【作者】 张锋；

【导师】 李效玉；

【作者基本信息】 北京化工大学 ， 材料学， 2007， 博士

【摘要】 本文采用正交试验的方法,对环氧富锌、环氧云铁、环氧铁红、环氧石墨、氯化橡胶、聚氨酯等多种新型涂料,进行了最佳配方的确定,并制备出相应的产品。在此基础之上,采用盐雾试验、盐水浸泡试验、AFM、表面显微观察以及电化学等测试方法,对其在海水中的性能、防腐蚀机理进行了深入研究。实验结果表明：1、在环氧富锌涂料的设计中,本文通过对锌粉含量、颗粒大小、环氧树脂及其固化剂进行了筛选,通过涂膜的柔韧性、冲击强度、附着力、耐盐雾性能、耐盐水性能的测试结果分析,进而确定了更加有效的环氧富锌涂料配方,防腐蚀性能大大提高。该配方具有以下优点：环氧富锌涂料形成互连的结构,锌粉互相连接形成一个导电层,从而在锌粉牺牲的同时保护钢铁不受腐蚀介质的破坏。同时固化剂种类对防护性能也起着重要的作用,因此,选择合适的固化剂是提高环氧富锌涂料性能的关键因素之一2、在环氧云铁防腐涂料的设计中,通过对云铁用量、形状尺寸的研究、固化剂的选择和筛选,提出了环氧云铁涂料新型配方。2041固化剂性能最好,T31稍差但也接近,651的机械性能好,但耐介质性能较差。云铁的粒径影响相应较小,但从趋势看,325目的粒径的综合性能较好。因此我们的主配方选择如下：环氧树脂E44,2041固化剂,云铁用量(20%-30%),云铁粒径(325目为主,适当添加400目的颗粒)。3、在环氧铁红防腐涂料的设计中,首先是基料筛选、固化剂筛选,然后再进行颜、填料筛选以及颜基比的确定等步骤,确定了配方的组成。该涂层的特点是为一连续致密的膜,形成有机胶粒和颜料粒子交互间隔排列的均匀三维网络。4、在环氧石墨防腐涂料的设计中,主要考察环氧树脂的种类、用量,固化剂的种类,片状石墨的细度和用量等几方面的因素,采用正交设计法进行了涂料配方的筛选工作。测试主要从涂料的粘度、附着力、耐蒸馏水性等方面进行考查。实验结果表明：综合性能最佳的配方组合为：E44环氧树脂+2041固化剂+325目石墨,并确定了最佳石墨的用量。5、氯化橡胶防腐涂料配方的设计,主要从基料的选择、复合筛选、颜基比的确定,最终确定了配方组成。该涂层体系已不仅仅只形成一层阻挡层,而是携带有许多各种功能的添加剂的综合载体,其中的耐蚀物质可以有效地阻止涂层下金属腐蚀的发生和发展,使涂料具有较好的防护性能。6、聚氨酯涂料是较新的品种,弥补了环氧类防腐涂料不耐紫外线老化,不能低温固化的缺陷,具有施工温度低、干性快、涂膜光泽高、涂膜耐紫外线老化性能好等优点,并且具有耐磨、耐油、耐酸碱、耐水及化学药品和施工范围广等多种优异的性能,是目前综合性能较好的涂料品种之一。该涂料配方除具有上述特性外,还由于成膜物质的性质以及使用的颜料、填料、各种助剂等多方面的因素,使防腐涂料具有物理和电化学的保护作用。7、带油涂装防腐涂料是为了适应低表而处理要求而研究开发的一种新型涂料,采用正交设计法,通过对树脂基料、特种颜填料、溶油性添加剂和溶油性固化剂的筛选,确定了能适应于含少量油污的表面进行涂装的涂料配方,基本解决了舰艇维修中无法进行彻底除油处理部位的防腐问题。该涂料与底材的结合力强,与防腐而漆的配套性好。8、为了研究涂层的防腐蚀机理,在室温敞开的条件下测定了环氧石墨,醇酸,聚氨酯,氯化橡胶等多种涂层材料,在盐水和盐雾中的交流阻抗图谱,并且进行了比较。结果表明：环氧石墨、聚氨酯,氯化橡胶图谱均呈现出单圆,醇酸的阻抗图谱呈现明显的双圆,这说明电解质溶液迅速渗透到涂层/基层引起原电池腐蚀反应。在静态海水中,环氧石墨涂层的涂层电阻最大,聚氨酯涂层次之,接下来是氯化橡胶涂层,而醇酸涂层的涂层电阻最小；在环氧类涂层(环氧富锌,环氧石墨,环氧铁红,环氧云铁,无溶剂环氧)中,无溶剂环氧比云铁涂层略小,接下来是环氧铁红涂层,而环氧富锌涂层电阻最小。红外光谱分析进一步证明：环氧结构的存在大大提高了涂层材料的耐腐蚀性能,酚类结构也有助于其耐蚀性能的提高,而醛类和叔醇类结构对材料的耐蚀性能有负面影响。9、涂层表面的显微形貌观察发现：醇酸涂层表面就有多处的微孔,能够导致电解质对涂层的迅速渗透,使得涂层的耐腐蚀性能迅速下降,这与阻抗的实验结果一致。从颜填料的角度来看,环氧石墨的颜填料分布比较均匀,团聚也并不严重,在水溶液中防腐蚀性能优良；而聚氨酯涂层的颜填料分布虽然也较为均匀,但团聚的现象较为严重；此外,颜填料的表面迁移会使得涂层的耐腐蚀性能下降,证实了环氧涂层材料的耐腐蚀性能好于其他材料的结论。原子力显微观察的结果也表明：颜填料的种类,形态,大小以及表面迁移现象都对涂层性能影响较大。醇酸涂层的表面最为粗糙,氯化橡胶和环氧云铁涂层表面较为平整,但是有泡状的凸起存在,这有可能是表面颜填料团聚及迁移至表面的结果。10、阻抗数据结果分析发现,在水溶液体系中,当测得的涂层电阻低于106Ω cm2时,涂层对水等腐蚀介质的阻挡能力已经很弱,并且在涂层/金属界面有可能发生电化学腐蚀反应,进一步加剧了涂层的破坏。不同种类的有机涂层的盐雾试验结果也证实这一结论。11、通过对涂层/金属腐蚀界面反应动力学过程的分析,分别提出了聚氨酯、环氧云铁及氯化橡胶、醇酸在海水中的腐蚀动力学模型。聚氨酯、环氧云铁及氯化橡胶在海水中的电化学阻抗谱特征均为单容抗半圆。该图谱表明腐蚀受电解质溶液穿过涂层的速度所控制,可用涂层电阻(即容抗半圆直径Rp)表征；而醇酸阻抗谱低频区没有出现代表扩散过程控制的Warburg阻抗,而是代表电化学反应过程的容抗弧,这表明,醇酸涂层下的金属的腐蚀是化学反应步骤为控制步骤。更多还原

【Abstract】 According orthogonal experiments, the optimum precent of several new coatings, including zinc-enrichment epoxy, micaceous ferric oxide epoxy, iron red epoxy, graphite epoxy, chlorinated rubber and polyurethane, were selected and the corresponding products were prepared. Subsequently the performance and antivorrosion mechanism of obtained coatings were studied in seawater through salt spray test, saline immersing test, AFM, surface microscopic observation and electrochemistry test. Several conclusions were performed in following:1. During designing zinc-enrichment epoxy coating, the optimum precent of zinc-enrichment epoxy coating wes decided and its anticorrosive performance was improved remarkably through the repeatedly filtering the zinc powder content、 particle diameter、the type of epoxy、curing agents and analyzing the flexibility、 impact strength、adhesion force、resistance of salt spray and salt solution. This precent of coating has one advantage:zinc-enrichment epoxy coating can form a crosslink structure and joint zinc powders formed