VO2(B) nanobelts were transformed into VO2(A) and VO2(M) nanobelts by hydrothermal route and calcination treatment, respectively. Then, we comparatively studied the oxidation resistance properties of VO2(B), VO2(A) and VO2(M) nanobelts in air atmosphere by thermo-gravimetric analysis and differential thermal analysis (TGA/DTA). It was found that the nanobelts had good thermal stability and oxidation resistance below 341 °C, 408 °C and 465 °C in air, respectively, indicating that they were stable in air at room temperature. The fierce oxidation of the nanobelts occurred at 426, 507 and 645 °C, respectively. The results showed that the VO2(M) nanobelts had the best thermal stability and oxidation resistance among the others. Furthermore, the phase transition temperatures and optical switching properties of VO2(A) and VO2(M) were studied by differential scanning calorimetry (DSC) and variable temperature infrared spectra. It was found that the VO2(A) and VO2(M) nanobelts had outstanding thermochromic character and optical switching properties.

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