Comparison study on chelated and non-chelated titanate functionalized graphene nanosheets for enhancement of waterborne alkyd anticorrosion coating.

• The chemical structure of titanate affected its intercalation in graphene (RGO). • The hydrophilic chelated titanate (T) more effectively improved the dispersion of RGO. • T modified RGO can improve the initial impedance modulus and coating resistance. • Non-chelated titanate modified RGO favored the long-term anticorrosion property. • Building a balance between the dispersion and chemical resistance of RGO is crucial. Hydrophilic functionalization of reduced graphene (RGOs) is able to improve its dispersibility in aqueous polymer. However, the influence of hydrophilic segments on the chemical resistance of RGOs/polymer nanocomposites keeps indistinct. Here, we prepared RGOs functionalized with hydrophilic chelated titanate (TA) and non-chelated titanate (T), named as TARGOs and TRGOs, respectively. The intercalation reaction mechanism between titanate and GO was elucidated. The presence of hydrophilic triethanolamine in titanate had little impact on the structural disorder of RGOs, but can effectively improve the exfoliation degree and the dispersibility of functionalized RGOs in waterborne alkyd resin (WAAR). The water resistance and thermal stability of TARGOs/WAAR were inferior to that of TRGOs/WAAR. The initial impedance modulus and coating resistance of TARGOs/WAAR were higher than TRGOs/WAAR at the same RGOs content when the RGOs content is 0.5% owing to the more homogeneous distribution of TARGOs in WAAR. However, the corrosion resistance of TARGOs/WAAR significantly decreased when the TARGOs content increased to 0.7%, which can be attributed to the presence of hydrophilic regions. In contrast, TRGOs/WAAR displayed the optimum long-term corrosion resistance when the TRGOs content was 0.7%, even though the dispersion of TRGOs in WAAR cannot be comparable to TARGOs in WAAR. [ABSTRACT FROM AUTHOR]