Preparation of novel hybrid polymeric coatings for corrosion protection of steel rebars

In this study, an organic–inorganic hybrid polymer for the corrosion protection of steel rebars was prepared from ethyl methacrylate, 3-(trimethoxysilyl)propyl methacrylate (TMPSM), through free-radical polymerisation using different molar ratios of benzoyl peroxide as the initiator. The samples were denoted as W1, W2, and W3. Following acidic hydrolysis and condensation of tetraethyl orthosilicate with the TMPSM using the sol-gel process, both solutions were then mixed to obtain a hybrid polymer matrix containing both organic and inorganic phases. Subsequently, steel reinforced coatings demonstrated the highest adhesion levels during adhesion tests. The hybrid polymer films were then characterised using Fourier transform infrared spectroscopy to confirm their skeletal structures. The structural features of the hybrid polymeric coatings were investigated using 1H and 13C NMR spectroscopy, and the overall impacts of structure on the thermal behaviour and thermal transformation were examined using thermogravimetric analysis and differential scanning calorimetry methods, while the surface and morphological characteristics of the corrosion product films were examined using SEM and AFM. The results showed that the coatings were similar in terms of surface topography, verifying their nanoscale distribution (18–200 nm particle size).