Thermal behaviour of some ester derivatives of p-tert-butyl calix[n]arene

Saponar, Alina; Popovici, Elisabeth-Jeanne; Perhaița, I.; Nemeş, Gabriela; Cadiş, A.I.

doi:10.1007/s10973-012-2415-2

Cited by 23 publications

(8 citation statements)

References 19 publications

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“…polyurethane matrices [37]. Moreover, in the case of TS-MPUE sample, lower thermal stability compared to TC-MPUE sample may be justified by repulsion forces between sulfonates groups of TSTC4AS macrocycle on the surface of nanoparticles imbedded into polyurethane chains.…”

Section: Thermogravimetric Propertiesmentioning

confidence: 99%

Biocompatible polyurethane/thiacalix[4]arenes functionalized Fe3O4 magnetic nanocomposites: Synthesis and properties

Mohammadi

Barikani

Lakouraj

2016

Materials Science and Engineering: C

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In this study, a series of magnetic polyurethane/Fe3O4 elastomer nanocomposites were prepared by covalently embedding novel thiacalix[4]arenes (TC4As) functionalized Fe3O4 nanoparticles (TC4As-Fe3O4) which contain macrocycles with reactive hydroxyl groups. Surface functionalization of Fe3O4 nanoparticles with TC4As macrocycles as unique reactive surface modifier not only gives specific characteristics to Fe3O4 nanoparticles but also improves the interphase interaction between nanoparticles and the polyurethane matrices through covalent attachment of polymer chains to nanoparticle surfaces. The novel synthesized TC4As-Fe3O4 nanoparticles were characterized by FTIR, XRD, TGA, VSM and SEM analysis. Furthermore, the effect of functionalization of Fe3O4 nanoparticles on the various properties of resulting nanocomposites was studied by XRD, TGA, DMTA, SEM, and a universal tensile tester. It was found that the functionalization of nanoparticles with TC4As affords better mechanical and thermal properties to polyurethane nanocomposites in comparison with unmodified nanoparticles. The SEM analysis showed finer dispersion of TC4As-Fe3O4 nanoparticles than unmodified Fe3O4 nanoparticles within the polyurethane matrices, which arising from formation of covalent bonding between TC4As functionalized Fe3O4 nanoparticles and polyurethane matrices. Moreover, the investigation of in vitro biocompatibility of novel nanocomposites showed that these samples are excellent candidate for biomedical use.

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Section: Thermogravimetric Propertiesmentioning

confidence: 99%

Biocompatible polyurethane/thiacalix[4]arenes functionalized Fe3O4 magnetic nanocomposites: Synthesis and properties

Mohammadi

Barikani

Lakouraj

2016

Materials Science and Engineering: C

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“…The two main decomposition stages are accompanied by a major gas release. The FTIR characteristic absorbance bands of the gaseous products-H 2 O, CO 2 , and CO can be observed: [39,40]. In the temperature range 398-473 K (FTIR spectrum at minute [13][14], the released gases consist of H 2 O-physically adsorbed water-and CO 2 , adsorbed from the atmosphere.…”

Section: Thermal Analysismentioning

confidence: 99%

A valence states approach for luminescence enhancement by low dopant concentration in Eu-doped ZnO nanoparticles

et al. 2015

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The paper presents a simple, reproducible, controllable, and direct wet chemical synthesis method for Zn 1-x Eu x O nanoparticles. The full understanding of decomposition mechanism of the as-obtained oxalate precipitate was achieved based on the thermal analysis correlated with the evolved gas analysis and FTIR spectroscopy. The structure, morphology, and optical luminescent properties of the Zn 1-x Eu x O nanoparticles have been investigated by X-ray diffraction, Raman spectroscopy, HRTEM, SAED, XPS, and PL. The XRD studies reveal the formation of a hexagonal wurtzite-type structure. The presence of Eu 2 O 3 cubic structure can be observed up to 0.5 mol% Eu, suggesting that the solubility of the divalent or trivalent Eu into the ZnO lattice is limited. The formation of Eu 2 O 3 secondary phase at higher Eu concentration is sustained by Raman spectroscopy and XPS, as well. The TEM investigations of the Eu-doped ZnO samples illustrate the presence of aggregates with different shapes and dimensions formed by agglomerated spherical and polyhedral nanoparticles with sizes ranging from 20 to 120 nm. The effect of europium concentration on the structural and morphological characteristics, as well as on the luminescent properties was studied with special emphasis on the europium chemical states-Eu 2? and Eu 3? . The PL measurements sustain the presence of both divalent and trivalent europium ions into the ZnO host lattice and, at the same time, an increase of its defects density induced by the dopant presence.

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“…It is quite clear from the TGA results that the TC4A‐based PUEs have higher T onset , T 10% and T 50% than the PUE sample and are more thermally stable than the PUE sample extended with glycerol only. This increase in T onset , T 10% and T 50% for CPUE1, CPUE2 and CPUE3 compared to PUE is attributed to the high thermal stability of TC4A due to its four aromatic rings which delays polyurethane degradation under a nitrogen atmosphere …”

Section: Resultsmentioning

confidence: 98%

Synthesis and investigation of properties of thiacalix[4]arene-based polyurethane elastomers

2014

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A series of polyurethane elastomers (PUEs) derived from three thiacalix[4]arene derivatives (TC4As), namely p-tert-butylthiacalix[4]arene, tetrasodium thiacalix[4]arenetetrasulfonate and thiacalix[4]arenetetrasulfonic acid, as a portion of chain extender in a mixture with glycerol were synthesized. The effects of the chemical structure of TC4As used as chain extenders on the various properties of the prepared PUEs were investigated and compared with PUE extended with only glycerol as chain extender using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy and a universal tensile tester. Moreover, the effect of the introduction of TC4As as a portion of chain extender on the hydrophobicity of the PUEs was also evaluated. DSC, FTIR spectroscopy and XRD revealed that the degree of phase separation and crystallinity in TC4A-based PUEs was much higher than that of the glycerol-based ones. Thus, it was concluded that the presence of TC4As in TC4A-based PUEs seems to favour the formation of a more ordered structure due to an increase in the degree of phase separation. The TGA results also showed that, with incorporation of TC4As into the polyurethane backbone, the thermal stability of PUEs was improved.

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Thermal behaviour of some ester derivatives of p-tert-butyl calix[n]arene

Cited by 23 publications

References 19 publications

Biocompatible polyurethane/thiacalix[4]arenes functionalized Fe3O4 magnetic nanocomposites: Synthesis and properties

Biocompatible polyurethane/thiacalix[4]arenes functionalized Fe3O4 magnetic nanocomposites: Synthesis and properties

A valence states approach for luminescence enhancement by low dopant concentration in Eu-doped ZnO nanoparticles

Synthesis and investigation of properties of thiacalix[4]arene-based polyurethane elastomers

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