scholarly journals Effect of Substitutions on Thermal Behavior of Symmetric Doubleschiff Bases of 1,1’-Bis(4-Amino Phenyl)Cyclohexane

2016 ◽  
Vol 63 ◽  
pp. 145-149
Author(s):  
Bhavesh J. Gangani ◽  
Parsotam H. Parsania
Keyword(s):  
Thermal Properties ◽  
Thermal Behavior ◽  
Kinetic Parameters ◽  
Schiff Bases ◽  
Frequency Factor ◽  
Entropy Change ◽  
Nitrogen Atmosphere ◽  
Energy Of Activation ◽  
Thermo Gravimetric ◽  
Degradation Kinetic

Thermo gravimetric analyses of some symmetric double Schiff bases of 1, 1’- bis (4-amino phenyl) cyclohexane (SDSB-1 to SDSB-6) was carried out at 100C/min in nitrogen atmosphere. Schiff bases are thermally stable up to 200-285°C and followed two step degradation kinetic. Various kinetic parameters such as order of degradation (n), energy of activation (Ea), frequency factor (A) and entropy change (ΔS) were derived accordingly Anderson-Freeman method interpreted in light of nature of the substituents. The nature, size and position of substituents affected thermal properties of the Schiff bases.

scholarly journals Thermal Analysis of some Imidazolinone Derivatives

2015 ◽  
Vol 44 ◽  
pp. 124-129
Author(s):  
Shipra Baluja ◽  
Nikunj Kachhadia
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Kinetic Parameters ◽  
Frequency Factor ◽  
Entropy Change ◽  
Energy Of Activation ◽  
Thermal Stability Of

Thermal analysis of some imidazolinone derivatives derived from 1, N-phenyl-3-p-nitrophenyl-4-formyl pyrazole, have been carried out by TGA technique. From these thermograms, various kinetic parameters such as order of degradation (n), energy of activation (E), frequency factor (A) and entropy change (∆S) have been evaluated. Further, thermal stability of imidazolinone derivatives have been determined, which is found to depend on the type of substituent present in the compounds.

scholarly journals Thermal Study of Anhydrides Cured Tetrafunctional Cardo Epoxy Resin

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jignesh P. Patel ◽  
Parsotam H. Parsania
Keyword(s):  
Thermal Properties ◽  
Maleic Anhydride ◽  
Epoxy Resin ◽  
Degradation Kinetics ◽  
Frequency Factor ◽  
Entropy Change ◽  
Thermal Study ◽  
Gel Time ◽  
Degradation Reactions ◽  
Different Types

Tetrafunctional cardo epoxy resin (EBCF) was cured by using 10 wt% maleic anhydride (MA), pyromellitic dianhydride (PMDA), phthalic anhydride (PA), tetrahydrophthalic anhydride (THPA), tetrabromophthalic anhydride (TBPA), and tetrachlorophthalic anhydride (TCPA) as hardeners at 120°C for 40–105 min (gel time) and then postcured 1 h at 130°C. Gel time is found to depend on the structure of the anhydrides used. Cured samples were found insoluble in common solvents. Cured and uncured EBCF were characterized by FTIR, DSC, and TGA techniques. Cured and uncured resins followed multistep degradation reactions. Kinetic parameters, namely, order of degradation, energy of activation, frequency factor, and entropy change, were determined according to the Anderson-Freeman method and interpreted in light of the nature of hardeners used for curing purpose. The resins followed integral or fractional order degradation kinetics. Complex degradation reactions are due to different types of linkages in cured resins. Both nature and structure of resin and hardeners affected the curing behavior and the resultant thermal properties of the cured resins.

scholarly journals Study of Non-Isothermal Decomposition and Kinetic Analysis of 2,4-Dihydroxybenzoic Acid- Melamine-Formaldehyde Copolymer

2010 ◽  
Vol 7 (3) ◽  
pp. 1101-1107 ◽  
Author(s):  
S. S. Butoliya ◽  
W. B. Gurnule ◽  
A. B. Zade
Keyword(s):  
Kinetic Parameters ◽  
Average Molecular Weight ◽  
Acid Catalyst ◽  
Conductometric Titration ◽  
Frequency Factor ◽  
Entropy Change ◽  
Dihydroxybenzoic Acid ◽  
H Nmr ◽  
Uv Visible

A copolymer (2,4-DHBAMF) synthesized by the condensation of 2,4-dihydroxybenzoic acid and melamine with formaldehyde in the presence of acid catalyst using varied molar proportions of the reactants. A composition of the copolymer has been determined by elemental analysis. The number average molecular weight has been determined by conductometric titration in non-aqueous medium. The copolymer has been characterized by UV-Visible, IR and1H NMR spectral analysis. Thermogravimetric analysis was carried out to study the decomposition and various kinetic parameters. Freeman Carroll and Sharp Wentworth methods have been applied for the calculation of kinetic parameters while the data from Freeman Carroll method have been used to determine various thermodynamic parameters such as order of reaction, energy of activation, frequency factor, entropy change, free energy change and apparent entropy change. The results indicate that given copolymer have potential as matrix resin for long term applications at temperature up to 350°C.

