Synthesis, thermal analysis, and spectroscopic and structural characterizations of zinc(II) complexes with salicylaldehydes

Zianna, Ariadni; Vecchio, Stefano; Gdaniec, Мaria; Czapik, Agnieszka; Hatzidimitriou, A.; Lalia‐Kantouri, Maria

doi:10.1007/s10973-012-2719-2

Cited by 39 publications

(13 citation statements)

References 17 publications

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“…In Equation (1), Φ is the heating rate, T m is the temperature at maximum rate of weight loss, n is the apparent reaction order, R is the universal gas constant, A is the pre-exponential factor, and W m is the weight of the sample at the maximum rate of mass loss. The Kissinger equation yields reliable E a values only when conversion does not practically vary the heating rate, and it should not be considered an isoconversional method [ 45 , 46 , 47 ]. Thus, to obtain a reliable estimation of the kinetics of degradation of the prepared compounds, we checked that the degree of conversion did not vary with heating rate.…”

Section: Resultsmentioning

confidence: 99%

Kinetic Study of the Thermal and Thermo-Oxidative Degradations of Polystyrene Reinforced with Multiple-Cages POSS

et al. 2020

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A comprehensive kinetics degradation study is carried out on novel multiple cages polyhedral oligomeric silsesquioxane (POSS)/polystyrene (PS) composites at 5% (w/w) of POSS to assess their thermal behavior with respect to the control PS and other similar POSS/PS systems studied in the past. The composites are synthesized by in situ polymerization of styrene in the presence of POSSs and characterized by 1H-NMR. The characteristics of thermal parameters are determined using kinetics literature methods, such as those developed by Kissinger and Flynn, Wall, and Ozawa (FWO), and discussed and compared with each other and with those obtained in the past for similar POSS/PS composites. A good improvement in the thermal stability with respect to neat polymer is found, but not with respect to those obtained in the past for polystyrene reinforced with single- or double-POSS cages. This behavior is attributed to the greater steric hindrance of the three-cages POSS compared with those of single- or double-cage POSS molecules.

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Section: Resultsmentioning

confidence: 99%

Kinetic Study of the Thermal and Thermo-Oxidative Degradations of Polystyrene Reinforced with Multiple-Cages POSS

et al. 2020

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“…where Φ is the heating rate, T m is the temperature at maximum rate of weight loss, n is the apparent reaction order, R is the universal gas constant, A is the pre-exponential factor, and W m is the weight of sample at the maximum rate of mass loss. After ascertaining that conversion does not vary with heating, in order to ensure a reliable estimation, 18,19 E a values were calculated trough the obtained linear dependences of ln ( Φ / T m 2 ) on 1/ T m at various heating rates for both PS and nanocomposites. Degradation E a values with their corresponding regression coefficients are reported in Tables 4 and 5 for nitrogen and air, respectively.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, thermal behavior, and kinetics of degradation of alkyl hepta cyclopentyl polyhedral oligomeric silsesquioxanes/polysterene nanocomposites

Blanco

Bottino

2017

Journal of Thermoplastic Composite Materials

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The degradation of polyhedral oligomeric silsesquioxane (POSS)/polystyrene (PS) nanocomposites at different percentages of reinforcement was studied in order to verify their thermal stability in respect to the pristine PS. Analyzed compounds were prepared by in situ polymerization of styrene, in the presence of POSSs and characterized by 1H-NMR. The temperature at 5% mass loss and the activation energy of degradation, determined through kinetics literature methods, were taken into consideration in order to assess both the resistance and the kinetics of degradation. The results obtained for the synthesized polymer and composites were discussed and compared with each other and with those obtained in the past for similar alkyl-POSS/PS nanocomposites. A good improvement of the thermal stability, in respect to neat polymer, was found and showed that the presence of cyclopentyl groups at the vertices of the POSS cage led to a good interaction with the matrix. It was also drawn up a thermal stability classification among the synthesized materials and those studied in the past according to the organic nature of the substituents on the inorganic cage of the composite reinforcement.

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“…Many authors have used the thermal and nonthermal techniques in the physicochemical characterization of herbal products [35], as well as of other synthetic substances with biological activity potential [28][29][30][31][32]. All those studies showed the relevance of the thermal analysis in the determinations of the thermal parameters and stabilities of those products.…”

Section: Resultsmentioning

confidence: 99%

“…The evaluation of the stability of biologically active compounds in solid dosage form is carried out specifically by analyzing its decompositional behavior in isothermal and nonisothermal conditions [27]. Some studies that evaluate thermal behaviors of the newly synthesized biologically active compounds are reported [28][29][30][31][32].…”

Section: Introductionmentioning

confidence: 99%

Thermal characterization of some guanylhydrazones by thermal and nonthermal techniques

galvão

Brito

Dantas

et al. 2014

J Therm Anal Calorim

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2-[(3,5-di-tert-butyl-4-hydroxyphenyl)methylene]-hydrazinecarboximidamide (WE010), 2-([1,1 0 -biphenyl]-4-ylmethylene)-hydrazinecarboximidamide (WE014), and 2-[(3,4-dichlorophenyl)methylene]-hydrazinecarboximidamide (WE017) are guanylhydrazone derivatives widely studied biologically and chemically; however, there are no studies regarding their thermal behaviors. The present study aims to apply the thermal analyses: differential scanning calorimetry (DSC), differential scanning calorimetry coupled to the photovisual system (DSC-photovisual), and thermogravimetry (TG), to characterize the guanylhydrazones, as well as HPLC and FTIR. The DSC curve of WE010 shows a melting process with T onset at 190°C and peak at 193.5°C (DH 41.0 J g -1 ). Due to the symmetry of the melting peaks obtained by DSC, it is possible to calculate the purity of the sample (98.87 %). The DSC curve of WE014 shows the melting process in the range of 208-213°C, with a melting peak at 211°C (DH 61 J g -1 ).The DSC curve of WE017 showed T onset at 215°C and peak temperature of 219°C (DH 55 J g -1 ). The TG curve of WE010, WE014, and WE017 presents initial decomposition temperatures of 186.95, 197.31, and 195.44°C, respectively. The DSC-photovisual confirmed the results of DSC and TG. The HPLC determined the purities of the samples and confirmed the results of DSC. The FTIR confirmed the thermal data. Thus, the use of thermal analysis is an important tool for the characterization of molecules with therapeutic potential contributing to the characterization and evaluation of their stability as well as nonthermal technique with complementary tool.

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Synthesis, thermal analysis, and spectroscopic and structural characterizations of zinc(II) complexes with salicylaldehydes

Cited by 39 publications

References 17 publications

Kinetic Study of the Thermal and Thermo-Oxidative Degradations of Polystyrene Reinforced with Multiple-Cages POSS

Kinetic Study of the Thermal and Thermo-Oxidative Degradations of Polystyrene Reinforced with Multiple-Cages POSS

Synthesis, thermal behavior, and kinetics of degradation of alkyl hepta cyclopentyl polyhedral oligomeric silsesquioxanes/polysterene nanocomposites

Thermal characterization of some guanylhydrazones by thermal and nonthermal techniques

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