Synthesizing ethylene/1-octene copolymer and its nanocomposites with graphene and carbon nanotubes using a Ziegler − Natta catalyst

• Published in: Journal of macromolecular science. Part A, Pure and applied chemistry Vol. 57; no. 11; pp. 761 - 768
• Main Authors: Assar, S., Zohuri, G. H., Ramezanian, N., Ahmadjo, S.
• Format: Journal Article
• Language: English
• Published: New York Taylor & Francis 01.11.2020; Marcel Dekker, Inc
• Subjects: Carbon; Catalysts; Chemical synthesis; Copolymerization; Copolymers; Crystal structure; Crystallinity; Ethylene; ethylene/1-octene copolymerization; Graphene; Melt temperature; Multi wall carbon nanotubes; Nanocomposites; Octenes; Optimization; Physical properties; Polymerization; Polymers; Thermal stability; Ziegler-Natta catalyst; Ziegler-Natta catalysts
• ISSN: 1060-1325; 1520-5738
• DOI: 10.1080/10601325.2020.1774389

Copolymerization of ethylene and 1-octene was carried out using a Ziegler-Natta catalyst and the optimization of copolymerization conditions was studied. The optimum polymerization activity was obtained at 60 °C and [Al]:[Ti] molar ratio of 143:1. It was observed that the increase in the comonomer ratio in the feedstock influenced the physical properties of the final copolymer obtained. The results showed a range of crystallinity (X c ) from 68.5% to 34.8% and a range of melting temperature (Tm) from 140 °C to 129 °C for the synthesized copolymers. The viscosity average molecular weight (M̅ v ) of the polymers decreased as the polymerization temperature increased, however, by increasing the monomer pressure, the M̅ v of the polymers and the catalyst activity increased. Polymer nanocomposites containing graphene and multi-walled carbon nanotubes with different particle sizes were prepared under the optimum copolymerization conditions. The addition of graphene and multi-walled carbon nanotubes decreased the activity of the catalyst. However, the thermal stability, and crystallinity of the polymers were found to be increased.