Effect of diisodecyl adipate concentration in hybrid films applied to tinplate

Siloxane hybrid films are fragile and have low mechanical strength due to their vitreous material properties. Hence, a new formulation incorporating a plasticizer agent was developed in order to increase the layer thickness of a uniform and homogeneous hybrid film on tinplate, and to provide flexibility to the polymeric matrix. Tinplate sheets were coated with a hybrid film obtained from a sol-gel process, constituted by the addition of the following alkoxide precursors: 3-(trimethoxysilyl) propyl methacrylate and tetraethoxysilane with 0.01 mol L-1 cerium nitrate addition. The influence of the diisodecyl adipate plasticizer concentration was evaluated. The films were characterized by scanning electron microscopy, profilometry, open circuit potential monitoring, polarization curves and electrochemical impedance spectroscopy. The results showed that all films with diisodecyl adipate had higher electrochemical performance compared to uncoated tinplate. However, the film with the 2% plasticizer concentrations had the best performance in the electrochemical tests, although it had thinner layer.