scholarly journals Kinetic Modeling and Degradation Study of Liquid Polysulfide Resin-Clay Nanocomposite

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 635
Author(s):  
Mohamadreza Shakiba ◽  
Arash Kakoei ◽  
Iman Jafari ◽  
Erfan Rezvani Ghomi ◽  
Mohammadreza Kalaee ◽  
...  
Keyword(s):  
Experimental Data ◽  
Kinetic Modeling ◽  
Degradation Kinetics ◽  
Nitrogen Atmosphere ◽  
Gravimetric Analysis ◽  
Degradation Kinetic ◽  
Kinetic Evaluation ◽  
Degradation Study ◽  
Clay Nanoparticles ◽  
Conversion Rates

Kinetic modeling and degradation study of liquid polysulfide (LPS)/clay nanocomposite is possible through Ozawa–Flynn–Wall (OFW) and Kissinger methods. Comparing the results of these models with experimental data leads to provide an accurate degradation kinetic evaluation of these materials. To this aim, the morphology and distribution of clay nanoparticles (CNPs) within the LPS matrix were investigated using Field Emission Scanning Electron Microscopy (FESEM) and X-ray diffraction (XRD). To evaluate the interaction between the LPS and the CNPs, the Fourier transform infrared (FTIR) identification was utilized. Furthermore, to investigate the kinetics of degradation, the thermal gravimetric analysis (TGA) and derivative thermogravimetry (DTG) of the samples were used in the nitrogen atmosphere with the help of Kissinger and Ozawa–Flynn–Wall (OFW) models. The characterization results confirmed the homogenous dispersion of the CNPs into the LPS matrix. In addition, the presence of CNPs increased the thermal stability and activation energy (Ea) of the samples at different conversion rates. Moreover, the OFW method was highly consistent with the experimental data and provided an appropriate fit for the degradation kinetics.

Thermal degradation kinetics of PP/PLA nanocomposite blends

2018 ◽  
Vol 32 (12) ◽  
pp. 1714-1730 ◽  
Author(s):  
Dev K Mandal ◽  
Haripada Bhunia ◽  
Pramod K Bajpai
Keyword(s):  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Frequency Factor ◽  
Nitrogen Atmosphere ◽  
Thermal Degradation Kinetics ◽  
Heating Rates ◽  
Degradation Kinetic ◽  
Thermal Degradation Behavior ◽  
Kinetics Of ◽  
Thermal Stability Of

In this article, the effect of adding polylactide (PLA) and nanoclay on the thermal stability of polypropylene (PP) films was analyzed using thermogravimetric analysis. The thermal degradation kinetic parameters such as activation energy ( Ea), order of reaction ( n), and frequency factor (ln ( Z)) of the samples were studied over a temperature range of 30–550°C. Analyses were performed under nitrogen atmosphere with four different heating rates (i.e. 5, 10, 15, and 20°C min−1). The Ea was calculated by Kissinger, Kim–Park, and Flynn–Wall methods. The Ea value of PP was much higher than PLA, whereas the addition of PLA and nanoclay in PP decreased the Ea. The addition of compatibilizer increased the compatibility and Ea of blended films upto some extent. The lifetime of PP was found to be decreased with the addition of PLA and nanoclay. Studies indicated that the thermal degradation behavior and lifetime of the investigated samples depend on the fractions of constituents and heating rates.

Thermal Stabilities and the Thermal Degradation Kinetics Study of the Flame Retardant Epoxy Resins

2014 ◽  
Vol 1053 ◽  
pp. 263-267 ◽  
Author(s):  
Xiu Juan Tian
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Degradation Kinetics ◽  
Thermal Degradation Kinetics ◽  
Thermal Stabilities ◽  
Degradation Kinetic ◽  
Modified Epoxy

