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α‐Diimine nickel catalyst for copolymerization of hexene and acrylate monomers activated by different cocatalysts
Author(s) -
Avar Sajad,
Mortazavi Seyed Mohammad Mahdi,
Ahmadjo Saeid,
Zohuri Gholam Hossein
Publication year - 2018
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.4238
Subject(s) - comonomer , chemistry , polymer chemistry , monomer , copolymer , hexene , organic chemistry , polymer
Bulk homopolymerization and copolymerization of 1‐hexene (H) with polar monomers including butyl acrylate (B) and methyl methacrylate (M) in the presence of 1,4‐bis (2,6‐diisopropylphenyl) acenaphthene diimine nickel (II) dibromide catalyst were investigated. Two cocatalysts, including diethyl aluminium chloride (DEAC) and ethyl aluminium sesqui chloride (EASC), were used to activate the catalyst at ambient temperature. In both the homopolymerization and copolymerization of 1‐hexene with polar monomers, the catalyst activity resulted from EASC as cocatalyst was higher than that resulted from DEAC. 1 HNMR analysis was used in order to determine incorporation level of polar monomers and branching density of the synthesized polymers. A highest incorporation level of 13.3% mol was obtained using monomer B in the presence of the cocatalyst EASC. In addition, the influence of polar monomers on molecular weight and molecular weight distribution (PDI) was studied for both the homo‐ and co‐polymerizations of 1‐hexene in the presence of various cocatalysts. A higher molecular weight and narrower PDI were obtained by using the DEAC cocatalyst compared to the EASC cocatalyst. Glass transition temperature (Tg) and melting point (Tm) of the synthesized polymers were found to be dependent on the cocatalyst type and comonomer incorporation level. The addition of dichloromethane solvent into reaction medium showed a positive effect on comonomer incorporation which could not be seen in bulk polymerization. However, the presence of dichloromethane led to decrease the catalyst activity and molecular weight of the polymers.