Determination of the residence time distribution in twin Screw extruders via free radical modification of PE / M. K. RazaviAghjeh in INTERNATIONAL POLYMER PROCESSING, Vol. XIX, N° 4 (12/2004)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XIX, N° 4 (12/2004) . - p. 335-341 Titre : Determination of the residence time distribution in twin Screw extruders via free radical modification of PE Type de document : texte imprimé Auteurs : M. K. RazaviAghjeh, Auteur ; Hossein Nazockdast, Auteur ; H. Assempour, Auteur Année de publication : 2004 Article en page(s) : p. 335-341 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : The main objective of the present work was to introduce an inline method for measuring the residence time distribution (RTD) of twin screw extruders on the basis of information obtained from the melt free radical modification of polyethylene in a modular intermeshing co-rotating twin screw extruder. The trend of increasing rate of the extruder total torque resulted from replacing the neat polyethylene feed by a mixture of polyethylene and reactants which are chemically capable of creating chainbranching and/or crosslinking reactions was considered as the main information source for evaluating the RTD of the extruder. The RTD results were compared with those obtained from the tracer pulse input method, and good agreement was found. It was also demonstrated that, the present in-line RTD measuring technique has reliability of following the effect of feeding rate, screw speed and reactant concentration on the RTD of the twin screw extruders. It was found that, increasing the feeding rate results in decreasing the minimum residence time, and results in a narrower RTD. At constant feeding rate increasing the screw speed decreased the minimum residence time and broadened the RTD. The results also showed that, reactant concentration and variation of the viscosity along the screw have not appreciable effect on the twin screw extruders RTD. DOI : 10.3139/217.1842 En ligne : https://drive.google.com/file/d/1wrPVMP4aQXntatHiToIO_V1cSVa4BneJ/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3265 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
001030	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Effect of nanoclay surface modifier chemical reactivity on morphology and rheological properties of PP/PA6 blend nanocomposite / G. R. Pircheraghi in INTERNATIONAL POLYMER PROCESSING, Vol. XXVIII, N° 4 (08/2013)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXVIII, N° 4 (08/2013) . - p. 354-360 Titre : Effect of nanoclay surface modifier chemical reactivity on morphology and rheological properties of PP/PA6 blend nanocomposite Type de document : texte imprimé Auteurs : G. R. Pircheraghi, Auteur ; Hossein Nazockdast, Auteur ; M. M. Salehi, Auteur Année de publication : 2013 Article en page(s) : p. 354-360 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Alliages polymères Argile Cations Diamine Une diamine est un type de polyamine contenant exactement deux groupes amine. Les diamines sont principalement utilisées comme monomères pour synthétiser des polyamides, des polyimides et des polyurées. La principale diamine produite est le 1,6-diaminohexane, précurseur du Nylon 6-6, suivie de l'éthylènediamine1. L'hydrazine (H2NNH2) n'est en général pas considérée comme une diamine puisque ce n'est ni une amine (pas de carbone), ni une dibase. Morphologie (matériaux) Nanoparticules Polyamide 6 Polypropylène Rhéologie Traîtements de surface Index. décimale : 668.4 Plastiques, vinyles Résumé : An attempt was made to explore the role of nanoclay surface modifier chemical reactivity on the morphology and the rheological properties of a polypropylene/polyamide6 (PP/PA6 75/25) nanocomposite blend. The Na-MMT surface was modified with two types of cations; a) diamine cation (D-Clay), and b) a combination of diamine and quaternary alkylammonium cations (A-Clay) via cation exchange reaction. The „nanocomposites samples compatibilized with PP-g-MA were prepared by melt compounding in an internal mixer. The XRD patterns indicated the intercalated/exfoliated microstructure for both nanocomposite samples. The SEM results showed a significant decreases in the PA6 droplet size, from 3.2?m of the simple blend to the 0.4?m in the D-Clay containing sample. Moreover, in the sample containing A-Clay the average droplet size was found to be 1?m. The D-Clay containing sample showed the rheological properties similar to a simple blend in high frequencies with a nonterminal be„havior in low frequencies storage modulus. This was explained by locating of D-Clay layers in the interphase and hence, significantly reducing the effective interfacial tension, ?/R. In contrast, the sample containing A-Clay showed an increased complex viscosity and storage modulus within a range of frequencies, which was attributed to presence of a large amount of A-Clay layers in the PP matrix. These types of nanoclay partitioning were explained by the possibility of chemical reaction between amine group of nanoclay surface modifier and maleic group of PP-g-MA compatibilizer or in-situ formed block copolymer. Consequently, the D-Clay layers bounded with PP-g-MA is preferentially located in the interphase, while, the non reactive nanoclay layers (containing alkylammonium cations) is dispersed in the PP matrix by assistance of PP-g-MA. These findings were also evidenced by TEM micrograph of both nanocomposite samples. Note de contenu : - EXPERIMENTAL/MODELING/SIMULATION : Materials - Na-MMT surface modification - Nanocomposite preparation - CHARACTERIZATION DOI : 10.3139/217.2680 En ligne : https://drive.google.com/file/d/1_UVNJId8hAvNEJDYdeG9PJdPTXD622Ly/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=19279 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
