Preparation of OMMT/EA hybrid coating with high temperature resistance for FBG sensors

Hybrid coating of epoxy acrylate(EA) and modified nano organic montmorillonite(OMMT) was prepared for optical fiber Bragg grating(FBG) sensors. Mechanical performance testing and heat performance testing were carried on the OMMT/EA hybrid coating. The results demonstrate that, the performance of OMMT/EA coating with 2% mass fraction of nano OMMT is the best. SEM photographs and XRD analysis show that thesingle-lamellar nano OMMT is even distribution in EA. The tensile property, adhesion force, pencil hardness and glass temperature of OMMT/EA coating can be improved by adding nano OMMT, while the linear thermal expansion coefficient is decreased. FBG sensors with OMMT/EA coating and EA were embedded in the composites which processed under certain temperature and pressure, respectively. Comparing two groups of data, the results show that the modified OMMT/EA coating could obviously decrease the hysteresis of FBG sensor signals.