Thermal stability and thermal degradation kinetics of epoxy resins with 2-(Diphenylphosphinyl)-1, 4-benzenediol were investegated by thermogravimetric analysis (TGA) at different heating rates of 5 K/min, 10 K/min, 20 K/min and 40 K/min. The thermal degradation kinetic mechanism and models of the modified epoxy resins were determined by Coast Redfern method.The results showed that epoxy resins modified with the flame retardant had more thermal stability than pure epoxy resin. The solid-state decomposition mechanism of epoxy resin and the modified epoxy resin corresponded to the controlled decelerating ځ˽̈́˰̵̳͂͆ͅ˼˰̴̱̾˰̸̵̈́˰̵̸̳̱̹̽̾̓̽˰̶̳̹̾̈́̿̾̓ͅ˰̶˸ځ˹˰̵̵͇͂˰̃˸́˽ځ˹2/3. The introduction of phosphorus-containing flame retardant reduced thermal degradation rate of epoxy resins in the primary stage, and promote the formation of carbon layer.

Non-isothermal degradation kinetics for polycarbonate/ polymethylphenylsilsesquioxane composites

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Jiangbo Wang ◽  
Zhong Xin
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Flame Retardancy ◽  
Degradation Kinetics ◽  
Degradation Process ◽  
Nitrogen Atmosphere ◽  
Ozawa Method ◽  
Degradation Behaviors ◽  
Thermal Degradation Process

AbstractThe thermal degradation behaviors of PC/PMPSQ (polymethylphenylsilsesquioxane) systems were investigated by thermogravimetric analysis (TGA) under non-isothermal conditions in nitrogen atmosphere. During non-isothermal degradation, Kissinger and Flynn-Wall-Ozawa methods were used to analyze the thermal degradation process. The results showed that a remarkable decrease in activation energy ( E ) was observed in the early and middle stages of thermal degradation in the presence of PMPSQ, which indicated that the addition of PMPSQ promoted the thermal degradation of PC. Flynn-Wall-Ozawa method further revealed that PMPSQ significantly increased the activation energy of PC thermal degradation in the final stage, which illustrated that the PMPSQ stabilized the char residues and improved the flame retardancy of PC in the final period of thermal degradation process

Thermo-oxidative and thermal degradation kinetics of silica/polymethyl methacrylate composites with electrostatic interaction phase interfaces

2019 ◽  
Vol 39 (2) ◽  
pp. 105-116 ◽  
Author(s):  
Hongyan Li ◽  
Yongqiang Fu ◽  
Hongli Liu ◽  
Cong Sun ◽  
Ruyi Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Polymethyl Methacrylate ◽  
Electrostatic Interaction ◽  
Degradation Kinetics ◽  
Thermal Degradation Kinetics ◽  
Degradation Kinetic ◽  
Further Development ◽  
Kinetics Of ◽  
Insulation Performance

AbstractThe thermo-oxidative and thermal degradation kinetic parameters of polymethyl methacrylate-methacryloxyethyltrimethyl ammonium chloride/silica aerogel composites (PMMA-MTC/SA) were investigated in this paper and were compared with the thermal stability and thermal conductivity of different types of composites. As a composite with electrostatic interaction, the thermo-oxidative and thermal degradation activation energies (E) of PMMA-MTC/SA were 173.97 and 188.05 kJ/mol, respectively. The results indicated that the electrostatic interaction could indeed enhance the thermal stability of silica/polymethyl methacrylate composites on the premise of good mechanical properties and heat insulation performance. It is of great significance for the further development of silica-based thermal insulation composites.

scholarly journals Using Kinetic Modeling and Experimental Data to Evaluate Mechanisms in PET‐RAFT

2020 ◽  
Vol 58 (1) ◽  
pp. 139-144 ◽  
Author(s):  
Leah R. Kuhn ◽  
Michael L. Allegrezza ◽  
Nicholas J. Dougher ◽  
Dominik Konkolewicz
Keyword(s):  
Experimental Data ◽  
Kinetic Modeling

scholarly journals Photocatalytic degradation as Davidson–Cole relaxation in time domain

2019 ◽  
Vol 09 (01) ◽  
pp. 1950006 ◽  
Author(s):  
C. L. WANG
Keyword(s):  
Experimental Data ◽  
Differential Equations ◽  
Photocatalytic Degradation ◽  
Gamma Function ◽  
Time Domain ◽  
Degradation Kinetics ◽  
Incomplete Gamma Function ◽  
Response Functions ◽  
Degradation Processes

