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Auteur George W. Roberts |
Documents disponibles écrits par cet auteur (2)



Effect of polymer size on heterogeneous catalytic polystyrene hydrogenation / Laura Beth Dong in Industrial & engineering chemistry research, Vol. 49 N° 22 (Novembre 2010)
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Titre : Effect of polymer size on heterogeneous catalytic polystyrene hydrogenation Type de document : texte imprimé Auteurs : Laura Beth Dong, Auteur ; Salomon Turgman-Cohen, Auteur ; George W. Roberts, Auteur Année de publication : 2011 Article en page(s) : pp. 11280–11286 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrogenation Catalytic reaction Résumé : The effect of polymer coil size on the rate of polystyrene (PS) hydrogenation was studied in a slurry reactor with mixtures of decahydronaphthalene (DHN) and carbon dioxide (CO2) as the solvent for the polymer. The PS coil size was changed by varying the polymer molecular weight from 9300 g/mol to 357 000 g/mol and by varying the CO2 concentration. Using a 5% Pd/5% Ru/SiO2 catalyst, the rate of aromatic ring hydrogenation at 150 °C was found to be strongly dependent on the size of a polymer coil relative to the average pore diameter of the catalyst. Significant pore diffusion limitations, as indicated by values of the Weisz modulus, were observed with increasing polymer molecular weight. Increasing the concentration of CO2 resulted in increased reaction rates, with an improvement of nearly 2 orders of magnitude at the highest PS molecular weight. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23437823
in Industrial & engineering chemistry research > Vol. 49 N° 22 (Novembre 2010) . - pp. 11280–11286[article] Effect of polymer size on heterogeneous catalytic polystyrene hydrogenation [texte imprimé] / Laura Beth Dong, Auteur ; Salomon Turgman-Cohen, Auteur ; George W. Roberts, Auteur . - 2011 . - pp. 11280–11286.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 22 (Novembre 2010) . - pp. 11280–11286
Mots-clés : Hydrogenation Catalytic reaction Résumé : The effect of polymer coil size on the rate of polystyrene (PS) hydrogenation was studied in a slurry reactor with mixtures of decahydronaphthalene (DHN) and carbon dioxide (CO2) as the solvent for the polymer. The PS coil size was changed by varying the polymer molecular weight from 9300 g/mol to 357 000 g/mol and by varying the CO2 concentration. Using a 5% Pd/5% Ru/SiO2 catalyst, the rate of aromatic ring hydrogenation at 150 °C was found to be strongly dependent on the size of a polymer coil relative to the average pore diameter of the catalyst. Significant pore diffusion limitations, as indicated by values of the Weisz modulus, were observed with increasing polymer molecular weight. Increasing the concentration of CO2 resulted in increased reaction rates, with an improvement of nearly 2 orders of magnitude at the highest PS molecular weight. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23437823 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire Synthesis of cross - linked, partially neutralized poly (Acrylic Acid) by suspension polymerization in supercritical carbon dioxide / Yazan A. Hussain in Industrial & engineering chemistry research, Vol. 51 N° 35 (Septembre 2012)
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Titre : Synthesis of cross - linked, partially neutralized poly (Acrylic Acid) by suspension polymerization in supercritical carbon dioxide Type de document : texte imprimé Auteurs : Yazan A. Hussain, Auteur ; Tao Liu, Auteur ; George W. Roberts, Auteur Année de publication : 2012 Article en page(s) : pp. 11401-11408 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Supercritical state Carbon dioxide Suspension polymerization Résumé : A novel process for producing superabsorbent polymer of cross-linked, partially neutralized poly(acrylic acid) via suspension polymerization in supercritical carbon dioxide was developed. The process utilized siloxane-based surfactants as suspension stabilizers to produce particles with acceptable size range for commercial applications. The behavior of the suspension mixture and its relation to the final product morphology is discussed. The product performance in terms of water absorbency is presented. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26324789
in Industrial & engineering chemistry research > Vol. 51 N° 35 (Septembre 2012) . - pp. 11401-11408[article] Synthesis of cross - linked, partially neutralized poly (Acrylic Acid) by suspension polymerization in supercritical carbon dioxide [texte imprimé] / Yazan A. Hussain, Auteur ; Tao Liu, Auteur ; George W. Roberts, Auteur . - 2012 . - pp. 11401-11408.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 35 (Septembre 2012) . - pp. 11401-11408
Mots-clés : Supercritical state Carbon dioxide Suspension polymerization Résumé : A novel process for producing superabsorbent polymer of cross-linked, partially neutralized poly(acrylic acid) via suspension polymerization in supercritical carbon dioxide was developed. The process utilized siloxane-based surfactants as suspension stabilizers to produce particles with acceptable size range for commercial applications. The behavior of the suspension mixture and its relation to the final product morphology is discussed. The product performance in terms of water absorbency is presented. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26324789 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire