The copolymerization of ethylene with cyclic olefin monomers produces high Tg, optically clear, low moisture absorption, and low birefringence materials. The processing of cyclic olefin copolymers is rather difficult and the relation between the rheological properties and the chemical structure should be well established. The incorporation of polar monomers such as acrylates is sometimes employed to improve the adhesion properties. The surface characteristics with the inclusion of the polar monomers is also the area to be analyzed. The aim of this research is to evaluate structure-property relations of the recently commercialized cyclic olefin copolyemrs by the structure analysis, rheological measurement, surface characterization and property estimation.
A series of ethylene/norbornene copolymers were synthesized at different ethylene/norbornene feed mole ratios in the presence of zirconocenes catalyst. Norbornene sequences of the copolymers were assigned by $^13C$ NMR spectroscopy. Norbornene content in copolymer varied form 13% to 55%. The Tg of the copolymer increased with norbornene content and the size of cyclic comonomer strongly influenced in the Tg of cyclic olefin copolymers. The rheological property of the copolymer was measured using ARES rheometer and Capillary rheometer.