Using a novel side‐chain liquid crystalline polymer as the surfactant and dispersing agent of graphene oxide for the improvement of thermal and mechanical properties of epoxy nanocomposites

Abstract To efficiently disperse graphene oxide (GO) in composite materials and fully leverage its unique chemical and physical properties, the novel side‐chain liquid crystalline surfactant (SCLCS) has been synthesized. This SCLCS comprises a chiral mesogenic unit, a nematic mesogenic unit with a hydroxy group, and a nematic mesogenic unit with a cyano group, specifically designed to modify GO sheets. The chiral Mesogenic unit can join into the side‐chain liquid crystal polymer matrix, further to be compatible with the side‐chain liquid crystal. The nematic Mesogenic unit with a hydroxy group can react with the GO by chemical bonding (SCLCS‐g‐GO) to disperse the GO sheets in the polymer matrix. The nematic Mesogenic unit with a cyano group possesses the simple preparation process and stable structure, which provides stability for the overall structure. These components can be connected by a silicon oxygen backbone to endow the system with more stability. The structures and comprehensive properties of the compound SCLCS‐g‐GO and SCLCS‐g‐GO/epoxy nanocomposites were analyzed through a series of tests, including POM, TGA, DSC, SEM, XRD, and FTIR. Compared with the neat epoxy and 3 wt% GO/epoxy composites, the thermal properties of SCLCS‐g‐GO/epoxy nanocomposites possess obvious improvement. The mechanical property measures can confirm that epoxy nanocomposites with different SCLCS‐g‐GO containing demonstrate enhanced flexural strength, flexural modulus, and impact strength. Highlights SCLCS decreases van der Waals force between neighboring GO sheets. Incorporation of SCLCS induces GO to possess better dispersion in the polymer matrix. Excellent compatibility between epoxy matrix and the SCLCS‐g‐GO. Powerful interfacial interaction between the GO layers and polymer matrix. SCLCS‐g‐GO improves mechanical properties and thermal stability of nanocomposite.