Synthesis of cyclic olefin polymers with high glass transition temperature and high transparency using tungsten-based catalyst system

Abstract

Novel cyclic olefin polymers (COPs) derived from bulky cyclic olefins, tricyclodipentadiene (TCPD) and tricyclo[6.4.0.19,12]-tridec-10-ene (TTE), with high glass transition temperature (Tg), excellent thermal stability, and high transparency, have been synthesized by ring-opening metathesis polymerization (ROMP) and subsequent hydrogenation. ROMP of TCPD and TTE was carried out successfully without gel formation using a WCl6/i-Bu3Al/Et-OH/hexene catalyst system at room temperature. By changing the TCPD/TTE molar ratio, the optimized catalyst component ratio for the polymerization varied. Chemical structures of the unsaturated and hydrogenated polymers were characterized by 1H NMR technique. Thermal properties of these newly synthesized polymers were determined using TGA and DSC measurements. The degradation temperatures (Td) were all above 420°C in N2, indicating that all these copolymers had excellent thermal stability. After hydrogenation, Tg of ROMP polymers was decreased by 30-60°C. The Tg of h-pTCPD reached as high as about 230°C. The light transmittances of these polymer films were also analyzed using UV-Vis absorption spectroscopy. A high light transmittance of up to 92% was found by UV-Vis absorption spectra for these polymer films.

Keywords

• Ring-opening metathesis polymerization
• cyclic olefin polymer
• norbornene derivatives
• tungsten
• glass transition temperature