MgCl2·6CH3OH: A Simple Molecular Adduct and Its Influence As a Porous Support for Olefin Polymerization

A single phase molecular adduct, MgCl 2 ·6CH 3 OH has been synthesized using MgCl 2 and the simplest alcohol, methanol. Structural, spectroscopic, and morphological studies have been carried out for a better understanding of the single phase MgCl 2 ·6CH 3 OH adduct. 13 C CPMAS solid state NMR studies show all six methanol molecules are magnetically equivalent and present in a single environment around the Mg 2+ center. Raman spectral analysis of the characteristic peak at 708 cm –1 substantiates octahedral coordination of six CH 3 OH molecules around Mg 2+ . Solid state 13 C NMR measurements, made after heat treatment at different temperatures, have been utilized to understand the variations in CH 3 OH stoichiometry and coordination around Mg 2+ with temperature. A titanated active catalyst, TiCl 4 on MgCl 2 ·6CH 3 OH, has also been synthesized and subjected to detailed characterizations. The active catalyst shows high surface area (102 m 2 /g) and mesoporosity. The titanated catalyst has been screened for ethylene polymerization reactions using different cocatalysts (R 3 Al; R= −CH 3, −CH 2 CH 3, and −CH 2 CH(CH 3 ) 2 ). A total of 7.25 kg of polyethylene per gram of catalyst has been obtained with Me 3 Al cocatalyst, which is six times higher in activity compared with commercial Me 3 Al/TiCl 4 / MgCl 2 ·6EtOH-supported catalyst. Although porosity influences the catalytic activity, other factors also seem to contribute to the total catalytic activity.