Synthesis and characterization of a novel isocoumarin derived polymer and its thermal decomposition kinetics

Kurt, Adnan; Avci, H.I.; Koca, Murat

doi:10.20450/mjcce.2018.1503

Cited by 7 publications

(13 citation statements)

References 27 publications

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“…The linearity for this line was found to be R 2 = 0.994. The activation energies of both the Kissinger and Flynn-Wall-Ozawa methods are very similar, with only a 7.3 kJ/mol difference between them, thereby illustrating the reliability of the results [16,17,29]. The thermal degradation mechanism of the bithiazole-containing conjugated polymer was determined when the activation energies calculated from the various kinetic methods in the literature were compared with the activation energies obtained from the Flynn-Wall-Ozawa and Kissinger methods.…”

Section: Resultsmentioning

confidence: 74%

“…The closest value to the calculated average activation energy value was obtained with the value corresponding to 288.5 kJ/mol at the conversion of 11 %. An increase in the activation energy values was also observed depending on the increase in the percentages of decomposition [16][17][18]29]. In order to evaluate the thermal degradation kinetics of the bithiazole-containing conjugated polymer, the Kissinger method, another kinetic method independent of reaction order, was used to support and confirm the thermal degradation activation energies calculated from the Flynn-Wall-Ozawa method.…”

Section: Resultsmentioning

confidence: 99%

“…The present study reports the synthesis, characterization and investigation of the thermal degradation kinetics [9][10][11][12][13][14][15] of a new conjugated polymer containing a heterocyclic group, such as the bithiazole group. The degradation kinetics are investigated using thermogravimetric/derivative thermogravimetric (TG/DTG) techniques [16][17][18][19][20]. The kinetics of the pyrolysis process of the newly generated polymer give the best description of the studied pyrolysis process and allow for the determination of reliable values for the kinetic parameter.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and characterization of a new conjugated polymer containing bithiazole group and its thermal decomposition kinetics

Kurt

Andan

Koca

2020

Maced. J. Chem. Chem. Eng.

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A new conjugated polymer containing a bithiazole group is prepared by the polycondensation of 2,2'-diamino-4,4'-bithiazole and terephthaldialdehyde in the presence of glacial acetic acid. The kinetics of thermal degradation of the new polymer are investigated by thermogravimetric analysis at different heating rates. The temperature corresponding to the maximum rate loss shifts to higher temperatures with increasing heating rate. The thermal decomposition activation energies of the conjugated polymer in a conversion range of 3–15 % are 288.4 and 281.1 kJ/mol by the Flynn–Wall–Ozawa and Kissinger methods, respectively. The Horowitz–Metzger method shows that the thermodegradation mechanism of the conjugated polymer proceeds over a three-dimensional diffusion type deceleration D3 mechanism. The optimum heating rate is 20 ºC/min.

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Section: Resultsmentioning

confidence: 74%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Synthesis and characterization of a new conjugated polymer containing bithiazole group and its thermal decomposition kinetics

Kurt

Andan

Koca

2020

Maced. J. Chem. Chem. Eng.

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“…Similar results for thermal degradation of heterocyclic polymers have been reported in our previous publications and also by different researchers. [34][35][36][37][38][39][40][41][42] For example, Kurt et al 37 reported the degradation temperatures of an isocoumarin derived polymer changed in a positive direction, which increased 256.6 °C to 286.1 °C by increasing heating rate from 5 to 20 °C/min. Meng and friends investigated the thermal degradation kinetics of a polyimide polymer containing 2,6-benzobisoxwwwwazole units and reported the onset decomposition temperatures increased with increase of heating rates.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, Characterization and Thermal Degradation Kinetics of a New Pyrazole Derived Methacrylate Polymer, Poly(1,3-Diphenyl-1H-Pyrazol-5-Yl Methacrylate)

