Optimization of intrinsic self-healing silicone coatings by benzotriazole loaded mesoporous silica

Multifunctional intrinsic self-healing polymers (ISP) are gaining increasing attention these days, and many studies have been devoted to solving the conflict between achieving high mechanical polymer strength and active polymer chain diffusion. In this research, we developed an optimized self-healing composite coating by adding Benzotriazole (BTA) loaded nano silica (SiO2@BTA) to a dynamic cross-linked Polydimethylsiloxane (PDMS) network , which allows substantial and fast healing of the material integrity upon damage due to the hydrogen interaction between urea and BTA. BTA leaching tests demonstrated a longer release profile during the coating service life and corrosion tests in a 3.5 wt% NaCl aqueous solution indicated that the SiO2@BTA modified PDMS coating shows enhanced corrosion protection of carbon steel upon coating damage. Moreover, after addition of SiO2@BTA, the material failure strength increased from similar to 1.5 MPa to similar to 5.5 MPa, and the healing efficiency increased from similar to 59% to similar to 90% for 24 h healing at room temperature. Above all, this research provides an intrinsic self-healing coating design method to improve the mechanical strength and the self-healing ability of the ISP as well as enhancing the coatings corrosion protection ability.

Automated summary

This research developed an optimized self-healing composite coating by adding SiO2@BTA to a dynamic cross-linked PDMS network, which significantly improved the healing speed of the material integrity and enhanced the corrosion protection ability of the coating on carbon steel.