Effect of surface treatment on thermal stability of the hemp-PLA composites: Correlation of activation energy with thermal degradation

This study investigates the effect of alkali treatment on the thermal degradation and thermal stability of hemp, and hemp reinforced Poly Lactic Acid (PLA) composites. The results indicate that thermal stability of the composites decreases with increase in fiber loading due to the lower thermal stability of hemp compared to PLA matrix. The alkali treated composites have shown higher thermal stability in comparison to untreated hemp-PLA composites due to the increased fiber-matrix bonding.

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Study on Flammability Characteristics and Thermal Stability of Flame-Retardant PA Fibers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.631-632.277 ◽

2013 ◽

Vol 631-632 ◽

pp. 277-280 ◽

Cited By ~ 2

Author(s):

Jian Min Zhao ◽

Li Wen Tan

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Thermal Degradation ◽

Flame Retardant ◽

Sem Images ◽

Tg Analysis ◽

Flammability Characteristics ◽

Degradation Activation Energy ◽

Thermal Stability Of ◽

Better Than

The flammability characteristics and thermal stability were studied based on LOI, TG analysis and SEM tests. The results revealed that the additive flame retardant enhanced the flame retardancy of PA. The TG analysis showed that the thermal stability of flame-retardant PA fibers was better than PA fibers, because flame-retardant PA fibers got higher residue content and thermal degradation activation energy. The SEM images indicated the flame retardant residues were infusible, which can impede the molten dropping of PA fibers during combustion.

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Thermal and kinetic analysis of pure and contaminated ionic liquid: 1-butyl-2.3-dimethylimidazolium chloride (BDMIMCl)

Polish Journal of Chemical Technology ◽

10.1515/pjct-2016-0038 ◽

2016 ◽

Vol 18 (2) ◽

pp. 122-125 ◽

Cited By ~ 2

Author(s):

Ayyaz Muhammad

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Thermal Decomposition ◽

Ionic Liquid ◽

Thermal Degradation ◽

Kinetic Analysis ◽

Kinetic Parameters ◽

Process Design ◽

Research Work ◽

Thermal Stability Of

Abstract In this research work, thermal decomposition and kinetic analysis of pure and contaminated imidazolium based ionic liquid (IL) has been investigated. As thermal decomposition and kinetics evaluation plays a pivotal role in effective process design. Therefore, thermal stability of pure 1-butyl-2,3-dimethylimidazolium chloride (BDMIMCl) was found to be higher than the sample of IL with the addition of 20% (wt.) NH4Cl as an impurity. The activation energy of thermal degradation of IL and other kinetic parameters were determined using Coats Redfern method. The activation energy for pure IL was reduced in the presence of NH4Cl as contaminant i.e., from 58.7 kJ/mol to 46.4 kJ/mol.

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Flammability and Thermal Degradation of Polystyrene/Cadmium Sulfate Nanocomposites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.820.84 ◽

2013 ◽

Vol 820 ◽

pp. 84-87

Author(s):

Zheng Zhou Wang ◽

Charles A. Wilkie

Keyword(s):

Thermal Stability ◽

Thermal Degradation ◽

Cone Calorimeter ◽

Cds Nanoparticles ◽

Solvothermal Process ◽

Cadmium Sulfate ◽

Peak Heat Release Rate ◽

Microscale Combustion Calorimeter ◽

Combustion Calorimeter ◽

Thermal Stability Of

Cadmin sulfate nanoparticles, hollow sphere (CdS-HS) and rode (CdS-NR) were synthesized by ultrasonic and solvothermal process, respectively. The effect of the two kinds of nanoparticles on flammability of polystyrene was investigated using cone calorimeter (Cone) and microscale combustion calorimeter (MCC). Cone data indicate that the incorporation of 1% CdS nanoparticles leads to a about 20% reduction in the peak heat release rate (PHRR) compared to the pure PS; CdS-NR is more efficient in reducing the PHRR proved by both Cone and MCC results. The TG results show that the addition of the nanoparticles mainly increases thermal stability of PS at high temepratures.

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Meyer-Neldel Rule on thermal stability parameters (trap depth and frequency factor) of luminescence signals in quartz

10.5194/egusphere-egu21-10775 ◽

2021 ◽

Author(s):