Photocatalytic degradation processes of different materials are fitted with Mittag-Leffler function and incomplete gamma function, which are response functions for Cole–Cole relaxation and Davidson–Cole relaxation. The fitting results show that both functions can fit experimental data fairly well. The order of derivative in the kinetic differential equations can be either less, or greater than one. In the case of the order of derivative is greater than one, only incomplete gamma function is reasonable for describing the photocatalytic degradation. This work further confirms the existence of the universality in photocatalytic degradation kinetics.

Kinetic modeling and mechanistic investigations of transesterification of propylene carbonate with methanol over an Fe–Mn double metal cyanide catalyst

2020 ◽  
Vol 5 (1) ◽  
pp. 101-111
Author(s):  
Ziwei Song ◽  
Bala Subramaniam ◽  
Raghunath V. Chaudhari
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Propylene Carbonate ◽  
Kinetic Modeling ◽  
Reaction Parameters ◽  
Metal Cyanide ◽  
Wide Range ◽  
Mechanistic Investigations ◽  
Activation Sequence

A kinetic model involving the activation sequence of reactants PC, methanol and an intermediate provides the best description of the experimental data with respect to reaction parameters over a wide range of conditions.

Evaluation of mathematical models to describe protein fraction degradation kinetics of various oilseed meals

2009 ◽  
Vol 2009 ◽  
pp. 171-171
Author(s):  
M Danesh Mesgaran ◽  
T Tashakkori ◽  
A Heravi Moussavi ◽  
S Danesh Mesgaran ◽  
A Vakili ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Goodness Of Fit ◽  
Degradation Kinetics ◽  
Direct Method ◽  
Rapeseed Meal ◽  
Insoluble Protein ◽  
Degradation Kinetic ◽  
Negative Exponential ◽  
Kinetics Of

In situ procedure is a direct method of measuring the rumen degradation kinetic of a feed nutrient. Data obtained by this technique are generally analysed using an exponential curve (Ørskov and McDonald, 1979). However, very low attention has been paid to choice of mathematical model to fit the curves and goodness-of-fit of the model. Lopez et al. (1999) pointed out that the disappearance of some feed components, particularly structural carbohydrates, exhibits a larger variety of forms than for crude protein (CP). In the present study, two different mathematical models of a straight line or a negative exponential (France et al., 1990; and Ørskov and McDonald, 1979) were selected to evaluate in situ degradation kinetics of protein fractions including true protein (TP), neutral-detergent insoluble protein (NDIP) and acid-detergent insoluble protein (ADIP) of various oilseed meals (cottonseed meal (CSM), soyabean meal (SM) and rapeseed meal (RM)).

Pyrolysis kinetics of recycled polyesters

2015 ◽  
Vol 27 (4) ◽  
pp. 523-531 ◽  
Author(s):  
Jaber Al-Juaidiyah
Keyword(s):  
Textile Industry ◽  
Degradation Kinetics ◽  
Nitrogen Atmosphere ◽  
Coefficient Of Determination ◽  
Pyrolysis Kinetics ◽  
Polybutylene Terephthalate ◽  
Exponential Factor ◽  
Content Type ◽  
Kissinger Model ◽  
Kinetics Of

Purpose – The purpose of this paper is to study the non-isothermal degradation kinetics of recycled polybutylene terephthalate, polytrimethylene terephthalate and polyethylene terephthalate using thermogravimetric analysis (TGA) in a nitrogen atmosphere. Design/methodology/approach – To achieve this goal, the author utilized standard kinetic models, such as Coats-Redfern and Kissinger equations, for analysis of the TGA data. Findings – When applied to the TGA data, the Kissinger model resulted in a coefficient of determination (R2) value greater than 0.99. Originality/value – This study describes the maiden application of the Kissinger model to obtain the pre-exponential factor (A) and activation energy (E) for different polyester systems used in the textile industry.

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