15396	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Prediction of residence time distribution for different screw configurations of a ko-kneader by using a cluster model / M. Mehranpour in INTERNATIONAL POLYMER PROCESSING, Vol. XIX, N° 1 (03/2004)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XIX, N° 1 (03/2004) . - p. 13-15 Titre : Prediction of residence time distribution for different screw configurations of a ko-kneader by using a cluster model Type de document : texte imprimé Auteurs : M. Mehranpour, Auteur ; B. Dabir, Auteur ; Hossein Nazockdast, Auteur Année de publication : 2004 Article en page(s) : p. 13-15 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : Prediction of residence time distribution (RTD) in the modular type screw extruders has always been one of the most attractive subjects for predicting. In the present work an attempt was made to establish a method with functionality similar to additive rule for predicting RTD of the modular screw extruders with different configurations such as Buss Ko-Kneader. Results predicted from this method, which was named as cluster model, were compared with the results predicted based on our previously reported trajectory method as well as experimental results. A reasonability good agreement was found between these results justified reliability of the cluster model for being used as a new approach to predict the RTD of the modular screw extruders. DOI : 10.3139/217.1758 En ligne : https://drive.google.com/file/d/1T-seYCJq3-4qX5K-yQStJxdihSjaIKxV/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3289 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
001027	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Preparation and characterization of HMW PA 6 via anionic polymerization of E-caprolactam by using a mixture of di- and tri-functional chain initiators / M. M. S. Barmi in INTERNATIONAL POLYMER PROCESSING, Vol. XXI, N° 3 (07/2006)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXI, N° 3 (07/2006) . - p. 230-238 Titre : Preparation and characterization of HMW PA 6 via anionic polymerization of E-caprolactam by using a mixture of di- and tri-functional chain initiators Type de document : texte imprimé Auteurs : M. M. S. Barmi, Auteur ; H. Assempour, Auteur ; Hossein Nazockdast, Auteur Année de publication : 2006 Article en page(s) : p. 230-238 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : In the present work, an attempt was made to synthesis polyamide 6 through anionic polymerization of e-Caprolactam by using a mixture of Diphenylmethan 4, 40-di and tri-isocyanate as a chain initiator and sodium caprolactamate as a catalyst. Polymerization was carried out in a laboratory internal mixer (Brabender). The rotor speed, reaction temperature and reaction time were among the processing variables studied. The prepared samples were characterized by Thermogravimetry Analysis (TGA), Differential Scanning Calorimeter (DSC) and FT-IR spectroscopy. The flow behavior and melt viscoelastic properties of the samples were studied by using a Rheometric Mechanical Spectrometer (RMS). The polymerization reaction was found to be very fast and was completed within 6 minutes. This was detected by following the mixing torque which reached to a steady state after passing through a maximum. The pronounced decrease in the torque was found to be determine by the thermomechanical degradation as a predominating mechanism. The polyamide 6 prepared in this work showed greater melt elasticity, much higher molecular weight and slightly narrower molecular weight distribution in comparison with the commercial grades of polyamide 6. The crystallinity of the samples was also higher than that of the commercial polyamide 6. These results were explained in terms of contribution of fraction of the molecules possessing single long chain branch formed as a result of three functional nature of the chain initiator. Increasing the rotor speed was found to have strong influence on lowering molecular weight as well as narrowing the molecular weight distribution through increasing the extent of thermomechanical degradation. Increasing the initial set temperature in the studied range had no appreciable effect on polymerization rate and degree of conversion. It was demonstrated that the results of melt viscoelastic measurements performed on the samples collected at different polymerization times can provide valuable information to follow the polymerization reaction. DOI : 10.3139/217.0074 En ligne : https://drive.google.com/file/d/16l2AvStFSEhR-K5Y1jBSM_D6WtNcDAEh/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=2837 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
005042	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Rheology of polypropylene/liquid crystalline polymer blends : effect of compatibilizer and silica / Reza Foudazi in APPLIED RHEOLOGY, Vol. 20, N° 1 (2010)

