Synthesis of carbazole‐substituted poly(dimethylsiloxane) and its improved refractive index

A series of substituted 9‐vinylcarbazole polysiloxane was synthesized followed by room temperature vulcanization to afford a crosslink network via trimethoxysilane crosslinker. Structural confirmation was made using FTIR, one and two‐dimensional ¹H‐ and ²⁹Si‐NMR spectroscopy. Quantitative estimation of the amount of substituted carbazole was made based on NMR data. These were related to the refractive index whose values were in the range of 1.4370–1.4625 at increasing carbazole content. These values are higher than uncrosslink series, attributable to the tightness of the systems. They displayed an improved thermo‐optic coefficient compared to linear unsubstituted polydimethylsiloxane (PDMS). The synergistic effect of substituted carbazole unit with the crosslink network of PDMS presents a viable choice of encapsulant for opto‐electronic devices. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41654.