Studies on thermal degradation of oligo-2-[(4-morpholin-4-yl-phenyl)imino methyl] phenol and oligomer–metal complex compounds

Bi̇li̇ci̇

2009

Polymer International

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BACKGROUND: Polymers of phenols and aromatic amines have emerged as new materials in fields such as superconductors, coatings, laminates, photoresists and high‐temperature environments. The stability, kinetics and associated pollution of the thermal decomposition of oligophenols are of interest for the aforementioned fields. RESULTS: A new Schiff base polymer, derived from N,N′‐bis(2‐hydroxy‐3‐methoxyphenylmethylidene)‐2,6‐pyridinediamine, was prepared by oxidative polycondensation. Characterisations using Fourier transform infrared, UV‐visible, 1H NMR and 13C NMR spectroscopy, thermogravimetric/differential thermal analysis, gel permeation chromatography, cyclic voltammetry and conductivity measurements were performed. The number‐average (Mn) and weight‐average molecular weight (Mw) and dispersity (D = Mw/Mn) of the polymer were found to be 61 000 and 94 200 g mol−1 and 1.54, respectively. Apparent activation energies of the thermal decomposition of the polymer were determined using the Tang, Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose and Coats–Redfern methods. The most likely decomposition process was a Dn deceleration type in terms of the Coats–Redfern and master plot results. CONCLUSION: The mechanism of the degradation process can be understood through the use of kinetic parameters obtained from various non‐isothermal methods. Copyright © 2009 Society of Chemical Industry

Section: Introductionmentioning

confidence: 99%

Schiff base‐substituted polyphenol: synthesis, characterisation and non‐isothermal degradation kinetics

Kaya

Bi̇li̇ci̇

2009

Polymer International

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“…In our previous study, we reported that the thermal stabilities of N, N ′‐bis(3,5‐di‐ t ‐butylsalicylideneimine)‐1,3‐propanediamine complexes of cobalt, nickel, iron, and copper increased in the following sequence: Ni(II) > Cu(II) > Co(II) > Fe(II) 22. Then, in another study, we determined that the thermal stabilities of the metal complexes of the oligo‐2‐[(4‐morpholin‐4‐yl‐phenyl)imino]methylphenol were in the following sequence: Cu(II) > Co(II) > Zn(II) > Zr(II) > Pb(II) > Cd(II) 10. As expected, these results clearly show that the thermal stabilities of the complexes increased as the ionic radii decreased.…”

Section: Resultsmentioning

confidence: 99%

“…Copper(II)‐chelated polyazomethines were synthesized, and the influence of the copper content on the thermal behavior was studied by Oriol et al6 Thermally stable Schiff‐base polymers and their metal(II) complexes were reported by Mart 7. Schiff‐base substitute oligo/polyphenol–metal complexes and their thermal properties were examined by Kaya and coworkers 8–10…”

Section: Introductionmentioning

confidence: 99%

“…7 Schiff-base substitute oligo/polyphenol-metal complexes and their thermal properties were examined by Kaya and coworkers. [8][9][10] In this study, the thermal properties and decomposition kinetics of 2,3-bis[(2-hydroxyphenyl)methylene] diaminopyridine (HPMDAP), oligo-2,3-bis[(2-hydroxyphenyl) methylene] diaminopyridine (OHPMDAP), and oligo-2,3-bis[(2-hydroxyphenyl)methylene] diaminopyridine-metal complexes (OHPMDAP-M) of Zn(II), Pb(II), Ni(II), Cr(III), Fe(II), Cu(II), Co(II), and Cd(II) were investigated. In the decomposition kinetic study, methods such as Coats-Redfern (CR), 11 Horowitz-Metzger (HM), 12 Madhusudanan-Krishnan-Ninan (MKN), 13 van Krevelen (vK), 14 Wanjun-Yuwen-Hen-Cunxin (WYHC), 15 and MacCallum-Tanner (MT) 16 were used for the calculation of kinetic parameters such as the reaction order (n), the activation energy (E), entropy change of activation (DS # ), enthalpy change of activation (DH # ), Gibbs free energy change of activation (DG # ), and pre-exponential factor (A).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermal decomposition studies of Schiff‐base‐substitute polyphenol–metal complexes

