Homopolymerization and copolymerization of tert-butyl methacrylate and norbornene with nickel-based methylaluminoxane catalysts

Abstract

The homopolymerization and copolymerization of tert-butyl methacrylate (tBMA) and norbornene (NB) with nickel(II) acetylacetonate in combination with methylaluminoxane were systematically investigated. This catalytic system showed high activity toward the homopolymerization of both NB and tBMA. For these copolymerizations, activity was gradually lost with an addition of tBMA to NB or of NB to tBMA. This result was qualitatively explained with the trigger coordination mechanism. Furthermore, the determination of the reactivity ratios indicated a significantly whigher reactivity for NB than for tBMA (r(NB) = 4.14 and r(tBMA) = 0.097), and this was interpreted by the coordination mechanism. The synthesized acrylate/NB copolymers exhibited glass-transition temperatures of 100-250degreesC. The absence of crystallinity and the homogeneous repartition of the monomer units along the main chain yielded products with high transparency and high stability. (C) 2004 Wiley Periodicals, Inc.