A comparative investigation on different silane coupling agents modified sericite mica/polyimide composites prepared by in situ polymerization

Abstract

To make clear the effect and mechanism of sericite mica (SM) modified by silane coupling agents (SCA) on the morphology and properties of polyimide (PI) composites, the SM modified by different SCA including 3-aminopropyltriethoxysilane (KH550), 3-glycidoxypropyltrimethoxysilane (KH560) and 3-methacryloxypropyltrimethoxysilane (KH570), respectively, with equal grafting rate was prepared and used to prepare a series of PI/SM composites with the same SM content (5.0 wt%) by in situ polymerization. The effects of different SCA on the structure and properties of PI composites were studied by means of FT-IR, XRD, SEM, X-ray photoelectron spectroscopy, TGA, tensile and dielectric tests, and their influence mechanism was analyzed. The results showed two-phase interfacial adhesion between KH550-SM and PI matrix was the strongest. PI/KH550-SM composite exhibited the best excellent thermal and mechanical properties, the lowest dielectric constant and loss. The investigation would be of great value for improving the interfacial effects between SM and PI matrix and developing PI composites in relevant application areas.