The role of PEG/glycerol ratio on the structure and corrosion protection properties of PU-silica coating

Autor(es)

Braz, Alvaro G. ; Pinto, Joao, V ; Pulcinelli, Sandra H. ; Santilli, Celso, V

• Tipo de documento: Artigo Científico
• Fonte: SURFACE & COATINGS TECHNOLOGY; v. 485, p. 10-pg., 2024-05-17.

Resumo

In this work, investigation was made of the effect of incorporation of polyethylene glycol (PEG) in glycerol-based PU-silica coatings, with the aim of enhance thermal, mechanical, and corrosion protection properties, and establish a comprehensive knowledge regarding the synthesis of novel hybrid PU coatings with variable PEG/ glycerol molar ratio. Nuclear magnetic resonance (13C 13 C NMR) and Fourier transform infrared (FTIR) spectroscopy analyses showed the conjugation of the PEG to the PU structure by urethane bonds, with the samples prepared using a higher amount of PEG presenting a less rigid structural conformation. Small-angle X-ray scattering (SAXS) measurements demonstrated a correlation between the inorganic fractal dimensionality and the PEG amount. The increasing PEG content contributes to improve thermal stability, coating roughness, and scratch hardness, that achieves typical values of 230 degrees C, 115 nm and 6H, respectively. As an anticorrosive barrier for steel, the 1.5 mu m thickness coating prepared with 75 % glycerol and 25 % PEG exhibits an impedance modulus exceeding 10 G Omega.cm2 Omega. cm 2 over 28 days in contact with saline solution. This new PEG/glycerol-based PU-silica coating proves highly suitable functional features for anticorrosive applications, offering commendable thermal stability, low thickness, high scratch resistance, and impressive impedance. (AU)

• Processo FAPESP: 23/09958-4 - Desenvolvimento de revestimentos híbridos multifuncionais sustentáveis GPU-SiO2/TiO2/ZrO2 para proteção da corrosão de estruturas metálicas
• Beneficiário: Álvaro Guimarães Braz
• Modalidade de apoio: Bolsas no Brasil - Programa Fixação de Jovens Doutores
• Processo FAPESP: 23/01616-7 - Desenvolvimento de revestimentos híbridos multifuncionais sustentáveis GPU-SiO2/TiO2/ZrO2 para proteção da corrosão de estruturas metálicas
• Beneficiário: Celso Valentim Santilli
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/50948-3 - INCT 2014: tecnologias ecoeficientes avançadas em produtos cimentícios
• Beneficiário: Vanderley Moacyr John
• Modalidade de apoio: Auxílio à Pesquisa - Temático