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Preparation of ultra high molecular weight amorphous poly(1‐hexene) by a Ziegler–Natta catalyst
Author(s) -
Ahmadjo Saeid
Publication year - 2016
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.3828
Subject(s) - polymerization , materials science , polymer , polymer chemistry , monomer , molar mass distribution , chemical engineering , catalysis , organic chemistry , composite material , chemistry , engineering
High molecular weight polymers such as poly (α‐olefin)s play a key role as drag‐reducing agents which are commonly used in pipeline industry. Heterogeneous Ziegler–Natta catalyst system of MgCl 2 .nEtOH/TiCl 4 /donor was prepared using a spherical MgCl 2 support and utilized in synthesis of poly(1‐hexene)s with a viscosity average molecular weight (M v ) up to 3.5 × 10 3 kDa. The influence of effective parameters including Al/Ti ratio, polymerization temperature, monomer concentration, effect of alkylaluminus type on the productivity, and molecular weight of the products was evaluated. It was suggested that the reactivity of the Al‐R group and the bulkiness of the cocatalyst were correlated to the performance of the Ziegler–Natta catalyst at different polymerization time and temperatures, affecting the catalyst activity and M v of polymers. Moreover, bulk polymerization method leads to higher viscosity average molecular weights, revealing the remarkable effect of polymerization method on the chain microstructure. Fourier transform infrared, 13 C Nuclear magnetic resonance spectra, and DSC thermogram of the prepared polymers confirmed the formation of poly(1‐hexene). The properties of the polymers measured by vortex test showed that these polymers could be used as a drag‐reducing agent. Drag‐reducing behaviors of the polymers exhibited a dependence on the M v of the obtained polymers that was changed by variation in polymerization parameters. Copyright © 2016 John Wiley & Sons, Ltd.