Research of mesoporous silica loaded lignin to enhance the anti-corrosion and anti-weathering performance of epoxy surface.

A new type of filler was added to epoxy resin to prepare a composite coating with excellent corrosion and weathering resistance. The simple synthesis process and nonpolluting raw materials of this filler contribute to the development of green chemistry. Specifically, lignin was encapsulated in mesoporous silica, the synergistic effect between the two resulted in the formation of lignin/mesoporous silica composite particles (MSN-L) with excellent ultraviolet (UV) resistance. Moreover, MSN-L was incorporated into the epoxy coating to form an excellent barrier against the penetration of corrosive media. The coating was characterized using electrochemical impedance spectroscopy (EIS), contact angle analysis (WCA), confocal laser scanning microscopy (CLSM) and other testing methods. The results show that the epoxy coating doped with 2 wt% MSN-L exhibits good corrosion resistance and excellent surface stability before and after the accelerated aging experiments. The impedance value of the coating was 10 Ω•cm and the corrosion current was 10 mA/cm. After UV aging, the surface roughness was 71.3 % lower and the degree of reduction in the water contact angle was reduced by 61.2 % compared to the blank coating. This corrosion and weather-resistant coating significantly extends the service life of outdoor coatings and provides effective protection for metals used outdoors.