Tea polyphenol radical scavenger loaded UV absorber for corrosion resistant and weathering resistant epoxy coating fabrication

In this study, a robust coating with enhanced corrosion resistant and weathering resistant properties was developed by incorporating novel UV resistant fillers into epoxy matrix. Tea polyphenol (TP) functioned as the free radical scavenger, which was encapsulated into mesoporous silica nanoparticles with UV absorption ability (MSN-TP) to obtain the UV resistant filler. With the incorporation of 2 wt% MSN-TP fillers in the epoxy matrix, the uniform distribution of MSN-TP nanoparticles could block the penetration of corrosive media and hence strengthening the barrier property of the coating. Moreover, the free radical scavenging ability of TP and the UV shielding effect of MSN functioned simultaneously to alleviate the weathering degradation of epoxy coating, which exhibited stabilized surface properties (including macro and micro morphology, FTIR, CLSM, gloss, and WCA) and good barrier performance during accelerated weathering exposure test. Such a robust EP/MSN-TP coating can considerably prolong the long-term protection during outdoor service life.