Corrosion resistance of hybrid films applied on tin plate: Precursor solution acidified with nitric acid (pH=3)

Abstract

Siloxane – poly (methylmethacrylate)-based materials are system s formed by a silicon network, to which chains of poly (methylmethacrylate) are linked by covalent bonds or by physica l interactions. Their stability and adherence allow their appli cation on substrates like tin plate in order to increase the corrosion re sistance. The aim of this work is to coat tin plate with a hybr id film obtained from a sol consisting of alkoxide precursors: 3 - (trimethoxysi lylpropyl) methacrylate (TMSM) and poly (methyl methacrylate) P MMA. Effect of tetraethoxysilane (TEOS) addition was evaluated. Morp hology was evaluated by SEM and contact angle. Electrochemical behavior was evaluated by open circuit potential (OCP), potenti odynamic polarization and electrochemical impedance spectroscop y (EIS). Results showed that siloxane-PMMA film obtained with a higher a ddition of TEOS had higher thickness. However, intense densific ation caused by TEOS addition promoted crack formation, thereby compr omising the corrosion resistance.