In situ polymerization of polyimide‐based nanocomposites via covalent incorporation of functionalized graphene nanosheets for enhancing mechanical, thermal, and electrical properties

In this study, we report an effective method to fabricate high-performance polyimide (PI)-based nanocomposites using 3-aminopropyltriethoxysilane functionalized graphene oxide (APTSi-GO) as the reinforcing filler. APTSi-GO nanosheets exhibit good dispersibility and compatibility with the polymer matrix because of the strong interfacial covalent interactions. PI-based nanocomposites with different loadings of functionalized graphene nanosheets (FGNS) were prepared by in situ polymerization and thermal imidization. The mechanical performance, thermal stability, and electrical conductivity of the FGNS/PI nanocomposites are significantly improved compared with those of pure PI by adding only a small amount of FGNS. For example, a 79% improvement in the tensile strength and a 132% increase in the tensile modulus are achieved by adding 1.5 wt % FGNS. The electrical and thermal conductivities of 1.5 wt % FGNS/PI are 2.6 x 10(-3) S/m and 0.321 W/mK, respectively, which are approximate to 10(10) and two times higher than those of pure PI. Furthermore, the incorporation of graphene significantly improves the glass-transition temperature and thermal stability. The success of this approach provides a good rationale for developing multifunctional and high-performance PI-based composite materials. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42724.