Facile synthesis of high refractive index thiophene‐containing polystyrenes

Abstract High refractive index polymer films have been extensively investigated because of their wide application potentials. We now designed thiophene‐containing polystyrene as colorless and transparent high‐refractive‐index thin film. The copolystyrenes were synthesized by general radical polymerization with controlled mole ratios 0 : 10, 1 : 9, 3 : 7, 5 : 5, 7 : 3, 9 : 1, 10 : 0 (styrene : p ‐bromostyrene), respectively. Next, the thiophene‐containing polystyrenes were synthesized by Suzuki‐Miyaura coupling reaction. The chemical structures of synthesized thiophene‐containing polystyrene in accordance with ratios were confirmed by using 1 H‐NMR, 13 C‐NMR, and FTIR. The effect of the thiophene units on refractive index according to copolymer ratios were confirmed by using prism coupler. The thiophene‐containing polystyrene showed improved refractive index ranging from 1.58 to 1.67 and birefringence in the range of 0.0001–0.0019. The thermal stability and thermal behaviors of thiophene‐containing polystyrene also can be confirmed by TGA and DSC. The polymers have high glass transition temperature in the range of 108°C–177°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012