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Morphology, dynamic mechanical, thermal, and crystallization behaviors of poly(trimethylene terephthalate)/polycarbonate blends / Indose Aravind in Industrial & engineering chemistry research, Vol. 49 N° 8 (Avril 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3873–3882 Titre : Morphology, dynamic mechanical, thermal, and crystallization behaviors of poly(trimethylene terephthalate)/polycarbonate blends Type de document : texte imprimé Auteurs : Indose Aravind, Auteur ; Alain Boumod, Auteur ; Yves Grohens, Auteur Année de publication : 2010 Article en page(s) : pp. 3873–3882 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Morphology  Dynamic  Mechanical  Thermal  Crystallization  Behaviors  Poly  Trimethylene  terephthalate  Polycarbonate Résumé : The phase morphology, dynamic mechanical, thermal, and crystallization behaviors of poly(trimethylene terephthalate) (PTT)/polycarbonate (PC) blends were studied. The phase morphology of the blends, investigated as a function of the composition, indicated a two-phase structure. Dynamic mechanical thermal analysis (DMTA) studies revealed that there is a shift in tan δmax toward each other especially in higher PTT contents. This is attributed to the small number of transesterification reactions most likely to occur under the reaction conditions that are more pronounced at higher PTT content. Thermogravimetric analysis revealed that PTT is more susceptible to thermal degradation than PC. The blends with a higher PC content showed a higher degradation temperature. However, the blends with a higher PTT content exhibited the lowest initial degradation temperature, which might be ascribed to its higher extent of transesterification reaction. The addition of PC to PTT increases the activation energy of the blends, which indicates an improvement in the thermal stability. The crystallization behavior of the blends was analyzed by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The DSC results showed that the crystallization behavior of PTT/PC blends was very much affected by the PC content. The onset and peak crystallization temperatures shifted to lower temperatures and the area of the crystallization exotherm decreased with an increase in the PC content. This suggests that the crystallization process of PTT was suppressed by the presence of PC. WAXD analysis revealed that that the intensity of the crystalline diffraction peaks of PTT decreased with an increase in the PC content in the blends. The amount of transesterification reactions occurring between PTT and PC is quantified by Fourier transform IR techniques; it is found that the amount of copolymer formed as a result of transesterification reactions is small, and hence this merely enhances the compatibility between the components. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901767y [article] Morphology, dynamic mechanical, thermal, and crystallization behaviors of poly(trimethylene terephthalate)/polycarbonate blends [texte imprimé] / Indose Aravind, Auteur ; Alain Boumod, Auteur ; Yves Grohens, Auteur . - 2010 . - pp. 3873–3882. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 8 (Avril 2010) . - pp. 3873–3882 Mots-clés : Morphology  Dynamic  Mechanical  Thermal  Crystallization  Behaviors  Poly  Trimethylene  terephthalate  Polycarbonate Résumé : The phase morphology, dynamic mechanical, thermal, and crystallization behaviors of poly(trimethylene terephthalate) (PTT)/polycarbonate (PC) blends were studied. The phase morphology of the blends, investigated as a function of the composition, indicated a two-phase structure. Dynamic mechanical thermal analysis (DMTA) studies revealed that there is a shift in tan δmax toward each other especially in higher PTT contents. This is attributed to the small number of transesterification reactions most likely to occur under the reaction conditions that are more pronounced at higher PTT content. Thermogravimetric analysis revealed that PTT is more susceptible to thermal degradation than PC. The blends with a higher PC content showed a higher degradation temperature. However, the blends with a higher PTT content exhibited the lowest initial degradation temperature, which might be ascribed to its higher extent of transesterification reaction. The addition of PC to PTT increases the activation energy of the blends, which indicates an improvement in the thermal stability. The crystallization behavior of the blends was analyzed by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The DSC results showed that the crystallization behavior of PTT/PC blends was very much affected by the PC content. The onset and peak crystallization temperatures shifted to lower temperatures and the area of the crystallization exotherm decreased with an increase in the PC content. This suggests that the crystallization process of PTT was suppressed by the presence of PC. WAXD analysis revealed that that the intensity of the crystalline diffraction peaks of PTT decreased with an increase in the PC content in the blends. The amount of transesterification reactions occurring between PTT and PC is quantified by Fourier transform IR techniques; it is found that the amount of copolymer formed as a result of transesterification reactions is small, and hence this merely enhances the compatibility between the components. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901767y

