Structure and properties of epoxy-siloxane-silica nanocomposite coatings for corrosion protection.
Structure and properties of epoxy-siloxane-silica nanocomposite coatings for corrosion protection.
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DOI：
10.1016/j.jcis.2017.11.069
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发表时间：
2018-03
影响因子：
9.9
通讯作者：
R. F. Torrico;S. Harb;A. Trentin;M. C. Uvida;S. Pulcinelli;C. Santilli;P. Hammer
中科院分区：
文献类型：
--
作者：
R. F. Torrico;S. Harb;A. Trentin;M. C. Uvida;S. Pulcinelli;C. Santilli;P. Hammer
二氧化硅/硅氧烷相组成是决定环氧-硅氧烷-二氧化硅杂化涂料结构和性能的重要参数。通过仔细调整胶体前驱体配方，可以将纳米结构调整为高度凝聚和交联的杂化纳米复合材料，适合作为有效的防腐涂料。实验通过聚(双酚A-环氧氯丙烷)(DGEBA)与二乙三胺(DETA)和(3-缩水甘油氧丙基)甲基三乙氧基硅烷(GPTMS)的固化反应，然后由正硅氧基乙烷(TEOS)和GPTMS的水解缩合，制备了新型环氧硅氧烷-环氧氯丙烷-二氧化硅杂化材料。在有机相比例不变的情况下，研究了硅氧烷(GPTMS)和二氧化硅(TEOS)摩尔比的变化对薄膜性能的影响。详细的结构分析表明，对于TEOS/GPTMS的中间比例，高度凝聚的硅氧烷-硅氧烷结构域共价键合到嵌入的环氧相上。用原子力显微镜观察到，准球形、亚非对称硅氧烷结点的均匀分布与较低的表面粗糙度(<；5 nm)相一致。这种致密的纳米结构具有很高的热稳定性(>；300 °C)，与钢衬底的粘附性很强，在盐水溶液中具有优异的阻隔性能，耐腐蚀性在GΩ cm2范围内。
HypothesisThe 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.ExperimentsNovel epoxy-siloxane-silica hybrids have been prepared through the curing reaction of poly(bisphenol A-co-epichlorohydrin) (DGEBA) with diethyltriamine (DETA) and (3-glycidoxypropyl)methyltriethoxysilane (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.FindingsA 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 °C), strong adhesion to steel substrate and excellent barrier property in saline solution, with corrosion resistance in the GΩ cm2range.