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Effect of catalysts supporting on tandem polymerization of ethylene stock in synthesis ofethylene-1-hexene copolymer / Junwei Zhang in Industrial & engineering chemistry research, Vol. 47 n°15 (Août 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5369-5375 Titre : Effect of catalysts supporting on tandem polymerization of ethylene stock in synthesis ofethylene-1-hexene copolymer Type de document : texte imprimé Auteurs : Junwei Zhang, Auteur ; Hong Fan, Auteur ; Bo-Geng Li, Auteur ; Shiping Zhu, Auteur Année de publication : 2008 Article en page(s) : p. 5369-5375 Note générale : Bibliogr. p. 5374-5375 Langues : Anglais (eng) Mots-clés : Ethylene  stock;  Copolymérisation;  polyéthylène Résumé : Ethylene-1-hexene copolymers were synthesized with a tandem catalysis system consisting of a new trimerization catalyst (1), bis(2-dodecylsulfanylethyl)amine-CrCl3, and a copolymerization catalyst (2), Et(Ind)2ZrCl2. Catalysts 1 and 2 were supported on silica particles, and the effects of different supporting strategies on trimerization selectivity, 1-hexene incorporation efficiency, and copolymerization activity were studied and compared to the homogeneous system. It was found that the supported 1 trimerized ethylene with a similar selectivity (>99%) but one-quarter of the activity of the homogeneous 1. The supported 2 gave 40% 1-hexene incorporation efficiency and one-third of the copolymerization activity of the homogeneous 2. The tandem action of the supported 1 and 2 yielded linear low-density polyethylene (LLDPE) materials that contained only C4 side-chains. The dual supported system had activities at a 107 g/(mol Zr h) level, in the same order of the homogeneous counterpart. Adjusting the Cr/Zr ratio yielded various branching densities and, thus, melting temperatures of the resulting polymers. The samples prepared with the supported 2 exhibited broad differential scanning calorimetry (DSC) curves, probably due to multiple active sites. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie7017564 [article] Effect of catalysts supporting on tandem polymerization of ethylene stock in synthesis ofethylene-1-hexene copolymer [texte imprimé] / Junwei Zhang, Auteur ; Hong Fan, Auteur ; Bo-Geng Li, Auteur ; Shiping Zhu, Auteur . - 2008 . - p. 5369-5375. Bibliogr. p. 5374-5375 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°15 (Août 2008) . - p. 5369-5375 Mots-clés : Ethylene  stock;  Copolymérisation;  polyéthylène Résumé : Ethylene-1-hexene copolymers were synthesized with a tandem catalysis system consisting of a new trimerization catalyst (1), bis(2-dodecylsulfanylethyl)amine-CrCl3, and a copolymerization catalyst (2), Et(Ind)2ZrCl2. Catalysts 1 and 2 were supported on silica particles, and the effects of different supporting strategies on trimerization selectivity, 1-hexene incorporation efficiency, and copolymerization activity were studied and compared to the homogeneous system. It was found that the supported 1 trimerized ethylene with a similar selectivity (>99%) but one-quarter of the activity of the homogeneous 1. The supported 2 gave 40% 1-hexene incorporation efficiency and one-third of the copolymerization activity of the homogeneous 2. The tandem action of the supported 1 and 2 yielded linear low-density polyethylene (LLDPE) materials that contained only C4 side-chains. The dual supported system had activities at a 107 g/(mol Zr h) level, in the same order of the homogeneous counterpart. Adjusting the Cr/Zr ratio yielded various branching densities and, thus, melting temperatures of the resulting polymers. The samples prepared with the supported 2 exhibited broad differential scanning calorimetry (DSC) curves, probably due to multiple active sites. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie7017564

Polypropylene and ethylene-propylene copolymer reactor alloys prepared by metallocene/ziegler-natta hybrid catalyst / Lie Lu in Industrial & engineering chemistry research, Vol. 48 N° 18 (Septembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8349–8355 Titre : Polypropylene and ethylene-propylene copolymer reactor alloys prepared by metallocene/ziegler-natta hybrid catalyst Type de document : texte imprimé Auteurs : Lie Lu, Auteur ; Hong Fan, Auteur ; Bo-Geng Li, Auteur Année de publication : 2010 Article en page(s) : pp. 8349–8355 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Polypropylene  Ethylene−propylene  rubber  reactor  Propylene  homopolymerization  Metallocene  activation  Ethylene−propylene  copolymerization Résumé : Polypropylene/ethylene−propylene rubber (PP/EPR) reactor alloys were prepared with a metallocene/Ziegler−Natta hybrid catalyst system (rac-Et(Ind)2ZrCl2/TiCl4/MgCl2) using a process composed of three stages: propylene homopolymerization, metallocene activation, and ethylene−propylene copolymerization. A series of alloy samples were produced and characterized at various copolymerization conditions by varying the methylaluminoxane (MAO)/Zr ratio and monomer composition. It was shown that the metallocene/Ziegler−Natta hybrid system exhibited the features of both metallocene and Ziegler−Natta catalysts during copolymerization. The hybrid catalyst had better ability in incorporating α-olefin than the Ziegler−Natta catalyst owing to the action of metallocene active sites. DSC and IR analyses suggested that EPR in the alloys became random with increased MAO/Zr ratio. In addition, reducing the ethylene content in the feed decreased the activity and promoted the production of random copolymers. An operation window of reaction conditions was identified for the preparation of well-dispersed spherical PP/EPR reactor alloy particles containing up to about 40 wt % EPR. