Cyclic Olefin Terpolymers with High Refractive Index and High Optical Transparency

Yihua Zhao; Yixin Zhang; Lei Cui; Zhongbao Jian

doi:10.1021/acsmacrolett.3c00043

Cyclic Olefin Terpolymers with High Refractive Index and High Optical Transparency

ACS Macro Lett. 2023 Mar 21;12(3):395-400. doi: 10.1021/acsmacrolett.3c00043. Epub 2023 Mar 6.

Authors

Yihua Zhao^{1

2}, Yixin Zhang¹, Lei Cui¹, Zhongbao Jian^{1

2}

Affiliations

¹ State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
² University of Science and Technology of China, Hefei 230026, China.

PMID: 36877004
DOI: 10.1021/acsmacrolett.3c00043

Abstract

Cyclic olefin copolymer (COC) is one of the most promising optical materials; however, the brittle COC suffers from issues including a low refractive index. In this contribution, by the introduction of high refractive index comonomers including phenoxy substituted α-olefin (C₄OAr), p-tolylthio substituted α-olefin (C₄SAr) and carbazolyl substituted α-olefins (C₄NAr, C₃NAr, and C₂NAr), the zirconocene mediated terpolymerization of ethylene (E) and tetracyclododecene (TCD) produces the preferred E-TCD-C_nNAr (n = 2, 3, and 4) cyclic olefin terpolymers (COT) with tunable compositions (TCD: 11.5- 35.8 mol %, C_nNAr: 1.2-5.0 mol %), high molecular weights and high glass transition temperatures (up to 167 °C) in high catalytic activities. Compared to the E-TCD copolymer (COC) material, these COT materials show the comparable thermal decomposition temperature (T_d,5% = 437 °C), slightly higher strain at break value (up to 7.4%) and higher tensile strength (up to 60.5 MPa). In particular, these noncrystalline optical COT materials have significantly higher refractive indices of 1.550-1.569 and are more transparent (transmittance: 93-95%), relative to the COC materials, indicative of an excellent optical material.