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( n BuCp) 2 ZrCl 2 ‐catalyzed ethylene‐4M1P copolymerization: Copolymer backbone structure, melt behavior, and crystallization
Author(s) -
Atiqullah Muhammad,
Adamu Sagir,
Malaibari Zuhair O.,
AlHarthi Mamdouh A.,
Emwas AbdulHamid M.
Publication year - 2016
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.15159
Subject(s) - copolymer , methylaluminoxane , ethylene , metallocene , polymer chemistry , polyethylene , crystallization , materials science , post metallocene catalyst , catalysis , polymerization , chemistry , organic chemistry , polymer
The judicious design of methylaluminoxane (MAO) anions expands the scope for developing industrial metallocene catalysts. Therefore, the effects of MAO anion design on the backbone structure, melt behavior, and crystallization of ethylene−4‐methyl‐1‐pentene (E−4M1P) copolymer were investigated. Ethylene was homopolymerized, as well as copolymerized with 4M1P, using (1) MAO anion A (unsupported [MAOCl 2 ] − ) premixed with dehydroxylated silica, ( n BuCp) 2 ZrCl 2 , and Me 2 SiCl 2 ; and (2) MAO anion B (Si−O−Me 2 Si−[MAOCl 2 ] − ) supported with ( n BuCp) 2 ZrCl 2 on Me 2 SiCl 2 ‐functionalized silica. Unsupported Me 2 SiCl 2 , opposite to the supported analogue, acted as a co‐chain transfer agent with 4M1P. The modeling of polyethylene melting and crystallization kinetics, including critical crystallite stability, produced insightful results. This study especially illustrates how branched polyethylene can be prepared from ethylene alone using particularly one metallocene‐MAO ion pair, and how a compound, that functionalizes silica as well as terminates the chain, can synthesize ethylene−α‐olefin copolymers with novel structures. Hence, it unfolds prospective future research niches in polyethyne systhesis. © 2016 American Institute of Chemical Engineers AIChE J , 62: 1688–1706, 2016