Ethylene/10-undecenoic acid copolymers prepared with different metallocene catalysts

Abstract

The synthesis and characterisation of several functionalised polyethylenes, obtained by direct copolymerisation of ethylene with 10-undecenoic acid (UA), have been carried out. Two metallocene complexes of Cs symmetry with different bridges were used: a dimethylsilyl bridge complex Me 2Si(Cp)(Flu)ZrCl2 and a phenylidene bridge complex Ph 2C(Cp)(Flu)ZrCl2. For comparison, results obtained with the Cp2ZrCl2/MAO system are also reported. The copolymerisation activity depends strongly on the metallocene complex and on the added amount of the UA comonomer. High incorporation levels of up to 7.3 mol-% are achieved when using the phenylidene bridged catalyst presenting a rigid structure and a wide bite angle. The effect of comonomer content and catalyst geometry on the crystalline structure and mechanical behaviour of the different copolymers are comprehensively discussed. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.