A new post-metallocene catalyst for alkene polymerization: copolymerization of ethylene and 1-hexene with titanium complexes bearing N,N-dialkylcarbamato ligands

A new type of post-metallocene polymerization catalyst based on titanium complexes with N,N-dialkylcarbamato ligands was used to copolymerize ethylene and 1-hexene. These easy-to-synthesize and stable complexes in combination with different organoaluminium co-catalysts produce random ethylene/1-hexene copolymers characterized by a broad molecular weight distribution and high 1-hexene incorporation, as confirmed by SEC, DSC and 13C NMR analysis. The influence of the main reaction parameters on the polymerization reactions was studied including the type of catalyst components, solvent, temperature, the ethylene partial pressure and the [Al]/[Ti] ratio in the catalyst. A higher activity and a higher 1-hexene incorporation were achieved with AlMe3-depleted methylalumoxane as co-catalyst and chlorobenzene as solvent