a conductive layer, which protected steel from corrosion by losting of zinc layer. At the same time, the type of curing regents is also one important factor, so appropriate curing regent can improve the performance of zinc-enrichment epoxy coating remarkably.2. During designing micaceous ferric oxide epoxy coating, one new precent of coating was suggested by chosing optimal concent and size micaceous ferric oxide. Among several curing regents,2041is best and T31is better. The mechanical propery of651is very good even if its worse resident of media. The chosen precent of coating is:epoxy resin E44, curing regent2041,20%-30%of micaceous ferric oxide and its size requied.3. During designing iron red epoxy coating, the base material、curing regent、coating、 filler were filtered in order and the ratio of paint-base material, subsequently optimal precent of coating was decided. This coating is a continuous film with three dimensional network structure, which is composed of organic colloidal particle and the pigments particles.4. During designing graphite epoxy coating, several factors were investigated, which including the type and content of epoxy resin、the type of curing regents、size and content of flake graphite. Filtering of coatings were performed by investigating orthogonal design, and viscosity、adhesion force、the residence of distilled water. The experiment results show that optimal concent of coating is:epoxy resin E44+curing regent2041+325iterm graphite, and optimal concent was decided contemporary.5. Design of chlorinated rubber coating was decided by investigating some factors, which including the base material、curing regent and the ratio of coating-base material. This coating is not only one barrier, but one complex with different additive regents, of which anticorrosive component can block the development of metal corrosion under coating.6. Compared with the other anticorrosive coating, polyurethane is a new product, which remedies some disadvantages of epoxy coatings (such as bad resisdence of UV and only curing at high temperature. Polyurethane coating has many advantages, such as low construction temperature、fast drying、high lustre and good resistance of UV、oil、water、acid、base、organic regents and wearing, so it belongs to good synthetical function. Except for the above advantage, good film-forming property and used several additive reagents (such as coating et al) can also makes coating belong to physical and electrochemical protection.7. Oil-based anticorrosion coatings is explored for simple surface preparation. By orthogonal experiments, base materials、speccial additive reagents、oil-soluble additives and oil-soluble curing reagents were filted, subsequently one coating percent for surface with a little oil pollution was decided. This coating solves anticorrosive problem of some unwieldiness parts because of its strong adhesion force with base materials and good combintation with top coat for corrosion protection.8. For studying the anticorrosive mechanism of coatings, the electrochemical impedance spectroscopy (EIS) of alkyd polyurethane, chlorinated rubber etc. in brine and salt fog at room temperature condition were measured. The results show that epoxy graphite, polyurethane, chlorinated rubber coatings present single circle and alkyd coating presents visible double circles. Those illuminate that electrolyte solution penetrate