Structure and properties of epoxy-siloxane-silica nanocomposite coatings for corrosion protection

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:513

Article

Torrico, Ruben F. A. O.¹  Harb, Samarah V.¹  Trentin, Andressa¹  Uvida, Mayara C.¹  Pulcinelli, Sandra H.¹  Santilli, Celso V.¹  Hammer, Peter¹ 

[1] Sao Paulo State Univ UNESP, Inst Chem, BR-14800060 Araraquara, SP, Brazil

关键词: Sol-gel process;    Organic-inorganic hybrid;    Structural properties;    Multifunctional coatings;    Corrosion protection;   

DOI  :  10.1016/j.jcis.2017.11.069

来源: Elsevier

【 摘 要 】

Hypothesis: The fraction of the silica/siloxane phase is a crucial parameter, which determines the structure and thus the properties of epoxy-siloxane-silica hybrid coatings. A careful adjustment of the colloidal precursor formulation allows tuning the nanostructure towards a highly condensed and cross linked hybrid nanocomposite, suitable as an efficient anticorrosive coating. Experiments: Novel epoxy-siloxane-silica hybrids have been prepared through the curing reaction of poly (bisphenol A-co-epichlorohydrin) (DGEBA) with diethyltriamine (DETA) and (3-glycidoxypropyl)methyl triethoxysilane (GPTMS), followed by hydrolytic condensation of tetraethoxysilane (TEOS) and GPTMS. At a constant proportion of the organic phase, the effects of the varying molar proportions of siloxane (GPTMS) and silica (TEOS) on the film properties have been investigated. Findings: A detailed structural analysis suggests for intermediate TEOS to GPTMS ratios a structure of highly condensed silica-siloxane domains covalently bonded to the embedding epoxy phase. The homogeneous distribution of the quasi-spherical sub-nonmetric silica-siloxane nodes is in agreement with low surface roughness (<5 nm), observed by atomic force microscopy. This dense nanostructure results in high thermal stability (>300 degrees C), strong adhesion to steel substrate and excellent barrier property in saline solution, with corrosion resistance in the G Omega cm(2) range. (C) 2017 Elsevier Inc. All rights reserved.

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