Correlation of the Abbe Number, the Refractive Index, and Glass Transition Temperature to the Degree of Polymerization of Norbornane in Polycarbonate Polymers

Noriyuki Kato; Shinya Ikeda; Manabu Hirakawa; Hiroshi Ito

doi:10.3390/polym12112484

Correlation of the Abbe Number, the Refractive Index, and Glass Transition Temperature to the Degree of Polymerization of Norbornane in Polycarbonate Polymers

Polymers (Basel). 2020 Oct 26;12(11):2484. doi: 10.3390/polym12112484.

Authors

Noriyuki Kato^{1

2}, Shinya Ikeda¹, Manabu Hirakawa¹, Hiroshi Ito^{2

3}

Affiliations

¹ Mitsubishi Gas Chemical Company, 2-5-2 Marunouchi, Chiyoda-ku, Tokyo 100-8324, Japan.
² Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan.
³ Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan.

Abstract

The influences of the average degree of polymerization (D_p), which is derived from M_n and terminal end group, on optical and thermal properties of various refractive indexed transparent polymers were investigated. In this study, we selected the alicyclic compound, Dinorbornane dimethanol (DNDM) homo polymer, because it has been used as a representative monomer in low refractive index polymers for its unique properties. DNDM monomer has a stable amorphous phase and reacts like a polymer. Its unique reaction allows continuous investigation from monomer to polymer. For hydroxy end group and phenolic end group polymers, the refractive index (n_d) decreased with increasing D_p, and both converged to same value in the high D_p region. However, the Abbe number (ν_d) of a hydroxy end group polymer is not dependent on D_p, and the ν_d of a phenolic end group polymer is greatly dependent on D_p. As for glass transition temperatures (T_g), both end group series were increased as D_p increased, and both converged to the same value.

Keywords: optical properties; polycarbonates; thermal properties.