Synthesis of Zero-Birefringence Polymers Based on Positive and Negative Birefringence Polymer
Birefringence of a polymer is caused by polymer chain orientation during an injection-molding, extrusion processing or heat drawing. Birefringence of polymers degrades the performance of optical devices that require focusing by lenses or maintaining the polarization state of incident light. Optical polymers which exhibit no birefringence with any orientation of polymer chains are desirable to realize high performance optical devices that handle polarized light. In this study we demonstrate the random copolymerization method for synthesizing the zero-birefringence polymers in which positive and negative birefringence homopolymer are blended. We synthesize a polymer that exhibits no orientational birefringence with any orientation degree in a system that is composed of Methyl methacrylate/Styrene/Benzyl methacrylate.
Yuan Ming Huang
W. J. Yang et al., "Synthesis of Zero-Birefringence Polymers Based on Positive and Negative Birefringence Polymer", Key Engineering Materials, Vols. 428-429, pp. 111-116, 2010