Kinetics of Non-Isothermal Degradation of PFA

2012 ◽  
Vol 268-270 ◽  
pp. 138-142
Author(s):  
Zhi Hong Guo ◽  
Pei Jie Lin ◽  
Qing Yan Xu ◽  
Qun Shao ◽  
Yan Ping Wang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermal Degradation ◽  
Melt Processing ◽  
Kissinger Method ◽  
Secondary Reaction ◽  
Ozawa Method ◽  
Degradation Activation Energy ◽  
Degradation Reaction ◽  
Kinetics Of

Thermal stability can reflect the thermal degradation speed of polymers during the melt processing. In this paper, we used Kissinger, Flynn-Wall-Ozawa and Coats-Redfern method to study the kinetics of non-isothermal degradation of PFA. The thermal degradation activation energy obtained from the Kissinger method, Flynn-Wall-Ozawa method and Coats-Redfern method is 228.5 kJ/mol, 213.9 kJ/mol and 237.4 kJ/mol respectively. The Flynn-Wall-Ozawa method indicates the thermal degradation reaction PFA is a secondary reaction.

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

e-Polymers ◽  
2017 ◽  
Vol 17 (5) ◽  
pp. 373-381 ◽  
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.

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

2013 ◽  
Vol 631-632 ◽  
pp. 277-280 ◽  
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.

scholarly journals Kinetics Study of Thermal Degradation of Resin Derived from Salicylaldehyde, Ethylenediamine and Formaldehyde

2010 ◽  
Vol 7 (2) ◽  
pp. 564-568 ◽  
Author(s):  
Dhanraj. T. Masram ◽  
N. S. Bhave ◽  
K. P. Kariya
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Free Energy ◽  
Thermal Degradation ◽  
Frequency Factor ◽  
Entropy Change ◽  
Energy Change ◽  
Kinetics Study ◽  
Degradation Studies ◽  
Kinetics Of

The present paper reports the synthesis and kinetics of thermal degradation studies of resin salicylicldehyde -ethylenediamine -formaldehyde (SdEDF) derived by the condensation of salicylicldehyde and ethylenediamine with formaldehyde in the presence of catalyst hydrochloric acid in 1:1:2 molar proportions of reactants. Detailed thermal degradation studies of the SdEDF resin has been carried out to ascertain its thermal stability. Thermal degradation curve has been discussed in order to determine their mode of decomposition, order of reaction, apparent activation energy, frequency factor, free energy change, entropy change, and apparent energy change. Freeman - Carroll and Sharp- Wentworth methods have been applied for the calculation of kinetic parameters while the data from the Freeman - Carroll methods have been used to determine various thermodynamic parameters.

Thermal degradation kinetics of oxo-degradable PP/PLA blends

2018 ◽  
Vol 39 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Dev K. Mandal ◽  
Haripada Bhunia ◽  
Pramod K. Bajpai
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Kinetic Parameters ◽  
Degradation Kinetics ◽  
Nitrogen Atmosphere ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Kinetics Of

AbstractIn this article, the influence of polylactide and pro-oxidant on the thermal stability, degradation kinetics, and lifetime of polypropylene has been investigated using thermogravimetric analysis under nitrogen atmosphere at four different heating rates (i.e. 5, 10, 15, and 20°C/min). The kinetic parameters of degradation were studied over a temperature range of 30–550°C. The derivative thermogravimetric curves have indicated single stage and two stage degradation processes. The activation energy was evaluated by using the Kissinger, Kim-Park, and Flynn-Wall methods under the nitrogen atmosphere. The activation energy value of polypropylene was much higher than that of polylactide. Addition of polylactide and pro-oxidant in polypropylene decreased the activation energy. The lifetime of polypropylene has also decreased with the addition of polylactide and pro-oxidant.

Thermal degradation behaviours of flame-retardant polycarbonate containing potassium diphenyl sulfonate and polymethylphenylsilsesquioxane

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Jiangbo Wang ◽  
Zhong Xin
Keyword(s):  
Activation Energy ◽  
Thermal Degradation ◽  
Kinetic Analysis ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Final Stage ◽  
Flame Retardants ◽  
Lower Degree ◽  
Kissinger Method ◽  
Ozawa Method

AbstractPotassium diphenyl sulfonate (KSS) and polymethylphenyl silsesquioxane (PMPSQ) were proved to be effective flame retardants for PC by the LOI test and UL-94 measurements. The thermal degradation behaviours were investigated by TGA and flame-retardant mechanism of KSS/PMPSQ/PC system was studied by the kinetic analysis methods including Kissinger method and Flynn- Wall-Ozawa method. The results showed that the activation energies of flameretardant PC (FRPC) were lower than that of pure PC at lower degree of conversion, which indicated that the KSS and PMPSQ both promoted the thermal degradation of PC in the early and middle stages. Flynn-Wall-Ozawa method further revealed that the addition of the flame retardant PMPSQ increased the activation energy of FRPC thermal degradation in the final stage, which illustrated that the PMPSQ stabilized the char residues and improved the flame retardancy of FRPC in the thermal degradation. Therefore, the improved flame-retardant behaviours of KSS and PMPSQ on PC were achieved.

scholarly journals Understanding thermal decomposition kinetics of flame-retardant thermoset polylactic acid

RSC Advances ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 3128-3139 ◽  
Author(s):  
Yihan Li ◽  
Zhe Qiang ◽  
Xie Chen ◽  
Jie Ren
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Thermal Degradation ◽  
Flame Retardant ◽  
Polylactic Acid ◽  
Decomposition Kinetics ◽  
Ozawa Method ◽  
Local Activation ◽  
Local Activation Energy ◽  
Kinetics Of

The Flynn–Wall–Ozawa method was applied to study the local activation energy of flame retardant thermoset PLA, and the results showed that with an increase of conversion of thermal degradation, the local activation energy was increased slowly.

