title: Influence of nanopores of MCM-41 and SBA-15 confining (n-BuCp)2ZrCl2 on copolymerization of ethylene-alpha-olefin.
abstract: The effect of nanopore in mesoporous materials confining (n-BuCp),ZrCl2 and methylaluminoxane (MAO) on ethylene-1-hexene and ethylene-1-octene copolymerization was investigated on the basis of the copolymerization results, and the analysis of the supported catalyst and the copolymers. SBA-15 and MCM-41 together with amorphous silica were employed as supports, which are capable of confining (n-BuCp)2ZrCl2 and MAO in the nanopore. The copolymerization activities of MCM-41-supported (n-BuCp)2ZrCl2 were higher than those of SBA-15 and SiO2 although that its Zr content was quite lower than those of SBA-15 and SiO2. SBA-15 and MCM-41 showed a remarkable decrease in BET surface area after confining MAO and (n-BuCp)2ZrCl2 compared to SiO2, explaining an even adsorption of MAO and (n-BuCp)2ZrCl2 complexes on the nanopore surface. Temperature rising elution fractionation (TREF) results showed bimodal curves of MCM-41-supported (n-BuCp)2ZrCl2 at the C6/C2 and C8/C2 molar ratios of 0.6 and 0.5, respectively, which was attributed to the differences in ethylene and alpha-olefin concentrations along with the cylindrical nanopore of MCM-41 due to the narrow nanospace.
authors.affiliation: Department of Chemical Engineering, Kongju National University, Gongju, 314-701, Korea.
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Ko
authors.forename: Jeong Suk
authors.initials: JS
authors.lastname: Lee
authors.forename: Jin-Heong
authors.initials: JH
authors.lastname: Yim
authors.forename: Jong-Ki
authors.initials: JK
authors.lastname: Jeon
authors.forename: Kyeong Youl
authors.initials: KY
authors.lastname: Jung
mesh_terms: D000327:Adsorption; D000475:Alkenes / Q000737:chemistry*; D002712:Chlorides / Q000737:chemistry*; D005030:Ethylenes / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013696:Temperature; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000475:Alkenes; D002712:Chlorides; D005030:Ethylenes; C509968:MCM-41; D009942:Organometallic Compounds; D011108:Polymers; C509969:SBA-15; D012822:Silicon Dioxide; C036216:ethylene; C117224:1-hexene; D015040:Zirconium; C037690:1-octene; C429984:zirconium chloride