Effect of graphene oxide/layered double hydroxide modified by 7‐octenyltrimethoxysilane on the mechanical and gas barrier properties of fluoroelastomers

Abstract

AbstractLayered double hydroxide/graphene oxide (GLDH) composites (SGLDH) modified by 7‐octenyltrimethoxysilane (7‐OTOS) were prepared by co‐precipitation method. The structure and morphology of SGLDH were characterized using x‐ray diffraction, Fourier‐transform infrared spectroscopy (FTIR), x‐ray photoelectron spectroscopy, scanning electron microscopy (SEM), high‐resolution transmission electron microscopy, energy‐dispersive x‐ray spectroscopy, and thermogravimetric analysis. According to the obtained results, 7‐OTOS was successfully grafted onto graphene oxide (GO) and layered double hydroxide (LDH) surfaces. 7‐OTOS was grafted on both GO and LDH surfaces, which is why the amount of LDH loaded on the SGLDH surface was significantly increased compared with that on the GLDH composite. The filler‐matrix interfacial interactions of the SGLDH‐filled fluoroelastomer composites were characterized using contact angle analysis, dynamic mechanical analysis, RPA analysis, FTIR, SEM, and cross‐linking density tests. It was indicated that the interfacial interactions between the SGLDH and matrix were significantly improved, and the SGLDH was well dispersed in the fluoroelastomer composites. In addition, the gas barrier properties and mechanical properties of the fluoroelastomer composites were tested. The carbon dioxide permeability coefficients of the fluoroelastomer composites filled with 10‐phr SGLDH increased by about 32.1% and 20.3%, and the tensile strengths increased by about 47.6% and 27.7%, respectively, compared with those of the fluoroelastomer composites filled with 10‐phr LDH and GLDH.Highlights SLDH nanocomposites are based on silyl ether linkages to increase LDH loading. Elastomer nanocomposites exhibited interfacial cross‐linking mechanism. Interfacial interactions were exhibited between FKM and SGLDH. FKM/SGLDH exhibited enhanced gas barrier properties (+32%) compared to FKM. FKM/SGLDH exhibited enhanced mechanical properties (+47%) compared to FKM.