Analysis of the morphological development of PBT/ABS blends during the twin screw extrusion and injection molding processes / E. N. Ito in INTERNATIONAL POLYMER PROCESSING, Vol. XVIII, N° 4 (12/2003)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XVIII, N° 4 (12/2003) . - p. 376 - 381 Titre : Analysis of the morphological development of PBT/ABS blends during the twin screw extrusion and injection molding processes Type de document : texte imprimé Auteurs : E. N. Ito, Auteur ; L. A. Pessan, Auteur ; Jose A. Covas, Auteur ; E. Hage, Auteur Année de publication : 2003 Article en page(s) : p. 376 - 381 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : Molding - The aim of this work was to observe the development of the phase morphology of the PBT/ABS blends during their extrusion mixing and injection molding steps. The evolution of the blend morphology during the mixing stage was analyzed using a specially designed co-rotational twin-screw extruder with a collecting device located along the barrel. Blend samples were collected inline along the length of the extruder barrel during the blending process. Samples obtained from the extruded pellets and from injection molded specimens were also used to observe the blend morphology. All the samples were observed by transmission electron microscopy (TEM). They were prepared by cryo-ultramicrotomy and the rubbery phase of the ABS contained in the blends was stained with osmium tetroxide (OsO4). A special function was established and is proposed to analyze the blend morphology trends through image analysis. In binary blends, the ABS phase showed better dispersion after the mixture passed through the extruder die. However, a coalescence phenomenon was observed during the next molding step. Compatibilized PBT/ABS blends showed better dispersion than binary blends, even after injection molding. The special function used to quantify the dispersion throughout the mixing and molding steps showed an excellent performance. Note de contenu : - MATERIALS AND METHODS : Materials - Equipment - Preparation Methods to Observe Phase Morphology - RESULTS AND DISCUSSION : Image Analyses - Morphological Development DOI : 10.3139/217.1780 En ligne : https://drive.google.com/file/d/1wyJ5zIXbkY4E7VZvZLpgAFI4VaeUlDLd/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15821 [article]

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Effect of blending protocol on the rheological properties and morphology of HDPE and LLDPE blend-based nanocomposites / Fabio R. Passador in INTERNATIONAL POLYMER PROCESSING, Vol. XXVII, N° 3 (07/2012)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXVII, N° 3 (07/2012) . - p. 378-385 Titre : Effect of blending protocol on the rheological properties and morphology of HDPE and LLDPE blend-based nanocomposites Type de document : texte imprimé Auteurs : Fabio R. Passador, Auteur ; Adhemar C. Ruvolo-Filho, Auteur ; L. A. Pessan, Auteur Année de publication : 2012 Article en page(s) : p. 378-385 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Alliages polymères Anhydride maléique Matériaux hybrides Montmorillonite Polyéthylène basse densité linéaire Polyéthylène haute densité Rhéologie Structure cristalline (solide) Index. décimale : 668.4 Plastiques, vinyles Résumé : Nanocomposites based on high density polyethylene (HDPE)/linear low density polyethylene (LLDPE) blend were prepared by melt compounding in a torque rheometer using an organoclay (montmorillonite) as nano-filler and maleic anhydridegrafted linear low density polyethylene (LLDPE-g-MA) as compatibilizer. The effects of five blending protocols on microstructure, crystallinity and rheological properties of the prepared samples were examined. The steady state rheological properties showed that the addition of nanoclay to the HDPE/LLDPE blend increased its shear viscosity at low shear rates changing the behavior of the HDPE/LLDPE matrix to a more pronounced shear thinning behavior. The blending sequence (LLDPE/LLDPE-g-MA/20A)/HDPE (where LLDPE and LLDPE-g-MA were first mixed with organoclay and then this system was later blended with HDPE) showed a lower slope of the log g versus log γ curve and these results can be an indicative that the interactions between the matrix and the organoclay are stronger. The organoclay interlayer spacing and the crystallinity of the polymer domains were also influenced by the blending sequence. The crystallinity was calculated through the mathematical deconvolution of the peaks observed in the WAXD profiles. Overall, the crystallization of HDPE in the blends was hardly influenced by the presence of LLDPE. The blending sequence (LLDPE/LLDPE-g-MA/20A)/HDPE showed lower cristallinity when compared to others blending sequences. On the other hand, it was observed an increase in the organoclay interlayer spacing of this nanocomposite because the intercalation and/or exfoliation process occurs preferentially in the amorphous phase. DOI : 10.3139/217.2567 En ligne : https://drive.google.com/file/d/1lIQb9pM2Akh7QBUAGlF6qeWHZhiQIMFK/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15584 [article]

