Transparent antifouling coatings via nanoencapsulation of a biocide

Transparent coatings releasing an antifouling agent (AF) can be used to reduce the marine fouling of optical lenses. A variety of water‐borne coatings based on poly(methyl methacrylate‐co‐butyl acrylate) (PMMA‐co‐PBA) were synthesized using a two‐stage miniemulsion process. During this process, the AF, SeaNine 211, was nanoencapsulated in domains small enough not to scatter light. The release rate of SeaNine 211 was studied for the polymers of different T_g, and found to be sufficient to impart AF properties. However, over time, the coatings were found to develop a whitish aspect (blushing) due to water retrodiffusion. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

水性金属防腐涂料的发展及其应用

简要介绍了水性金属防腐蚀涂料的发展概况及其在工业涂装中的应用。     

与溶剂型面漆配套的高性能水性木器白底漆的开发与应用

采用PUD乳液搭配PAC乳液和简单的填料搭配体系,制备了一种可以替代溶剂型PU/UPE/NC底漆的高性能水性木器底漆.讨论了不同成膜物、填料和成膜助剂的种类和用量以及流变助剂对涂膜性能和涂装外观的影响,同时对涂膜性能进行了分析和测试.结果表明：该产品可以对密度板及其切割边实现良好的封闭和填充,涂膜具有高填充、快速打磨、优异的机械性能和耐化学介质性能,可以配合溶剂型PU或NC实色面漆产品使用,以其低价、环保的优势完全可以取代溶剂型产品在密度板涂装上的应用.     

Corrosion protective bi‐layered composites of polyaniline and poly(o‐anisidine) on low carbon steel

Bi‐layered composites of polyaniline (PANI) and poly(o‐anisidine) (POA) were investigated for corrosion protection of low carbon steel (LCS). In this work, homopolymers and bi‐layers of PANI and POA were electropolymerized on LCS from an aqueous salicylate solution by using cyclic voltammetry. These coatings were characterized by cyclic voltammetry, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Corrosion tests were carried out in aqueous 3% NaCl solution for LCS coated with PANI, POA, bi‐layered POA/PANI (POA on top of the PANI) or PANI/POA (PANI on top of the POA) composites using open circuit potential (OCP) measurements, potentiodynamic polarization technique, and electrochemical impedance spectroscopy (EIS). The single layer of PANI and POA protected the LCS in 3% NaCl for 8 and 16 h, respectively. The bi‐layered composite coatings provide effective protection to LCS for a longer time than a single layered PANI or POA coating. However, the corrosion protection offered to LCS depends on the deposition order of polymer layers in the composite. The PANI/POA composite provides better protection to LCS against corrosion than POA/PANI coating. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

埋地管线用重防腐涂料的技术发展

介绍了埋地管线用重防腐涂料的主要发展历程,对几种常用埋地管线用防腐材料进行了评价和对比,从中得出熔结环氧粉末涂料应用于埋地管线中的优势。     

溶质离子在镁合金微弧氧化膜形成过程中的作用

利用交流脉冲微弧氧化电源在NaF、NaCl和NaI三种电解液中对AZ31镁合金样品进行处理,采用SEM、XPD和XPS观察分析溶质离子对镁合金样品表面形貌、相组成及起弧前后微弧氧化膜层成分的变化。结果表明:微弧氧化现象只发生于NaF电解液中,起弧前样品表面的沉积膜为MgF2,起弧后膜层由MgF2和MgO两相组成;NaCl和NaI电解液中的两组样品既无微弧氧化现象发生,又未发现任何沉积膜层;微弧氧化初期阳极放电产生的金属阳离子与溶液中的阴离子形成沉积于样品表面的高阻抗膜层是微弧氧化过程进行的必要条件。     

The effects of thermosetting and castable encapsulation methods on the metallographic preparation of ceramic thermally sprayed coatings—A technical note

Accurate microstructural analysis of thermally sprayed coatings is possible only if specimen preparation produces a surface that clearly reveals the true microstructure. Comparison of similar specimens pre-pared by different laboratories, or different personnel in the same laboratory, often shows significant dif-ferences or variations in the microstructures, producing conflicting information that lowers the confi-dence level of microstructural analysis. A study was conducted on an alumina coating and an 8 wt% yttria-stabilized zirconia coating, both sprayed on metal substrates, to evaluate the effects of two differ-ent encapsulating procedures.     

Tensile strength of plasma-sprayed alumina and/or zirconia coatings on titanium

The heat treatment effect on the characteristics and tensile strength of plasma-sprayed alumina, yttria-stabilized zirconia (YSZ), and mixtures of alumina and YSZ coatings on titanium was investigated. The as-sprayed structures of alumina and YSZ coatings consists of a and y alumina phases, and cubic and tetragonal zirconia phases, respectively. The tensile strength of the coatings containing a large amount of YSZ is increased from 25 to 50 MPa by heat treatment at 800 °C. The 60% YSZ-AI₂O₃ coating showed the highest tensile strength. The tensile strength increase of the YSZ-containing coating by heat treatment is caused by formation of 10 to 100 nm wide microcracks. The interface adhesion strength between the heat-treated titanium substrate and the alumina-containing coating is increased by chemical reaction at the in-terface. Thus, a heat-treated alumina and zirconia mixture coating may be favorable in obtaining high tensile strength due to microcrack formation in the coating and the chemical reaction at the interface. During this work, S. Baba was a graduate student at Kyushu Institute of Technology, Sumitomo Metal Ind. Ltd., Osaka, Japan.     

Ti靶电流对CrTiAlN镀层组织结构及硬度的影响

利用磁控溅射技术在高速钢和单晶硅基体上沉积CrTiAlN梯度镀层,研究Ti靶电流对CrTiAlN镀层组织、相结构及硬度的影响.利用EDS、XRD和SEM分析镀层的成分、相结构及形貌,采用显微硬度计测量镀层的硬度.结果表明:随着Ti靶电流的增大,镀层中的Ti原子逐渐置换CrN中的Cr原子形成Cr-Ti-N体系,同时出现少量的TiN相;镀层生长的择优取向由(111)晶面逐渐转变为(200)晶面;镀层柱状晶的结构更为致密,其表面形貌由三棱锥结构逐步变为胞状结构;随Ti靶电流的增大,镀层硬度逐渐由1267HV升至1876HV.     

镁合金等离子喷涂Al/Al_2O_3涂层的耐腐蚀性能

采用等离子喷涂技术在AZ31镁合金表面制备Al/Al_2O_3复合涂层,测试了镁合金及表面喷涂有Al/Al_2O_3复合涂层的镁合金试样的极化曲线,研究了没有涂层、经封孔处理和未经封孔处理的喷涂有复合涂层的镁合金三种试样在浸泡腐蚀和5%NaCl盐雾腐蚀情况下的耐腐蚀性能及其腐蚀行为.结果表明,经封孔处理的Al/Al_2O_3复合涂层镁合金试样在上述腐蚀条件下的耐腐蚀性均优于镁合金和涂层未封孔处理的试样,在浸泡试验中未封孔处理的涂层试样比镁合金腐蚀更加严重,在盐雾试验中却优于镁合金.