磷酸盐防锈颜料在水性涂料中的防腐蚀性能及作用机理

IMR OpenIR

	磷酸盐防锈颜料在水性涂料中的防腐蚀性能及作用机理
	胡妹
学位类型	硕士
导师	刘福春
	2012
学位授予单位	中国科学院金属研究所
学位授予地点	北京
学位专业	腐蚀科学与防护
关键词	水性涂料防锈颜料防腐蚀性能防腐蚀机理 Water-borne Coating Anti-corrosive Pigment Anticorrosion Property Anticorrosion Mechanism
摘要	"摘要金属材料的腐蚀不仅造成资源的浪费，更可能危及到重大工程、设施的安全。为了防止金属的腐蚀，人们研究了许多金属的防腐蚀方法，其中最有效最经济的方法是使用有机涂料对金属进行防护。以往有机涂料主要是溶剂型涂料，固然对金属有良好的防护作用，但在生产和施工过程中会挥发大量的有机溶剂，造成环境污染，危及人类健康安全。因而，研究一种环保、长效金属防腐涂料是涂料发展的必然趋势。近年来，水性涂料由于环保，且具有良好的防腐蚀作用获得了快速发展。利用防锈颜料可以大幅度提高水性涂料的防腐蚀性能。磷酸盐是一种重要的环境友好型防锈颜料，具有特别强的防腐蚀作用。目前，磷酸盐在水性涂层中的防腐蚀机理尚不完全明确，如是否可以通过磷酸盐防锈颜料表面有机改性提高其与树脂的相容性；磷酸盐防锈颜料是否具有pH值缓冲性，能降低涂层阴极区pH值，减缓阴极剥离速度；磷酸盐中的磷酸根离子与基材金属离子是否会发生络合作用沉积于涂层与基材界面。澄清磷酸盐防锈颜料的作用机理，对于设计、研制高性能水性防腐蚀涂料具有重要意义。本论文以聚丁二烯改性马来酸酐共聚物和脂肪酸改性聚酯聚氨酯分散体为成膜物质，选择正磷酸盐和多聚磷酸盐作为防锈颜料。正磷酸盐为有机改性的锌铝钼磷酸盐水合物（ZAM），有机改性的碱式正磷酸锌水合物（ZPO）；多聚磷酸盐为锶铝多磷酸盐水合物（SAPP），改性锶铝多磷酸盐水合物（SRPP）。对水性涂料的防腐蚀性能和防锈颜料的作用机理进行了系统的研究。通过盐雾试验和电化学阻抗谱试验研究了ZAM、ZPO、SAPP、SRPP四种防锈颜料在马来酸酐共聚物涂层和聚酯聚氨酯涂层中的防腐蚀性能。结果表明：防锈颜料能显著提高涂层的防腐蚀性能，ZAM和ZPO防锈颜料的防腐蚀效果优于SAPP和SRPP防锈颜料；研制了以聚酯聚氨酯涂料为底漆，双组分聚氨酯为面漆的配套体系。盐雾试验和电化学阻抗谱结果表明配套涂层具有优异的防腐蚀性能。通过SEM、EDX、XRD、XPS等测试探讨了颜料防腐蚀机理，四种磷酸盐防锈颜料主要通过其pH值缓冲性和涂层与基材的界面上腐蚀产物的生成而发挥其防腐蚀作用。防锈颜料表现出pH值缓冲性，能降低基材金属阴极区pH值，减缓阴极剥离速度；涂层与基材界面有一层FeOOH和Fe2O3铁的氧化物膜层生成。ZAM涂层和ZPO涂层界面除有一层FeOOH和Fe2O3膜层生成，还有一层ZnO与OH-反应产物生成，铁的氧化物膜层和Zn的氢氧化物膜层均能阻挡电解质溶液与内部基材的接触，减缓基材腐蚀速度。由于ZAM颜料和ZPO颜料中ZnO与OH-的作用，使其防腐蚀效果比SAPP颜料和SRPP颜料更优。关键词：水性涂料，防锈颜料，防腐蚀性能，防腐蚀机理"
其他摘要	"ABSTRACT Corrosion of metal materials not only results in waste of resources, but also jeopardizes the safety of major projects and facilities. Plenty of methods to prevent the metal corrosion have been developed, and the most effective and economical method is the application of organic coatings. Formerly solvent-borne coatings are main category of organic coatings, which will emit quantities of organic solvent to cause environmental pollution and do harm to human safty in the process of their production and application. Therefore, studying a kind of environmentally friendly and long-term effective organic coatings for metal is an inevitable trend. In recent years, water-borne coatings have developed rapidly for their environmentally benignly characteristics and good corrosive resistance. The incorporation of anti-corrosive pigments can largely improve the anti-corrosive property of water-borne coatings. Phosphate-based pigments are a kind of important environmentally friendly anti-corrosive pigments for its excellent property. At present, the mechanism of phosphate-based pigments in waterborne coatings is not explicit. It is uncertain whether pigment compatibility with resin can be improved through pigment surface modification or not; whether phosphate-based pigments have the pH buffer capacity, reducing the pH value and slowing down the delamination reaction or not; whether can phosphate ions complex with metal ions and deposit on the substrate or not. The clarification of anticorrosion mechanisms of pigments has important significance to design and research the high-performance water-borne anticorrosion coatings. In this paper, polybutadiene-maleic anhydride copolymer and fatty acid modified polyester polyurethane were chosen as film forming materials. Orthophosphate and polyphosphate were chosen as anti-corrosive pigments. Orthophosphate is organic modification of zinc-aluminum-molybdenum phosphate hydrate (ZAM) and organic modification of alkali orthophosphate zinc hydrate; Polyphosphate is strontium aluminum polyphosphate hydrate and modified strontium-aluminum polyphosphate hydrate. The corrosion protection properties of water-borne coatings and the anticorrosion mechanisms of pigments were investigated. The corrosion protection properties of SAPP, SRPP, ZAM, ZPO in maleic anhydride copolymer and polyester polyurethane coatings were studied through salt spray tests and electrochemical impedance spectroscopy experiments. Results showed that the four anticorrosive pigments exhibited excellent anticorrosive properties, and the anti- corrosive properties of coatings containing ZAM or ZPO is superior to that of coatings containing SAPP or SRPP; The polyester polyurethane primer fitted with the two-component polyurethane topcoat exhibited excellent properties in salt spray tests and electrochemical impedance spectroscopy experiments. The anticorrosion mechanisms of anticorrosive pigments were studied through SEM, EDX, XRD, XPS tests. Four kinds of phosphate-based anti-corrosive pigments exhibited anticorrosion resistance for their pH buffer properties and the formation of corrosion products on the substrate. Anti-corrosive pigments showed pH buffer properties, reducing the pH value of cathodic area and abating the delamination reaction; a layer composed of FeOOH and Fe2O3 formed on the interface between the coating and the substrate. A layer of FeOOH and Fe2O3 as well as a product generated by with ZnO and OH- were detected in the interface in the ZAM coating and the ZPO coating, the iron oxide and Zn hydroxide can give prevention to entrance of electrolyte solution into the substrate, decreasing its corrosion speed. ZAM and ZPO pigments showed supper inhibitive properties compared to SAPP and SRPP pigments for the reaction between ZnO and OH-. Key words: Water-borne coating, anti-corrosive pigment, anticorrosion property, anticorrosion mechanism "
文献类型	学位论文
条目标识符	http://ir.imr.ac.cn/handle/321006/64519
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	胡妹. 磷酸盐防锈颜料在水性涂料中的防腐蚀性能及作用机理[D]. 北京. 中国科学院金属研究所,2012.