Thermal behavior and thermal degradation kinetic parameters of triterpene α, β amyrin

2017 ◽  
Vol 127 (2) ◽  
pp. 1757-1766 ◽  
Author(s):  
Walter Ferreira da Silva Júnior ◽  
Jonas Gabriel de Oliveira Pinheiro ◽  
Carlos Demócedes Luís de França Alm Moreira ◽  
André Luis Rüdiger ◽  
Euzébio Guimarães Barbosa ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Thermal Behavior ◽  
Kinetic Parameters ◽  
Degradation Kinetic ◽  
Thermal Degradation Kinetic

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.

scholarly journals Determination of Kinetic Parameters of Decomposition of Tetrahydropyrimidine Derivatives

2013 ◽  
Vol 18 ◽  
pp. 23-32
Author(s):  
Kapil Bhesaniya ◽  
Ashish Patel ◽  
Shipra Baluja
Keyword(s):  
Thermal Analysis ◽  
Kinetic Parameters ◽  
Frequency Factor ◽  
Entropy Change ◽  
Structural Determination ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
Tga And Dsc ◽  
Thermal Stability Of

Some new tetrahydropyrimidine derivatives have been synthesized and their structural determination was done by IR, NMR and mass spectral data. Thermal analysis of these synthesized dihydropyrimidinthiones has been carried out by TGA and DSC techniques. From the thermograms, various kinetic parameters such as order of degradation (n), energy of activation (E), frequency factor (A) and entropy change (ΔS) have been evaluated. Further, thermal stability of tetrahydropyrimidine have been determined which is found to depend on the type of substituent present in the compounds.

scholarly journals The evaluation of kinetic parameters for cadmium doped Co-Zn ferrite using thermogravimetric analysis

2019 ◽  
Vol 30 (1) ◽  
pp. 60-64 ◽  
Author(s):  
Akshay B. Kulkarni ◽  
Shridhar N. Mathad ◽  
Raghavendra P. Bakale
Keyword(s):  
Kinetic Parameters ◽  
Zinc Ferrite ◽  
Frequency Factor ◽  
Entropy Change ◽  
Solid State Reaction Method ◽  
Enthalpy Change ◽  
Ferrite Sample ◽  
Zn Ferrite ◽  
Cobalt Zinc Ferrite ◽  
Evaluation Of Kinetic Parameters

AbstractThis work had the objective to analyze the thermodynamic properties of cadmium doped cobalt zinc ferrite (Co0.5Zn0.5Cd0.3Fe1.8O4), obtained by solid state reaction method and characterized by TGA-DTA. The TG analysis show sharp peaks at four points, two for water reduction, one for decomposition of chlorides and last one for formation of end product. The ratio of weight of end product to starting material match with ratio of molecular weight of end product and starting materials; this confirms the formation of ferrite sample. Broido, Coats-Redfern, Chang and Horowitz-Metzger approximations are employed to compute the activation energy (Ea) of formation of ferrite sample. The kinetic parameters like frequency factor (A), entropy change (ΔS), enthalpy change (ΔH) and changes in internal energy (ΔG) of sample are also reported.

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.

Thermogravimetric Investigation of Calcium Oxalate

2013 ◽  
Vol 850-851 ◽  
pp. 160-163
Author(s):  
Jun Song ◽  
Jian Wang ◽  
Li Wang
Keyword(s):  
Thermal Properties ◽  
Calcium Oxalate ◽  
Heating Rate ◽  
Reaction Temperature ◽  
Close Packing ◽  
Heat Transmission ◽  
Temperature Zone ◽  
Nitrogen Gas ◽  
Thermo Gravimetric ◽  
Thermogravimetric Investigation

The thermal properties of calcium oxalate were studied by means of TG analyzer. The factors such as heating rate, filling amounts of specimens and filling atmosphere etc., which may affect thermo gravimetric (TG) curves in TG analysis test were investigated. The results showed that, with the improving of heating rate, filling amounts of specimens and close packing, the starting reaction temperature was postponed more obviously and the width of reaction temperature range rises. The flow of the nitrogen gas enhanced heat transmission, caused the starting reaction temperature to shift to the low temperature zone, and it could also affect the response course. But the factors above didnt obviously influence the weightlessness of specimens.

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