Thermal Degradation Kinetics of Poly(Arylene Ether Nitrile) and its Crosslinked Polymer

2011 ◽  
Vol 284-286 ◽  
pp. 1917-1924 ◽  
Author(s):  
Jia Chun Zhong ◽  
Jian Yang ◽  
Hai Long Tang ◽  
Xiao Bo Liu
Keyword(s):  
Activation Energy ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Decomposition Temperature ◽  
Thermal Degradation Kinetics ◽  
Ozawa Method ◽  
Initial Decomposition Temperature ◽  
Solid State Decomposition ◽  
Friedman Method ◽  
Kinetics Of

The kinetics of the thermal degradation of Polyarylene ether natriles (PEN) (crosslinked and uncrosslinked) were investigated by thermogravimetric analysis (TGA). The corresponding kinetic parameters of PEN were determined using Flynn–Wall–Ozawa method and Friedman method, respectively. Satava method was also used to discuss the probable degradation mechanisms of PEN. The results showed that the activation energy obtained from Flynn–Wall–Ozawa method was in good agreement with the value obtained from Friedman method. The solid-state decomposition mechanisms of PEN and crosslinked PEN were A2 type (nucleation and growth) and R2 type (phase boundary controlled reaction), respectively. The activation energy and initial decomposition temperature of crosslinked PEN were higher than that of PEN, which indicates that crosslinking treatment is effective to enhance the thermal stability of PEN.

Thermal degradation kinetics of Opuntia Ficus Indica flour and talc-filled poly (lactic acid) hybrid biocomposites by TGA analysis

2021 ◽  
pp. 002199832110082
Author(s):  
Azzeddine Gharsallah ◽  
Abdelheq Layachi ◽  
Ali Louaer ◽  
Hamid Satha
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Degradation Mechanism ◽  
Melt Processing ◽  
Thermal Degradation Kinetics ◽  
Poly Lactic Acid ◽  
Opuntia Ficus Indica ◽  
Model Free

This paper reports the effect of lignocellulosic flour and talc powder on the thermal degradation behavior of poly (lactic acid) (PLA) by thermogravimetric analysis (TGA). Lignocellulosic flour was obtained by grinding Opuntia Ficus Indica cladodes. PLA/talc/ Opuntia Ficus Indica flour (OFI-F) biocomposites were prepared by melt processing and characterized using Wide-angle X-ray scattering (WAXS) and Scanning Electron Microscope (SEM). The thermal degradation of neat PLA and its biocomposites can be identified quantitatively by solid-state kinetics models. Thermal degradation results on biocomposites compared to neat PLA show that talc particles at 10 wt % into the PLA matrix have a minor impact on the thermal stability of biocomposites. Loading OFI-F and Talc/OFI-F mixture into the PLA matrix results in a decrease in the maximum degradation temperature, which means that the biocomposites have lower thermal stability. The activation energies (Ea) calculated by the Flynn Wall Ozawa (FWO) and Kissinger Akahira Sunose (KAS) model-free approaches and by model-fitting (Kissinger method and Coats-Redfern method) are in good agreement with one another. In addition, in this work, the degradation mechanism of biocomposites is proposed using Coats-Redfern and Criado methods.

scholarly journals Thermal Degradation Kinetics and Modeling Study of Ultra High Molecular Weight Polyethylene (UHMWP)/Graphene Nanocomposite

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1597
Author(s):  
Iman Jafari ◽  
Mohamadreza Shakiba ◽  
Fatemeh Khosravi ◽  
Seeram Ramakrishna ◽  
Ehsan Abasi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Thermal Degradation ◽  
High Molecular Weight ◽  
Degradation Kinetics ◽  
Graphene Nanosheets ◽  
Thermal Degradation Kinetics ◽  
Graphene Nanocomposites ◽  
Kinetics Of ◽  
Ultra High Molecular Weight

The incorporation of nanofillers such as graphene into polymers has shown significant improvements in mechanical characteristics, thermal stability, and conductivity of resulting polymeric nanocomposites. To this aim, the influence of incorporation of graphene nanosheets into ultra-high molecular weight polyethylene (UHMWPE) on the thermal behavior and degradation kinetics of UHMWPE/graphene nanocomposites was investigated. Scanning electron microscopy (SEM) analysis revealed that graphene nanosheets were uniformly spread throughout the UHMWPE’s molecular chains. X-Ray Diffraction (XRD) data posited that the morphology of dispersed graphene sheets in UHMWPE was exfoliated. Non-isothermal differential scanning calorimetry (DSC) studies identified a more pronounced increase in melting temperatures and latent heat of fusions in nanocomposites compared to UHMWPE at lower concentrations of graphene. Thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG) revealed that UHMWPE’s thermal stability has been improved via incorporating graphene nanosheets. Further, degradation kinetics of neat polymer and nanocomposites have been modeled using equations such as Friedman, Ozawa–Flynn–Wall (OFW), Kissinger, and Augis and Bennett’s. The "Model-Fitting Method” showed that the auto-catalytic nth-order mechanism provided a highly consistent and appropriate fit to describe the degradation mechanism of UHMWPE and its graphene nanocomposites. In addition, the calculated activation energy (Ea) of thermal degradation was enhanced by an increase in graphene concentration up to 2.1 wt.%, followed by a decrease in higher graphene content.

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