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Study on single and binary catalytic systems of pyridine‐imine catalysts based on nickel and iron in synthesis of reactor blends and low‐density polyethylene nanocomposites
Author(s) -
Mogheiseh Mohsen,
Zohuri Gholam Hossein,
Khoshsefat Mostafa
Publication year - 2019
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.47376
Subject(s) - materials science , polyethylene , crystallinity , catalysis , nanocomposite , thermal stability , polymer chemistry , pyridine , monomer , low density polyethylene , thermogravimetric analysis , polymerization , chemical engineering , composite material , polymer , chemistry , organic chemistry , engineering
In the presence of modified methylaluminoxane as cocatalyst, the behavior of a binary catalytic system based on pyridine‐imine nickel ( N ) and iron ( F ) catalysts was evaluated in order to reach a proper mixture of polyethylene (PE). A computational study along with kinetic profile suggested that the catalyst F with higher electron affinity ( A ) and electrophilicity (ω) in the methyl cationic active center and stronger interaction with the monomer led to high integrated monomer consumption and higher activity. In addition, the samples produced by the mixture of catalysts showed a higher value ofM ¯ v [19.4 × 10 4 g (PE) mol (Fe+Ni) −1 h −1 )], melting point (127.8 °C), and crystallinity extent (41.29%) than the samples produced by the single catalysts. The addition of multiwalled carbon nanotubes (MWCNT) into the polymerization media reduced the activity of catalysts [from 7.50 × 10 4 to 0.66 × 10 4 g (PE) mol (Fe+Ni) −1 h −1 ] and the thermal properties of the low‐density polyethylene nanocomposite samples. However, the sample containing 2.33% MWCNT 20‐30 improved the total thermal stability of the neat polyethylene blend up to 400 °C. Scanning electron microscope images of the samples demonstrated irregular to virtually uniform morphologies were obtained through the in situ and solution‐mixing techniques. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47376.