Kurt

Koca²

2022

ACSi

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Since the behavior and properties of macromolecular pyrazole derived polymers differ from their small molecules, such polymers are in the class of well-defined functional polymers due to the fact that the pyrazole ring contains two π-bonds as well as two hetero atoms in its structure, and this feature makes them important in the fields of scientific and technological applications. In present study, therefore, we synthesized a new pyrazole derived methacrylate monomer, 1,3-diphenyl-1H-pyrazol-5-yl methacrylate, from the reaction of 1,3-diphenyl-5-pyrazolone with methacryloyl chloride in the presence of triethylamine. After that, its homopolymerization was carried out by free radical polymerization method at 60 °C initiated with benzoyl peroxide. Spectral characterizations were achieved by 1H-NMR and FTIR spectroscopies. The kinetics of thermal degradation of the new polymer, poly(1,3-diphenyl-1H-pyrazol-5-yl methacrylate), poly(DPPMA), were investigated by thermogravimetric analysis (TGA) at different heating rates. The initial decomposition temperature of the polymer changed from 216.3 °C to 243.5 °C depending on the increasing heating rate. The thermal decomposition activation energies in a conversion range of 7–19% were 79.45 kJ/mol and 81.56 kJ/mol by the Flynn– Wall–Ozawa and Kissinger methods, respectively. Thermodegradation mechanism of the poly(DPPMA) were investigated in detail by using different kinetic methods available in the literature such as Coats-Redfern, Tang, Madhusudanan and Van Krevelen. Among all these methods, the best result was obtained for Coats-Redfern method (E = 90.93 kJ/mol) at the optimum heating rate of 15 °C/min for D1 mechanism that is a one-dimensional diffusion type deceleration mechanism.

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“…The structurally diverse isocoumarin derivatives X(1–20) were synthesised according to the general synthetic route shown in Scheme 1 . 3-Acetylisocoumarin-substituted compounds B were synthesised as previously described by some of us 15 . The hydrazone derivatives X(1–5) were obtained by reacting B with substituted hydrazines 16 .…”

Section: Resultsmentioning

confidence: 99%

Isocoumarins: a new class of selective carbonic anhydrase IX and XII inhibitors

Onyılmaz

Koca

Bonardi

et al. 2022

Journal of Enzyme Inhibition and Medicinal Chemistry

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Isocoumarins, isomeric to comarins which act as effective carbonic anhydrase (CA, EC 4.2.1.1) inhibitors, were investigated for the first time as inhibitors of this enzyme. A series of 3-substituted and 3,4-disubstituted isocoumarins incorporating phenylhydrazone, 1-phenyl-pyrazole and pyrazolo-substituted pyrimidine trione/thioxo-pyrimidine dione moieties were investigated for their interaction with four human (h) CA isoforms, hCA I, II, IX and XII, known to be important drug targets. hCA I and II were not inhibited by these compounds, whereas hCA IX and XII were inhibited in the low micromolar range by the less bulky derivatives. The inhibition constants ranged between 2.7–78.9 µM against hCA IX and of 1.2–66.5 µM against hCA XII. As for the coumarins, we hypothesise that the isocoumarins are hydrolysed by the esterase activity of the enzyme with formation of 2-carboxy-phenylacetic aldehydes which act as CA inhibitors. Isocoumarins represent a new class of CA inhibitors.

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Synthesis and characterization of a novel isocoumarin derived polymer and its thermal decomposition kinetics

Cited by 7 publications

References 27 publications

Synthesis and characterization of a new conjugated polymer containing bithiazole group and its thermal decomposition kinetics

Synthesis and characterization of a new conjugated polymer containing bithiazole group and its thermal decomposition kinetics

Synthesis, Characterization and Thermal Degradation Kinetics of a New Pyrazole Derived Methacrylate Polymer, Poly(1,3-Diphenyl-1H-Pyrazol-5-Yl Methacrylate)

Isocoumarins: a new class of selective carbonic anhydrase IX and XII inhibitors

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