Tensile stress relaxation studies of TiO2 and nanosilica filled natural rubber composites / A. P. Meera in Industrial & engineering chemistry research, Vol. 48 N° 10 (Mai 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 10 (Mai 2009) . - p. 5123 Titre : Tensile stress relaxation studies of TiO2 and nanosilica filled natural rubber composites Type de document : texte imprimé Auteurs : A. P. Meera, Auteur ; Sylvère Said, Auteur ; Yves Grohens, Auteur Année de publication : 2009 Article en page(s) : p. 5123 Note générale : Chemical engineering Addition and correction of the same article in volume 48 n° 7, pp. 3410-3416 Langues : Anglais (eng) En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9005029 [article] Tensile stress relaxation studies of TiO2 and nanosilica filled natural rubber composites [texte imprimé] / A. P. Meera, Auteur ; Sylvère Said, Auteur ; Yves Grohens, Auteur . - 2009 . - p. 5123. Chemical engineering Addition and correction of the same article in volume 48 n° 7, pp. 3410-3416 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 10 (Mai 2009) . - p. 5123 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9005029

Tensile stress relaxation studies of TiO2 and nanosilica filled natural rubber composites / A. P. Meera in Industrial & engineering chemistry research, Vol. 48 N° 7 (Avril 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3410–3416 Titre : Tensile stress relaxation studies of TiO2 and nanosilica filled natural rubber composites Type de document : texte imprimé Auteurs : A. P. Meera, Auteur ; Sylvère Said, Auteur ; Yves Grohens, Auteur Année de publication : 2009 Article en page(s) : pp. 3410–3416 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Natural  rubberTiO2  Nanosilice  Silica-filled  NR  Kohlrausch  equation Résumé : Composites of natural rubber were prepared with TiO2 and nanosilica. The stress relaxation behavior of the composites under tension was studied with reference to the filler loading and strain level. It was observed that the rate of stress relaxation increases with increase in filler loading. The rate of stress relaxation was found to be higher for silica-filled NR compared to TiO2-filled NR. This is due to the high degree of agglomeration in silica compared to titanium dioxide filler. The effect of ageing on the stress decay was also investigated and the rate of stress relaxation was found to decrease after ageing. The experimental curves were fitted with the stretched Kohlrausch equation. From the fitting parameters, the relaxation time and the stretching exponent were estimated in order to understand the mechanism of the relaxation processes in the filled natural rubber composites. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801494s [article] Tensile stress relaxation studies of TiO2 and nanosilica filled natural rubber composites [texte imprimé] / A. P. Meera, Auteur ; Sylvère Said, Auteur ; Yves Grohens, Auteur . - 2009 . - pp. 3410–3416. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3410–3416 Mots-clés : Natural  rubberTiO2  Nanosilice  Silica-filled  NR  Kohlrausch  equation Résumé : Composites of natural rubber were prepared with TiO2 and nanosilica. The stress relaxation behavior of the composites under tension was studied with reference to the filler loading and strain level. It was observed that the rate of stress relaxation increases with increase in filler loading. The rate of stress relaxation was found to be higher for silica-filled NR compared to TiO2-filled NR. This is due to the high degree of agglomeration in silica compared to titanium dioxide filler. The effect of ageing on the stress decay was also investigated and the rate of stress relaxation was found to decrease after ageing. The experimental curves were fitted with the stretched Kohlrausch equation. From the fitting parameters, the relaxation time and the stretching exponent were estimated in order to understand the mechanism of the relaxation processes in the filled natural rubber composites. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801494s