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Influence of blending protocol on the thermal and mechanical properties of HDPE/LLDPE blend-based nanocomposites / Fabio R. Passador in INTERNATIONAL POLYMER PROCESSING, Vol. XXXI, N° 4 (08/2016)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXXI, N° 4 (08/2016) . - p. 472-481 Titre : Influence of blending protocol on the thermal and mechanical properties of HDPE/LLDPE blend-based nanocomposites Type de document : texte imprimé Auteurs : Fabio R. Passador, Auteur ; Adhemar C. Ruvolo-Filho, Auteur ; L. A. Pessan, Auteur Année de publication : 2016 Article en page(s) : p. 472-481 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Alliages polymères Alliages polymères -- propriétés mécaniques Alliages polymères -- Propriétés thermiques Anhydride maléique Charges (matériaux) Copolymères greffés Matériaux hybrides -- Propriétés mécaniques Matériaux hybrides -- Propriétés thermiques Montmorillonite Nanoparticules Polyéthylène basse densité linéaire Polyéthylène haute densité Polyéthylène maléate Rhéométrie Index. décimale : 668.4 Plastiques, vinyles Résumé : Nanocomposites based on high density polyethylene (HDPE)/linear low density polyethylene (LLDPE) blend were prepared by melt compounding in a twin-screw extruder using an organoclay (montmorillonite) as nano-filler and maleic anhydride-grafted linear low density polyethylene (LLDPE-g-MA) as compatibilizer. The effects of two blending protocols were also investigated. In the first blending protocol LLDPE and LLDPE-g-MA were first reinforced with organoclay and then this nanocomposite was later blended with HDPE, and the second blending protocol LLDPE-g-MA was mixed with organoclay first and then this masterbatch was diluted with HDPE and LLDPE. The preparation of the masterbatch resulted in the degradation of polyethylene, with crosslinking formation which increase the viscosity of the polymer and facilitated the dispersion of the organoclay in the polymeric matrix. WAXD and TEM were used to determine the effect of blending protocol and organoclay content on the intercalation and mechanical properties. The introduction of a maleated polyethylene was required to improve the organoclay dispersion in the nanocomposites. Thermal and mechanical properties of the nanocomposites were affected by blending protocols and the content of organoclay. The degree of crystallinity of the materials prepared using the first blending protocol decreased upon the intercalation of clay platelets whereas for the materials obtained using the second blending protocol the degree of crystallinity decreased due the crosslinking which further restricted mobility and diffusion of polymer chains. The nanocomposites show higher values of tensile modulus, flexural modulus and HDT compared to the blend without the addition of organoclay. The OMMT content added to the polymer blend results in significant and well correlated improvements in tensile and flexural moduli. Note de contenu : - EXPERIMENTAL : Materials - Melt processing - Swelling measurements - Nanocomposite preparation - Characterization of the nanocomposites - RESULTS AND DISCUSSION : Rheometric torque curves - WAXD and TEM analysis - Thermal properties - Mechanical properties DOI : 10.3139/217.3238 En ligne : https://drive.google.com/file/d/1SjcBsX-9U4ulsD2GK9mQjCy-2SsOns42/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=26809 [article]

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