Synthesis, Structural Characterization, and Thermal Properties of the Poly(methylmethacrylate)/δ-FeOOH Hybrid Material: An Experimental and Theoretical Study

Theδ-FeOOH/PMMA nanocomposites with 0.5 and 2.5 wt.% ofδ-FeOOH were prepared by grafting 3-(trimethoxysilyl)propyl methacrylate on the surface of the iron oxyhydroxide particles. The FTIR spectra of theδ-FeOOH/PMMA nanocomposites showed that the silane monomers were covalently attached to theδ-FeOOH particles. Because of the strong interaction between the PMMA andδ-FeOOH nanoparticles, the thermal stability of theδ-FeOOH/PMMA nanocomposites was improved compared to the pure PMMA. The SEM analysis conferred the size agglomerate of particles regarding the morphology of samples. The theoretical study enabled a better understanding of the interaction of the polymer with the iron oxyhydroxide. The DFT-based calculations reinforce the radical trapping mechanism of stabilization of nanocomposites; that is, Fe3+species might be able to accept electrons coming from the organic phase that decomposes via radical unzipping. The radical scavenge effect delays the weight loss of polymer.

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Study of Thermal Behaviour of EPDM/SBR Blends and Carbon Nanocoatings Deposited by Sputtering

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.875.116 ◽

2021 ◽

Vol 875 ◽

pp. 116-120

Author(s):

Muhammad Alamgir ◽

Faizan Ali Ghauri ◽

Waheed Qamar Khan ◽

Sajawal Rasheed ◽

Muhammad Sarfraz Nawaz ◽

...

Keyword(s):

Thermal Stability ◽

Weight Loss ◽

Thermogravimetric Analysis ◽

Thermal Behavior ◽

Thermal Behaviour ◽

X Ray Diffraction ◽

X Ray ◽

Thermal Stability Of

In this study, the effect of SBR concentration (10 Phr, 20 Phr & 30 Phr ) on the thermal behavior of EPDM/SBR blends was studied. Thermogravimetric analysis (TGA) was used to check weight loss of samples as function of temperature by heating upto 600°C. X-ray diffraction (XRD) was performed to determine quality and % crystallinity of the elastomer blends. It was seen that % crystallinity improved with an increase in the content of SBR in EPDM/SBR blends. TGA revealed that the thermal stability of EPDM/SBR blends has improved by 17% than neat EPDM. Carbon nano-coatings produced by sputtering have no beneficial influence on thermal behaviour of elastomers.

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Synergistic Effect of 2-Acrylamido-2-methyl-1-propanesulfonic Acid on the Enhanced Conductivity for Fuel Cell at Low Temperature

Membranes ◽

10.3390/membranes10120426 ◽

2020 ◽

Vol 10 (12) ◽

pp. 426

Author(s):

Murli Manohar ◽

Dukjoon Kim

Keyword(s):

Thermal Stability ◽

Weight Loss ◽

Fuel Cell ◽

Membrane Structure ◽

Polymer Electrolyte Membranes ◽

Aliphatic Chain ◽

Electrolyte Membranes ◽

Ft Ir ◽

Enhanced Conductivity ◽

Thermal Stability Of

This present work focused on the aromatic polymer (poly (1,4-phenylene ether-ether-sulfone); SPEES) interconnected/ cross-linked with the aliphatic monomer (2-acrylamido-2-methyl-1-propanesulfonic; AMPS) with the sulfonic group to enhance the conductivity and make it flexible with aliphatic chain of AMPS. Surprisingly, it produced higher conductivity than that of other reported work after the chemical stability was measured. It allows optimizing the synthesis of polymer electrolyte membranes with tailor-made combinations of conductivity and stability. Membrane structure is characterized by 1H NMR and FT-IR. Weight loss of the membrane in Fenton’s reagent is not too high during the oxidative stability test. The thermal stability of the membrane is characterized by TGA and its morphology by SEM and SAXS. The prepared membranes improved proton conductivity up to 0.125 Scm−1 which is much higher than that of Nafion N115 which is 0.059 Scm−1. Therefore, the SPEES-AM membranes are adequate for fuel cell at 50 °C with reduced relative humidity (RH).

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Theoretical study on thermal stability of molten salt for solar thermal power

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2013.01.023 ◽

2013 ◽

Vol 54 (1) ◽

pp. 140-144 ◽

Cited By ~ 23

Author(s):

Xiaolan Wei ◽

Qiang Peng ◽

Jing Ding ◽

Xiaoxi Yang ◽

Jianping Yang ◽

...

