Zero-birefringence polymers

H. Ohkita, A. Tagaya, Y. Koike, Preparation of a Zero-birefringence Polymer Doped with a Birefringent Crystal and Analysis of Its Characteristics, Macromolecules 2004, 37, 8342—8348. 

Iwasaki, S., Satoh, Z., Shafiee, H., Tagaya, A., and Koike, Y. (2012). Design and synthesis of zero-zero-birefringence polymers in a quatemaiy copolymerization system. Polymer. 53, 3287-3296. 

IWATA ETAL. Transparent Zero-Birefringence Polymers... 

The Tg, refractive indices (no) and Abbe numbers (vd) of zero-birefringence polymers are shown in Table IV. The zero-birefringence poly(MMA-co-3FMA) and poly(MMA-co-BzMA) have slightly lower Tg (the former 90.0 0, the latter 103.30) compared with PMMA, because the Tgs of P3FMA and PBzMA are 64 and 6lO, respectively. Furthermore, the Tg of zero-birefringence PMMA with dopant molecules was also decreased by plasticization. 

The Abbe number (vd) measures the extent of wavelength dispersion of the refractive index. Polymers possessing a high Abbe number, such as PMMA, show low refractive index dispersion and are useful for lens and other optical elements. As shown in Table IV, the Abbe number of the zero-birefringence polymers (poly(MMA-co-BzMA), PMMA-Stilbene, and PMMA-Tolan) having phenyl groups were lower than that of PMMA. The Abbe number of a polymer is represented as. 

Koike, Y, Yamazaki, K., Ohkita, H., and Tagaya, A. (2006). Zero-birefringence optical polymer by birefrlngent cr3rstal and analysis of the compensation mechanism, Macomol. Symp., 235,64-70. 

B. R. Hahn and J. H. Wendorfif Compensatioo method for zero birefringence in oriented polymers. Polymer 28 1619 (1983). 

This article builds upon an earlier review on the same subject by Porter and Johnson in 1966 (14), and on the recent treatise on viscoelasticity in polymers by Ferry (15). We have generally tried to maintain the same nomenclature as the latter. Recent reviews on the relation between the zero-shear viscosity and molecular structure (16), crosslinked networks (17), and flow birefringence (18) in this same journal cover portions of the subject. We have tried to minimise redundancy with these works while at the same time making the review reasonably self-contained. 

---