Preparation of Polyethylene Nano-fibres Using Rod-like MCM-41/TiCl4/MgCl2/THF Bi-supported Ziegler-Natta Catalytic System

One of the known groups of mesoporous materials is MCM-41 that has beenextensively used as support for different types of catalysts. In the present work,rod-like MCM-41 was synthesized to support TiCl4/MgCl2/THF catalyst to formthe bi-supported rod-like-MCM-41/TiCl4/MgCl2/THF catalytic system. Then, ethylene polymerization was performed by this synthesized catalytic system under 8bar ethylene pressure. The formation of rod-like semi-crystalline mesoporous MCM-41with relatively high surface area (~972 m2/g) was confirmed by SEM, XRD, and BETstudies. FTIR spectroscopy was used to confirm the omission of the organic template and water from the synthesized MCM-41. Investigating the specific surfacearea of the prepared catalyst by BETanalysis showed that after loading the catalyst onMCM-41support, the surface area is reduced considerably and it is reached a value ofapproximately 486 m2/g. XRD, SEM, and DSC analyses revealed that the synthesizedPE samples contained nano-fibres as their main morphological units. SEM analysisshowed the formation of dense polyethylene fibres with nanometer sized diameters andlengths of about 1 to more than 20 micrometers. DSC analysis showed the high melting point of 144°C for the synthesized PE samples and their crystal structure wasassigned to be orthorhombic by XRD investigations. Finally a relatively high activity of11×104g PE/mol Ti.h was obtained for the catalytic system.