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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

Rheology, morphology, mechanical properties and free volume of poly(trimethylene terephthalate)/polycarbonate blends / Indose Aravind in Industrial & engineering chemistry research, Vol. 48 N° 22 (Novembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 22 (Novembre 2009) . - pp. 9942–9951 Titre : Rheology, morphology, mechanical properties and free volume of poly(trimethylene terephthalate)/polycarbonate blends Type de document : texte imprimé Auteurs : Indose Aravind, Auteur ; Kyung Hyun Ahn, Auteur ; C. Ranganathaiah, Auteur Année de publication : 2010 Article en page(s) : pp. 9942–9951 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : poly(trimethylene  terephthalate)/polycarbonate  blends  Rheological  measurements Résumé : The phase morphology, rheology, mechanical properties, and free volume of poly(trimethylene terephthalate)/polycarbonate (PTT/PC) blends have been investigated as a function of composition. The morphology indicated a two-phase structure, and the blends showed co continuous phase morphology between 30−60 wt % of poly carbonate. Due to the high viscosity of PC, PTT is more finely dispersed in the PC matrix than PC in the PTT matrix. The rheological measurements of the blends revealed that the complex viscosity increased with increase in PC content. Relatively low interfacial tension values of the blends determined using Palierne and Choi−Schowalter methods indicated that there is considerable interaction between the blend components (PTT and PC) due to the transesterification reactions. A random copolyester formed as a result of the transesterification acted as a compatibilizer in the initial stages of reactions which is the main factor for the change in miscibility. The phase morphology and the interfacial adhesion influence the mechanical properties such that addition of the PC phase decreases the tensile strength and Young’s modulus of the system. The free volume data from PALS results showed a slight positive deviation from the known linear additivity rule with increase in PC content, suggesting the blends are partially miscible. Our results show a good correlation among the phase morphology, rheology, mechanical, and free volume parameters. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007503 [article] Rheology, morphology, mechanical properties and free volume of poly(trimethylene terephthalate)/polycarbonate blends [texte imprimé] / Indose Aravind, Auteur ; Kyung Hyun Ahn, Auteur ; C. Ranganathaiah, Auteur . - 2010 . - pp. 9942–9951. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 22 (Novembre 2009) . - pp. 9942–9951 Mots-clés : poly(trimethylene  terephthalate)/polycarbonate  blends  Rheological  measurements Résumé : The phase morphology, rheology, mechanical properties, and free volume of poly(trimethylene terephthalate)/polycarbonate (PTT/PC) blends have been investigated as a function of composition. The morphology indicated a two-phase structure, and the blends showed co continuous phase morphology between 30−60 wt % of poly carbonate. Due to the high viscosity of PC, PTT is more finely dispersed in the PC matrix than PC in the PTT matrix. The rheological measurements of the blends revealed that the complex viscosity increased with increase in PC content. Relatively low interfacial tension values of the blends determined using Palierne and Choi−Schowalter methods indicated that there is considerable interaction between the blend components (PTT and PC) due to the transesterification reactions. A random copolyester formed as a result of the transesterification acted as a compatibilizer in the initial stages of reactions which is the main factor for the change in miscibility. The phase morphology and the interfacial adhesion influence the mechanical properties such that addition of the PC phase decreases the tensile strength and Young’s modulus of the system. The free volume data from PALS results showed a slight positive deviation from the known linear additivity rule with increase in PC content, suggesting the blends are partially miscible. Our results show a good correlation among the phase morphology, rheology, mechanical, and free volume parameters. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007503