Zuzanna Kabacińska ◽

Alida Timar-Gabor ◽

Benny Guralnik

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Hydrogen Diffusion ◽

Dose Range ◽

Accurate Determination ◽

Frequency Factor ◽

Proton Conduction ◽

High Dose ◽

Compensation Law ◽

Thermal Stability Of

Thermally activated processes can be described mathematically by the Arrhenius equation. The Meyer-Neldel Rule (MNR), or compensation law, linearly relates the pre-exponent term to the logarithm of the excitation enthalpy for processes that are thermally driven in an Arrhenian manner. This empirical rule was observed in many areas of materials science, in physics, chemistry, and biology. In geosciences it was found to uphold in hydrogen diffusion (Jones 2014a) and proton conduction (Jones 2014b) in minerals.Trapped charge dating methods that use electron spin resonance (ESR) or optically or thermally stimulated luminescence (OSL and TL) are based on the dose-dependent accumulation of defects in minerals such as quartz and feldspar. The thermal stability of these defects in the age range investigated is a major prerequisite for accurate dating, while the accurate determination of the values of the trap depths and frequency factors play a major role in thermochronometry applications.&#160;The correlation of kinetic parameters for diffusion has been very recently established for irradiated oxides (Kotomin et al. 2018). A correlation between the activation energy and the frequency factor that satisfied the Meyer&#8211;Neldel rule was reported when the thermal stability of [AlO4/h+]0 and [TiO4/M+]0 ESR signals in quartz was studied as function of dose (Benzid and Timar-Gabor 2020). Here we compiled the optically stimulated luminescence (OSL) data published so far in this regard, and investigated experimentally the thermal stability of OSL signals for doses ranging from 10 to 10000 Gy in sedimentary quartz samples. We report a linear relationship between the natural logarithm of the preexponent term (the frequency factor) and the activation energy E, corresponding to a Meyer-Neldel energy of 45 meV, and a deviation from first order kinetics in the high dose range accompanied by an apparent decrease in thermal stability. The implications of these observations and the atomic and physical mechanisms are currently studied.&#160;ReferencesBenzid, K., Timar Gabor, A. 2020. The compensation effect (Meyer&#8211;Neldel rule) on [AlO4/h+]0 and [TiO4/M+]0 paramagnetic centers in irradiated sedimentary quartz. AIP Advances 10, 075114.Kotomin, E., Kuzovkov, V., Popov, A. I., Maier, J., and Vila, R. 2018. Anomalous kinetics of diffusion-controlled defect annealing in irradiated ionic solids. J. Phys. Chem. A 122(1), 28&#8211;32Jones, A. G. (2014a), Compensation of the Meyer-Neldel Compensation Law for H diffusion in minerals, Geochem. Geophys. Geosyst., 15, 2616&#8211;2631Jones, A. G. (2014b), Reconciling different equations for proton conduction using the Meyer-Neldel compensation rule, Geochem. Geophys. Geosyst., 15, 337&#8211;349

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Non-isothermal crystallization and thermal degradation kinetics of MXene/linear low-density polyethylene nanocomposites

e-Polymers ◽

10.1515/epoly-2017-0017 ◽

2017 ◽

Vol 17 (5) ◽

pp. 373-381 ◽

Cited By ~ 12

Author(s):

Xinxin Cao ◽

Mengqi Wu ◽

Aiguo Zhou ◽

You Wang ◽

Xiaofang He ◽

...

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Thermal Degradation ◽

Isothermal Crystallization ◽

Degradation Kinetics ◽

Thermal Degradation Kinetics ◽

Low Density Polyethylene ◽

Low Density ◽

Linear Low Density Polyethylene ◽

Kinetics Of

AbstractA novel two-dimensional material MXene was used to synthesize nanocomposites with linear low-density polyethylene (LLDPE). The influence of MXene on crystallization and thermal degradation kinetics of LLDPE was investigated. Non-isothermal crystallization kinetics was investigated by using differential scanning calorimetry (DSC). The experimental data was analyzed by Jeziorny theory and the Mo method. It is found that MXene acted as a nucleating agent during the non-isothermal crystallization process, and 2 wt% MXene incorporated in the nanocomposites could accelerate the crystallization rate. Findings from activation energy calculation for non-isothermal crystallization came to the same conclusion. Thermal gravity (TG) analysis of MXene/LLDPE nanocomposites was conducted at different heating rates, and the TG thermograms suggested the nanocomposites showed an improvement in thermal stability. Apparent activation energy (Ea) of thermal degradation was calculated by the Kissinger method, and Ea values of nanocomposites were higher than that of pure LLDPE. The existence of MXene seems to lead to better thermal stability in composites.

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Thermal Stability of Ultrafine-Grained Pure Titanium Processed by High-Pressure Torsion

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1016.338 ◽

2021 ◽

Vol 1016 ◽

pp. 338-344

Author(s):

Wan Ji Chen ◽

Jie Xu ◽

De Tong Liu ◽

De Bin Shan ◽

Bin Guo ◽

...

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Grain Size ◽

High Pressure ◽

Annealing Temperature ◽

High Pressure Torsion ◽

Stored Energy ◽

Ultrafine Grained ◽

Average Grain Size ◽

Thermal Stability Of

High-pressure torsion (HPT) was conducted under 6.0 GPa on commercial purity titanium up to 10 turns. An ultrafine-grained (UFG) pure Ti with an average grain size of ~96 nm was obtained. The thermal properties of these samples were studied by using differential scanning calorimeter (DSC) which allowed the quantitative determination of the evolution of stored energy, the recrystallization temperatures, the activation energy involved in the recrystallization of the material and the evolution of the recrystallized fraction with temperature. The results show that the stored energy increases, beyond which the stored energy seems to level off to a saturated value with increase of HPT up to 5 turns. An average activation energy of about 101 kJ/mol for the recrystallization of 5 turns samples was determined. Also, the thermal stability of the grains of the 5 turns samples with subsequent heat treatments were investigated by microstructural analysis and Vickers microhardness measurements. It is shown that the average grain size remains below 246 nm when the annealing temperature is below 500 °C, and the size of the grains increases significantly for samples at the annealing temperature of 600 °C.