rapidly to coating/metal interface and cause corrosive cell reaction. In non-flowing seawater coating resistance for epoxy graphite is most than other tested coatings; polyurethane coating is second; third is chlorinated rubber coating; alkyd coating’s resistance is smallest. Among of the epoxy coatings, including epoxy zinc, epoxy graphite, epoxy MIO and non-solvent epoxy coating, the non-solvent epoxy coating’s resistance is smaller than the epoxy MIO’s. Second is epoxy ferric oxide coating; the smallest resistance is epoxy zinc coating. Infrared spectroscopy analysis further proves that exist of epoxy structure greatly improves their anticorrosion performance of coatings, and hydroxybenzene structure also help to coating’s promote anticorrosion property. But, aldehyde and tertiary alcool structure are harm to protection performance of organic coatings.9、Alkyd coating on its surface has many holes by examination topography observation, which can promise to electrolyte transfer fast through the coating. This results in the protection capability of the coating drops sharply. This foundation is in accordance with EIS results obtained by our tests. From view of fillers in coatings, the fillers for epoxy graphite dispersing uniform and agglomerating lightly, the coating in solution takes on well anticorrosion properties. Although the fillers for polyurethane disperse uniform, the agglomeration effect is heavier than alkyd’s. Furthermore, the surface move of fillers in coatings will cause anticorrosion property of those coatings to drop, which approve the conclusion that protection capabilities of epoxy coatings are better than other coatings. AFM results also show that sort, shape, size and surface move phenomena all have large influence on coating performance. The surface of alkyd coating is most rough, while the surfaces of chlorinated rubber and epoxy MIO are very flat. However, there are many bubbles heaving on their surface, this maybe result from results of fillers agglomeration and move on coating’s surface.10、By analysis the impedance data results, it is showed that the barrier capability against water and other corrosive medium is already small when the tested coating resistance is lower than106Ωcm2, and it maybe take palace that electrochemical corrosion reaction under the coating/metal interface, which would cause coating damage faster and faster. The fog test results for the different kinds of coatings also confirm this conclusion.11、The corrosion mechanisms models of polyurethane, micacous ferric oxide epoxy, chlorinated rubber, alkyd in seawater were given by analyzing the interface reaction kinetics processes of coating/metal substrate. EIS of the Polyurethane, micacous iron oxide and chlorinated rubber in seawater show single capacitance half circles. These EIS indicate the processes of corrosion are controlled by transfer of electrolyte in solution and the coating resistance, namely diameter of the obtained capacitive semicircles in tests (Rp) can reflect the properties of the coating protection in seawater. But, the Warburg impedance which represents the diffusion process of corrosion doesn’t appear in the tested EIS of the alkyd coating, and the capacitive circle which represents electrochemical reaction are found yet. This shows that the corrosion process under the painted alkyd coating is controlled by electrochemical reaction.更多还原