Synthesis of refractive index tunable silazane networks for transparent glass fiber reinforced composite

Organic-inorganic hybrid polymers have recently attracted attention as matrix materials for transparent glass fiber-reinforced composites because of their optical and thermal properties. In this study, a transparent glass fiber-reinforced composite composed of organic-inorganic structures was prepared by hydrosilylation of polysilazanes. To obtain the transparent composite, the refractive index of the silazane matrix was controlled by phenyl groups. Fourier transform infrared spectroscopy was used to identify the chemical structure of the cross-linked polysilazanes. The transmittance of the composite was 89.36%, close to that of the silazane matrix. The 10% weight loss temperature of the matrix resin was determined as 531.9 °C. To observe the mechanical properties of the composite, a three-point bending test was performed. The flexural strength and the flexural modulus of the composite increased by 65% and 52% compared to those of the silazane matrix, respectively. These results suggest that polysilazanes can be utilized for transparent glass fiber-reinforced composites as alternatives to organic polymers.