It has been shown that, in suitable reaction conditions, it is possible to obtain ultra high molecular weight polyethylene with a reduced number of entanglements directly from the synthesis. This material shows interesting technological properties in terms of improved solid-state processability. Nascent powders can be compressed into films and ultrastretched to give high modulus, high strength tapes. At high temperature, above the melting point, the "disentangled'' state will revert to the fully entangled, thermodynamically stable state. This change can be followed by suitable techniques. In this study, we have investigated the effect that a cocatalyst modification can have on the catalyst performance and ultimately on the material properties and processability. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 31: 193-204, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21265 Copyright © 2012 Wiley Periodicals, Inc.