Evaluation of thermal properties of SiO₂/polyurethane acrylate-epoxy acrylate as coating for fiber Bragg grating sensor

Compared with polyurethane acrylate (PUA)-epoxy acrylate (EA), the SiO₂/PUA-EA shows better thermal properties by thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC). The initial decomposition temperature is 143.8 ℃, and the most mass loss occur at 320 ℃ for SiO₂/PUA-EA, both of which are higher than those of pure resin. The SiO₂/PUA-EA can be used as coating for FBG monitoring for curing of composites accurately. The residual stress for hybrid materials is 128 kPa, lower than that reported previously. SEM shows that no delamination occurs between the SiO₂/PUA-EA and the core of optical fibers indicating their good binding.