J of Applied Polymer Sci

Kaya

2012

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The thermal behaviors of 2,3‐bis[(2‐hydroxyphenyl)methylene] diaminopyridine, oligo‐2,3‐bis[(2‐hydroxyphenyl)methylene] diaminopyridine, and some oligo‐2,3‐bis[(2‐hydroxyphenyl) methylene] diaminopyridine–metal complexes were studied in a nitrogen atmosphere with thermogravimetric analysis, derivative thermogravimetric analysis, and differential thermal analysis techniques. The decompositions of oligo‐2,3‐bis[(2‐hydroxyphenyl) methylene] diamino pyridine–metal complexes occurred in multiple steps. The values of the activation energy (E) and reaction order of the thermal decomposition were calculated by means of several methods, including Coats–Redfern, Horowitz–Metzger, Madhusudanan–Krishnan–Ninan, van Krevelen, Wanjun–Yuwen–Hen–Cunxin, and MacCallum–Tanner on the basis of a single heating rate. The most appropriate method was determined for each decomposition step according to a least‐squares linear regression. The E values obtained by each method were in good agreement with each other. It was found that the E values of the complexes for the first decomposition stage followed the order EOHPMDAP–Ni > EOHPMDAP–Cd > EOHPMDAP–Cu > EOHPMDAP–Fe > EOHPMDAP–Zn > EOHPMDAP–Co > EOHPMDAP–Cr > EHPMDAP > EOHPMDAP. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

“…It is commonly believed that a single dynamic curve is equivalent to a large number of comparable isothermal curves and the theories developed for estimating isothermal reaction rate kinetic parameters can be applied to nonisothermal data. Thermogravimetry is a powerful tool to characterize the kinetic behavior of polymers . Doğan et al has been investigated the thermal behavior of azomethine‐based phenol polymer using different kinetic methods in a nitrogen atmosphere by thermogravimetric/derivative thermogravimetric analysis (DTG) and DTA.…”

Section: Introductionmentioning

confidence: 99%

Thermal decomposition behavior of oligo(4-hydroxyquinoline)

2013

Polym Eng Sci

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In this study, the kinetic parameters and reaction mechanism of decomposition process of oligo(4‐hydroxyquinoline) synthesized by oxidative polymerization were investigated by thermogravimetric analysis (TGA) at different heating rates. TGA‐derivative thermogravimetric analysis curves showed that the thermal decomposition occurred in two stages. The methods based on multiple heating rates such as Kissinger, Kim–Park, Tang, Flynn–Wall–Ozawa method (FWO), Friedman, and Kissinger–Akahira–Sunose (KAS) were used to calculate the kinetic parameters related to each decomposition stage of oligo(4‐hydroxyquinoline). The activation energies obtained by Kissinger, Kim–Park, Tang, KAS, FWO, and Friedman methods were found to be 153.80, 153.89, 153.06, 152.62, 151.25, and 157.14 kJ mol−1 for the dehydration stage, 124.7, 124.71, 126.14, 123.75, 126.19, and 124.05 kJ mol−1 for the thermal decomposition stage, respectively, in the conversion range studied. The decomposition mechanism and pre‐exponential factor of each decomposition stage were also determined using Coats–Redfern, van Krevelen, Horowitz–Metzger methods, and master plots. The analysis of the master plots and methods based on single heating rate showed that the mechanisms of dehydration and decomposition stage of oligo(4‐hydroxyquinoline) were best described by kinetic equations of An mechanism (nucleation and growth, n = 1) and Dn mechanism (dimensional diffusion, n = 6), respectively. POLYM. ENG. SCI., 54:992–1002, 2014. © 2013 Society of Plastics Engineers