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Tailoring Hexagonal Gibbsite Single Crystal Nanoplatelets for Ethylene Polymerization and Nanocomposite Formation on MAO‐Free Heterogeneous Bis(imino)pyridine Iron(II) Catalyst
Author(s) -
Zhong Fan,
Schwabe Jeremia,
Thomann Ralf,
Mülhaupt Rolf
Publication year - 2019
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.201900015
Subject(s) - gibbsite , polyethylene , materials science , nanocomposite , catalysis , chemical engineering , molar mass , polymer chemistry , methylaluminoxane , pyridine , polymerization , chemistry , composite material , organic chemistry , polymer , metallocene , aluminium , engineering
Ultrathin single crystal γ‐Al(OH) 3 (Gibbsite) nanoplatelets with average thickness <20 nm and length <800 nm, pretreated with trimethylaluminum (TMA), represent highly efficient activators and supports bis(imino)pyridine iron (II) (FeBIP) complex to produce high density polyethylene (HDPE) as well as gibbsite/HDPE nanocomposites in exceptionally high yields. Opposite to both methylaluminoxane (MAO)‐activated homogeneous FeBIP catalyst and heterogenous silica‐supported single site catalysts, no addition of MAO is required. At low TMA/Fe = 50 molar ratio, the superior catalyst activity (up to 6500 kg mol −1 h −1 bar −1 ) of FeBIP@TMA@Gibbsite is paralleled by controlled polyethylene particle growth without encountering reactor‐fouling problems typical for homogeneous catalysts. TMA@Gibbsite is compared with other AlR 3 @Gibbsite activators. The Al/Fe molar ratio governs catalyst activity as well as molar mass, molar mass distribution, and thermal properties of polyethylene. Moreover, hexagonal gibbsite nanoplatelets are uniformly dispersed in polyethylene to yield agglomerate‐free polyethylene/gibbsite nanocomposites.