Polymers comprised of polyethylene and mono-olefins and methods of making the same

Abstract From the Canadian patent

Disclosed are polymer compositions comprised of copolymers of polyethylene with , mono-olefins that exhibit low levels of long chain branching as indicated by , the narrow , theological breadths combined with the high molecular weight (M w) values of the , polymers. These characteristics, among others are realized by methods of , preparing polymerization catalysts disclosed herein. These methods include treating chromium-based , catalysts, having an alumina support with sulfate to avoid sintering of the alumina. , Methods of calcining the alumina support are further disclosed as well as the catalyst , compositions, comprised of chromium and a sulfate-treated alumina support which …