A highly transparent and thermally stable copolymer of 1-adamantyl methacrylate and styrene

Thermal and optical properties of copolymers of 1-adamantyl methacrylate (AdMA) and styrene (St) are investigated. The azeotropic copolymer with a glass transition temperature of 170°C proves to be intrinsically more transparent than polystyrene. Thermal and optical properties of copolymers of 1-adamantyl methacrylate (AdMA) and styrene (St) prepared by free radical polymerization in the bulk are investigated. The copolymer forms an azeotrope when the composition is AdMA/St=55/45mol%. The glass transition temperature and decomposition temperature of the azeotropic copolymer are 170 and ca 340°C, respectively. The refractive index increases nonlinearly with St content from 1.522 to 1.591. The light scattering loss at 633nm is 28.1dBkm^-1, which is less than half of that of polystyrene. The total optical loss including molecular vibrational absorption, which is evaluated using a copolymer-based optical fiber, is 292-645dBkm^-1 at 500-700nm. These values correspond to transmittances of 86-93% for a 1m optical path length.