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The Use of POSS-Based Nanoadditives for Cable-Grade PVC: Effects on its Thermal Stability

Polymers ◽

10.3390/polym11071105 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1105 ◽

Cited By ~ 5

Author(s):

Palin ◽

Rombolà ◽

Milanesio ◽

Boccaleri

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Thermogravimetric Analysis ◽

Thermal Degradation ◽

Additive Effects ◽

Poly Vinyl Chloride ◽

The Family ◽

Mechanical Performances ◽

Oligomeric Silsesquioxane ◽

Thermal Stability Of

Plasticized–Poly(vinyl chloride) (P-PVC) for cables and insulation requires performances related to outdoor, indoor and submarine contexts and reduction of noxious release of HCl-containing fumes in case of thermal degradation or fire. Introducing suitable nanomaterials in polymer-based nanocomposites can be an answer to this clue. In this work, an industry-compliant cable-grade P-PVC formulation was added with nanostructured materials belonging to the family of Polyhedral Oligomeric Silsesquioxane (POSS). The effects of the nanomaterials, alone and in synergy with HCl scavenging agents as zeolites and hydrotalcites, on the thermal stability and HCl evolution of P-PVC were deeply investigated by thermogravimetric analysis and reference ASTM methods. Moreover, hardness and mechanical properties were studied in order to highlight the effects of these additives in the perspective of final industrial uses. The data demonstrated relevant improvements in the thermal stability of the samples added with nanomaterials, already with concentrations of POSS down to 0.31 phr and interesting additive effects of POSS with zeolites and hydrotalcites for HCl release reduction without losing mechanical performances.

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Synthesis of Fe-rich Fe–Al nanocrystalline solid solutions using ball milling

Journal of Materials Research ◽

10.1557/jmr.1999.0238 ◽

1999 ◽

Vol 14 (5) ◽

pp. 1760-1770 ◽

Cited By ~ 18

Author(s):

H. G. Jiang ◽

H. M. Hu ◽

E. J. Lavernia

Keyword(s):

Heat Treatment ◽

Activation Energy ◽

Thermal Stability ◽

Intermetallic Compound ◽

Ball Milling ◽

Microstructural Evolution ◽

Solid Solutions ◽

Al Alloys ◽

Time Intervals ◽

Thermal Stability Of

The synthesis of nanocrystalline Fe, Fe–4 wt% Al, and Fe–10 wt% Al solid solutions by SPEX ball milling has been studied. The microstructural evolution during ball milling, as well as subsequent heat treatment, has been characterized. The results demonstrate that ball milling promotes the formation of αFe–4 wt% Al and αFe–10 wt% Al solid solutions by reducing the activation energy of these alloys and generating thermal energy during this process. For Fe–10 wt% Al powders milled for various time intervals up to approximately 20 min, the FeAl intermetallic compound is formed. For alloys annealed at temperatures ranging from 600 to 1000 °C, the addition of 10 wt% Al to Fe significantly enhances the thermal stability of the nanocrystalline Fe–Al alloys. Interestingly, the addition of Al within the range of 4–10 wt% seems to have little effect on the thermal stability of these alloys annealed under the same conditions. Also, the thermal stability improves for alloys milled in air as opposed to those processed using Ar.

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Epoxy Cured with Anhydride Terminated Polydimethylsiloxane: Cure Kinetics and Thermal Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.261 ◽

2011 ◽

Vol 415-417 ◽

pp. 261-264

Author(s):

Yuan Ren ◽

Zheng Xi ◽

Wen Jun Gan ◽

Liang Zhang ◽

Jing Zhang ◽

...

Keyword(s):

Activation Energy ◽

Thermal Stability ◽

Thermal Properties ◽

Succinic Anhydride ◽

Cure Kinetics ◽

Diglycidyl Ether ◽

Scanning Calorimetry ◽

Thermogravimetric Analyses ◽

Isothermal Measurements ◽

Thermal Stability Of

A siloxane-containing dianhydride, succinic anhydride terminated polydimethylsiloxane (DMS-Z21) was selected to cure diglycidyl ether of bisphenol-A based epoxy resin (DGEBA). The cure kinetics and thermal properties were investigated by nonisothermal and isothermal differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA), respectively. The activation energy (Ea) of the curing reaction was obtained based on the methods of Kissinger and isothermal measurements. The results of the thermogravimetric analyses of the DGEBA/DMS-Z21 system showed that the thermal stability of the DGEBA/DMS-Z21 system was slightly higher than the DGEBA/MeTHPA system.

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