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900579h [article] Polypropylene and ethylene-propylene copolymer reactor alloys prepared by metallocene/ziegler-natta hybrid catalyst [texte imprimé] / Lie Lu, Auteur ; Hong Fan, Auteur ; Bo-Geng Li, Auteur . - 2010 . - pp. 8349–8355. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 18 (Septembre 2009) . - pp. 8349–8355 Mots-clés : Polypropylene  Ethylene−propylene  rubber  reactor  Propylene  homopolymerization  Metallocene  activation  Ethylene−propylene  copolymerization Résumé : Polypropylene/ethylene−propylene rubber (PP/EPR) reactor alloys were prepared with a metallocene/Ziegler−Natta hybrid catalyst system (rac-Et(Ind)2ZrCl2/TiCl4/MgCl2) using a process composed of three stages: propylene homopolymerization, metallocene activation, and ethylene−propylene copolymerization. A series of alloy samples were produced and characterized at various copolymerization conditions by varying the methylaluminoxane (MAO)/Zr ratio and monomer composition. It was shown that the metallocene/Ziegler−Natta hybrid system exhibited the features of both metallocene and Ziegler−Natta catalysts during copolymerization. The hybrid catalyst had better ability in incorporating α-olefin than the Ziegler−Natta catalyst owing to the action of metallocene active sites. DSC and IR analyses suggested that EPR in the alloys became random with increased MAO/Zr ratio. In addition, reducing the ethylene content in the feed decreased the activity and promoted the production of random copolymers. An operation window of reaction conditions was identified for the preparation of well-dispersed spherical PP/EPR reactor alloy particles containing up to about 40 wt % EPR. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900579h

Preparation and CO2 sorption/desorption of N - (3 - aminopropyl) aminoethyl tributylphosphonium amino acid salt ionic liquids supported into porous silica particles / Jie Ren in Industrial & engineering chemistry research, Vol. 51 N° 23 (Juin 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 23 (Juin 2012) . - pp. 7901–7909 Titre : Preparation and CO2 sorption/desorption of N - (3 - aminopropyl) aminoethyl tributylphosphonium amino acid salt ionic liquids supported into porous silica particles Type de document : texte imprimé Auteurs : Jie Ren, Auteur ; Linbo Wu, Auteur ; Bo-Geng Li, Auteur Année de publication : 2012 Article en page(s) : pp. 7901–7909 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic  liquids  Porous  silica Résumé : To search for robust CO2 capture materials, several N-(3-aminopropyl)aminoethyl tributylphosphonium amino acid salts ([apaeP444][AA])-type task specific ionic liquids (TSILs) were synthesized and immobilized into porous silica support through a facile impregnation–vaporization method. The ILs and thus prepared sorbents, Sorb-AA, were well characterized, and their CO2 sorption and desorption behaviors under temperature- and vacuum-swing conditions were investigated. The ILs can be immobilized facilely into silica up to 1/1 IL/SiO2 weight ratio. After IL loading, the sorbents retain reasonably high specific surface area and porosity and therefore exhibit rapid sorption and desorption rates as well as excellent sorption capacity and selectivity and can be used repeatedly. Among them, Sorb-Lys has the highest CO2 sorption capacity. It can capture 1.54 mmol or 67.9 mg CO2 per gram sorbent from a simulated flue gas containing 14% CO2 in each cycle of sorption and desorption. Sorb-Gly has slightly less CO2 sorption capacity, 1.37 mmol or 60.4 mg CO2 per gram sorbent from the simulated flue gas, and much better long-term durability. It is estimated that it can retain 90% sorption capacity even after 1.38 × 103 cycles. These robust sorbents, especially Sorb-Gly, exhibit excellent potential in CO2 capture applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2028415 [article] Preparation and CO2 sorption/desorption of N - (3 - aminopropyl) aminoethyl tributylphosphonium amino acid salt ionic liquids supported into porous silica particles [texte imprimé] / Jie Ren, Auteur ; Linbo Wu, Auteur ; Bo-Geng Li, Auteur . - 2012 . - pp. 7901–7909. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 23 (Juin 2012) . - pp. 7901–7909 Mots-clés : Ionic  liquids  Porous  silica Résumé : To search for robust CO2 capture materials, several N-(3-aminopropyl)aminoethyl tributylphosphonium amino acid salts ([apaeP444][AA])-type task specific ionic liquids (TSILs) were synthesized and immobilized into porous silica support through a facile impregnation–vaporization method. The ILs and thus prepared sorbents, Sorb-AA, were well characterized, and their CO2 sorption and desorption behaviors under temperature- and vacuum-swing conditions were investigated. The ILs can be immobilized facilely into silica up to 1/1 IL/SiO2 weight ratio. After IL loading, the sorbents retain reasonably high specific surface area and porosity and therefore exhibit rapid sorption and desorption rates as well as excellent sorption capacity and selectivity and can be used repeatedly. Among them, Sorb-Lys has the highest CO2 sorption capacity. It can capture 1.54 mmol or 67.9 mg CO2 per gram sorbent from a simulated flue gas containing 14% CO2 in each cycle of sorption and desorption. Sorb-Gly has slightly less CO2 sorption capacity, 1.37 mmol or 60.4 mg CO2 per gram sorbent from the simulated flue gas, and much better long-term durability. It is estimated that it can retain 90% sorption capacity even after 1.38 × 103 cycles. These robust sorbents, especially Sorb-Gly, exhibit excellent potential in CO2 capture applications. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2028415