[article]  inAPPLIED RHEOLOGY > Vol. 20, N° 1 (2010) . - 9 p. Titre : Rheology of polypropylene/liquid crystalline polymer blends : effect of compatibilizer and silica Type de document : texte imprimé Auteurs : Reza Foudazi, Auteur ; Hossein Nazockdast, Auteur Année de publication : 2010 Article en page(s) : 9 p. Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Alliages polymères Nanoparticules polymères cristaux liquides Polypropylène Rhéologie Silice La silice est la forme naturelle du dioxyde de silicium (SiO2) qui entre dans la composition de nombreux minéraux. La silice existe à l'état libre sous différentes formes cristallines ou amorphes et à l'état combiné dans les silicates, les groupes SiO2 étant alors liés à d'autres atomes (Al : Aluminium, Fe : Fer, Mg : Magnésium, Ca : Calcium, Na : Sodium, K : Potassium...). Les silicates sont les constituants principaux du manteau et de l'écorce terrestre. La silice libre est également très abondante dans la nature, sous forme de quartz, de calcédoine et de terre de diatomée. La silice représente 60,6 % de la masse de la croûte terrestre continentale. Index. décimale : 668.9 Polymères Résumé : L'effet d'additifs classiques et de charges de silice, qui représentent potentiellement un nouveau type d'additifs pour rendre compatibles des mélanges de polymères, sur les propriétés rhéologiques de mélanges PP/LCP a été étudié. Des balayages en fréquence, des montées en contrainte de cisaillement et des relaxations de contraintes après cessation de cisaillement en régime établi ont été effectués afin d'explorer l'effet de la modification de l'interface et le rôle de la silice sur le comportement rhéologique du mélange. On a trouvé que les SEBS-g-MA améliore l'interaction à l'interface encore mieux que le SEBS. Ceci est du à de possibles liaisons chimiques entre les groupes d'anhydride maléique et les chaînes de LCP. Les résultats montrent que la silice hydrophobe à un effet de liant sur les échantillons de mélanges PP/LCP, tandis que la silice hydrophile remplit à la fois la matrice et la phase dispersée de LCP. Note de contenu : EXPERIMENTAL : Materials - Blend preparation - Morphological studies - Rhelogical measurements. RESULTS AND DISCUSSION : Morphology - Linear viscoelastic properties - Transient shear flow measurements. Référence de l'article : 12218 DOI : 10.3933/ApplRheol-20-12218 Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9037 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
012074	-	Périodique	Bibliothèque principale	Documentaires	Disponible

The role of nanoclay partitioning and fibril formation on dyeability of blend nanocomposite fibres / Ahmad Bigdeli in COLORATION TECHNOLOGY, Vol. 129, N° 4 (08/2013)  

Permalink

The role of organoclay on in-situ microfibril formation of epoxy in poly(butylene terephtalate) nanocomposites / M. M. Salehi in INTERNATIONAL POLYMER PROCESSING, Vol. XXVIII, N° 2 (05/2013)  

Permalink

---

1 (1 - 7 / 7)