Synthesis and optical properties of cycloolefin copolymers for plastic substrates

Cycloolefin copolymers comprise a new class of polymer materials showing properties, of high glass transition temperature, optical clarity, low shrinkage, low moisture absorption and low birefringence. There are several types of cyclic olefin copolymers based on different type of cyclic monomers and polymerization methods. In ethylene/norbornene (E/NB) copolymerization, iPr(Cp)(Flu)ZrCl₂ catalyst exhibited more activity than Cp ₂ZrCl₂ and rac-Et(Ind)₂ZrCl₂ catalysts. By the incorporation of Norbornene in copolymer, the glass transition temperature (Tg) of copolymer became higher. The Tg of copolymer increased up to 190°C. The transmission of copolymers was above 90% over 300 ∼ 900 nm. The RI of ethylene/tetracyclododecene (E/TCD) copolymer was higher than that of E/NB copolymer. The RI of E/NB copolymer could not changed increasing NB contents, however, the RI of E/TCD copolymer increased with increasing of TCD contents. The E/NB copolymer has very low birefringence and that film has very smooth surface.