Intrinsic birefringence, Δn0, is a material constant for the orientational birefringence of polymers, and has been measured by many researchers with various methods. However, the reported values of the same polymer sometimes disagree among the researchers because determination of the orientation degree is somehow complicated. Alternatively, a new method using the modified stress-optical rule (MSOR) was proposed for Δn0 measurement. In this study, literature data of the Δn0 for various polymers are assessed and the reliability of Δn0 estimated via the MSOR is discussed.
- Yuki Okada
- Osamu Urakawa
- Tadashi Inoue