Polyolefins have become ubiquitous and are large volume commodity materials. Of current
interest is the preparation of speciality polymers incorporating polyethylene (PE), which often requires polymer chain-end manipulation. Ethylene polymerization by a neodymium catalyst in conjunction with n-butyloctylmagnesium (BOMg) is based on a reversible chain-transfer between Nd (where PE chains grow) and Mg (where PE chains rest). Using a large BOMg/Nd ratio for ethylene polymerization leads to magnesium-bound PE chains (PE-Mg-PE). We showed PE-Mg-PE is a precursor to end functionalized PE (PE-X) the potential
applications of which include the design of macromolecular architectures based on PE. A
drawback of the polymerization system is the optimum operating temperature (80°C) which is
sufficient to produce only low molecular weight PE. This study aims to develop a
polymerization system in which reversible chain transfer occurs at a high operating
temperature. A catalyst system based on a dichloro-iron(II)-2,8-bis(imino)quinoline complex, [(BIQ)FeCl2], is a suitable candidate due to i) satisfactory polymerization behaviour above 100°C when activated by methylaluminoxane (MAO) and ii) the potential for chain transfer with ZnEt2, established previously with Fe based catalysts. [(BIQ)FeCl2]) was assessed for
ethylene polymerization in the absence and in presence of ZnEt2.