Keyword(s):

Thermal Stability ◽

Molten Salt ◽

Theoretical Study ◽

Thermal Power ◽

Solar Thermal ◽

Solar Thermal Power ◽

Thermal Stability Of

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ROLE OF MOLYBDENUM TRIOXIDE ON THERMAL STABILITY OF POLYANILINE NANOCOMPOSITE

International Journal of Nanoscience ◽

10.1142/s0219581x12500251 ◽

2012 ◽

Vol 11 (03) ◽

pp. 1250025

Author(s):

P. SUJA PREMA RAJINI ◽

R. MURUGESAN ◽

S. PERUMAL

Keyword(s):

Thermal Stability ◽

Weight Loss ◽

Particle Size ◽

Metal Oxide ◽

Molybdenum Trioxide ◽

Spectral Studies ◽

Average Particle ◽

Weight Loss Step ◽

The Third ◽

Thermal Stability Of

Molybdenum trioxide (MoO3) grains were coated with conducting organic polymer of polyaniline. The as-prepared nanocomposite samples were characterized by Fourier transformed infrared (FTIR) spectra, X-ray diffraction (XRD) and Thermogravimetry (TGA). The XRD curves shows that, [Formula: see text] have high crystallinity due to the presence of large number of sharp peaks. From the XRD pattern the particle size is evaluated by using Debye-Scherrer's formula and the average particle size of [Formula: see text] and [Formula: see text] nanocomposites are found to be 46 and 32 nm, respectively. This is clearly observed that the condensed particle size of nanocomposite materials is due to the insertion of metal oxide of molybdenum. The incorporation of metal oxide of MoO3 in polyaniline (Pani) is confirmed by FTIR spectral studies. After de-doping, the characteristic peaks of Pani for all the Pani materials are almost same. This is due to the leaching of metal oxide of MoO3 from Pani. From these observations it is noted that doping–dedoping can also take place in inorganic metal oxides. The thermogram showed a three-step degradation process. The first weight loss step was due to the removal of physisorbed water molecules and moisture. The second minor weight loss step was associated with the removal of dopant from Pani backbone and the slight degradation of benzenoid structure of Pani and their thermal stability is enhanced. The third weight loss step was ascribed to the degradation of quinoid form of Pani. This confirmed the thermal stability of [Formula: see text] nanocomposite system. After degradation above 1000°C, the Pani with MoO3 showed a remaining weight of 8%. This confirmed that incorporation of metal oxide in the Pani nanocomposites is 8%. The enhancement of thermal stability is due to the intercalation of Pani chains into MoO3 in first two step degradation, which is further supported by FTIR and XRD reports. The third step degradation of Pani with MoO3 nanocomposite is loosely bound in organic and inorganic part. Therefore, the organic part is easily decomposed.

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Thermal stability of Group 6 bis(cyclopentadienyl) and ethylene bridged bis(cyclopentadienyl) monocarbonyl complexes; a theoretical study

Journal of the Chemical Society Dalton Transactions ◽

10.1039/a905363h ◽

1999 ◽

pp. 3767-3770 ◽

Cited By ~ 15

Author(s):

Jennifer C. Green ◽

Christian N. Jardine

Keyword(s):

Thermal Stability ◽

Theoretical Study ◽

Group 6 ◽

Thermal Stability Of

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Thermal stability of polyurethane coating prepared by using diphenylolpropane

Butlerov Communications ◽

10.37952/roi-jbc-01/20-62-4-81 ◽

2020 ◽

Vol 62 (4) ◽

pp. 81-87

Author(s):

Indira N. Bakirova ◽

Keyword(s):

Thermal Stability ◽

Thermal Decomposition ◽

Weight Loss ◽

Elevated Temperatures ◽

Onset Temperature ◽

Phenolic Hydroxyl ◽

Hydroxyl Groups ◽

Polyurethane Coating ◽

Urethane Group ◽

Thermal Stability Of

Thermal stability of polyurethane varnish coating prepared by using diphenylolpropane, polyetherpolyol and polyisocyanate with an equimolar ratio of isocyanate and hydroxyl groups was assessed in the air. The polyurethane weight loss thermogram shows three temperature regions: I – (217-275)°С, II – (275-380)°С, and III – above 380°С. For interpreting thermogram of the polyurethane under study the model substances simulating the urethane groups of a polymer were synthesized. The substance containing the urethane group formed by phenolic hydroxyl of diphenylolpropane was shown to demonstrate relatively low thermal stability and gets broken down into isocyanate and bisphenol. Decomposition of the substance containing the urethane group formed by alcoholic hydroxyl occurs at the higher temperature. The data obtained allow interpreting the occurrence of thermal decomposition step I in TGA curve by structural changes in the blocks formed by diphenylolpropane and polyisocyanate being the least stable when exposed to elevated temperatures. The next step can be attributed to decomposition of more thermostable urethane groups formed by functional groups of oligooxypropylenetriol and polyisocyanate. Transition to the step III accompanied by severe sample weight loss due to decomposition of urethane groups is explained by thermal oxidation of oligoether units of polymer. Based on the data obtained the conclusion was made that the presence of urethane groups formed by phenolic hydroxyl of diphenylolpropane in polymer structure results in the decreased thermooxidative decomposition onset temperature of polymer. At the same time, a deceleration of thermooxidative processes due to the stabilizing effect of diphenylolpropane released at the beginning of thermal decomposition of polyurethane is observed in a high-temperature region. The proposed polyurethane coating is inferior to commercial counterparts in thermal decomposition onset temperature but superior to them in the temperature corresponding to a 50% polymer weight loss.

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