The in-situ synthesis of protective coatings on steel through a surface spontaneous polymerization process

This article reports a new method of forming protective coatings on metal surfaces. The process is very simple and environmentally friendly. Polymerization occurs spontaneously on the metal surface after the immersion of a cleaned metal substrate into a dominantly aqueous monomer solution. A layer of coating with uniform thickness is formed in situ. The coating thickness can be controlled from 1 to 50 μm. This article will describe the spontaneous polymerization process as it occurs specifically on steel and for a 4-carboxyphenyl maleimide—styrene monomer system. The polymerization propagation mechanism is free radical, and alternating copolymers are always obtained in this system, even with significant changes in the monomer feed composition. This could be attributed to the formation of a charge transfer complex between the monomer pair. The incorporation of the rigid imide ring into the copolymer backbone significantly improves the coating's thermal properties, and styrene enhances the electrical properties. These properties are relatively insensitive to the monomer feed composition, supporting the formation of alternating copolymer. The effects of several process variables have been evaluated, including solution pH, monomer concentration, solution temperature, and monomer feed composition. The proposed initiation mechanism involves the direct electrochemical reduction of the monomer by the steel surface to generate the initiating free radicals. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1667–1680, 1997     

Coating formation by spontaneous polymerization on aluminum: Various monomers

Spontaneous polymerization to give conformal, uniform coatings on metals has been expanded to a series of different monomers. The monomer 4‐fluoro maleimide, when copolymerized with styrene, a coupling agent, and a bis‐maleimide crosslinker, imparts very low dielectric constant (2.4) to the coating while retaining high temperature resistance. Diethyl fumarate, with the same comonomers, enhances ductility and provides an adjustable glass transition temperature. Addition of glycidyl acrylate to the monomer system provides reactivity of the coating to epoxy resins. Kinetic studies using these monomers were consistent with the free radical polymerization mechanism. The rate of reaction seemed limited by the diffusion of species to the reaction site. Extent of incorporation of the new monomers into the chain backbone was verified, and adhesion and corrosion resistance properties examined. The data illustrate the versatility of the conformal, chrome free spontaneous polymerization process. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 875–885, 2000     

Protective coatings on aluminum by spontaneous polymerization

A novel process to form protective polymer coatings on aluminum using spontaneous polymerization is described. When an aluminum sample is immersed in a partly aqueous monomer solution, polymerization proceeds rapidly on the metal surface, without the addition of initiator, at room temperature. The polymer coatings studied here were formed using styrene (St), N-phenyl maleimide (NPMI), 2-methacryloyloxy acetoacetate (MEA), and bis-maleimide (BMI), monomers, from solutions of different compositions. A possible mechanism for spontaneous initiation and propagation is proposed. The effects of process variables such as polymerization time, monomer concentration, and monomer ratios in feed on the coating thickness and properties are presented. The glass transition temperatures, adhesion strength to aluminum, thermal stability and corrosion resistance of these coatings are reported. The coatings obtained are up to 50 μm thick and conform to the shape of the substrate. They have excellent thermal stability, low dielectric constant, and show very good resistance to corrosion under the ASTM B-117 accelerated salt fog test. Other monomers and metals may also be used.     

Adhesive and anticorrosive properties of poly(vinylidene fluoride) powders blended with phosphonated copolymers on galvanized steel plates

Fluoropolymers with adhesive and anticorrosive properties were investigated by blending statistical phosphonated copolymers with poly(vinylidene fluoride) (PVDF). In a first part, methacrylic monomers bearing dialkyl phosphonate and phosphonic acid groups were synthesized. Dimethyl(2‐methacryloyloxyethyl)phosphonate was obtained by carrying out a one‐step methacrylation of a commercial phosphonated alcohol. Then, a chemical conversion of the dimethyl phosphonate group to phosphonic acid groups was accomplished by two routes, including on the one hand a trimethylhalosilane and on the other hand an inorganic halide as dealkylation reagents. The resulting monomers were analyzed by nuclear magnetic resonance (NMR) spectroscopy and results were discussed. In a second part, the phosphonated monomers were copolymerized with methyl methacrylate in the presence of 2,2'‐azobis(isobutyronitrile) (AIBN) to give statistical copolymers in high yields. In a third and last part, copolymers were introduced into PVDF as adhesion promoters and anticorrosion inhibitors. Good dry and wet adhesion properties onto galvanized steel plates were obtained with blends containing mainly phosphonic acid groups. Results of corrosion tests show that the phosphonic acid groups maintain some level of adhesion, thereby preventing the spread of corrosion. However, the number of acid groups and their neighbors influence the adhesive and anticorrosive properties of the PVDF coatings. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2277–2287, 2002     

环氧树脂防腐涂料的研究

利用丙烯酸、甲基丙烯酸甲酯、甲基丙烯酸丁酯与苯乙烯的共聚方法,合成一种新型水性防腐涂料。反应中加入环氧有机硅,使得这种涂料兼具有有机与无机涂料的高硬度、高耐磨、高附着力等优点。     

Polymeric coatings based on acrylic resin latexes from miniemulsion polymerization using hydrocarbon resins as osmotic agents

Waterborne acrylic resins with a solid content higher than 40 wt % were obtained by miniemulsion polymerization of methyl methacrylate, butyl acrylate, and acrylic acid using a hydrocarbon coumarone–indene resin (HCR) as osmotic agent. HCR is a cheap polymer widely used for coatings and pressure‐sensitive adhesives. The resin leads to a higher hydrophobicity for the acrylic latex film and acts as osmotic agent in miniemulsion polymerization preventing Ostwald ripening, leading to latexes with particle sizes, size distributions, and stability comparable to those obtained using n‐hexadecane as osmotic agent. However, the monomer conversion and molecular weight were lower, indicating the occurrence of a chain‐transfer reaction. Atomic force microscopy analysis demonstrated that a smooth film surface with phase‐separated morphology was formed when using HCR. Faster film hardness development was achieved with HCR comparing with hexadecane. Compared with market standard in a paint formulation, a similar performance was achieved. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40569.     

铜基表面陶瓷涂层的制备与耐蚀性能研究

以Al2O3、TiO2和ZnO为骨料,钠水玻璃为粘接剂,在纯铜表面用热化学反应法制备了陶瓷涂层。X射线分析发现,陶瓷涂层热固化后,涂层内产生了NiAl2O4、Al2SiO5等新相,它提高了涂层与基体的结合强度。腐蚀实验表明,封孔后陶瓷涂层的耐酸、耐碱、耐盐等性能分别比纯铜基体提高了3.9、12.3和6.3倍;极化曲线表明,陶瓷涂层有明显的钝化区,其抗电化学腐蚀能力增强,抗盐雾腐蚀性比基体提高了5.0倍。     

Adhesion characterization of protective organic coatings by electrochemical impedance spectroscopy

Adhesion is considered in many situations to be a very important property of organic coatings for corrosion protection and much scientific work is devoted both to the study of the mechanism involved in polymer-metal adhesion and to the ways of measuring this property. The large number of experimental methods in existence to obtain information on coating adhesion is an indication of both the scientific and the technological interests in this material science and engineering area, but it is also a consequence of the difficulty in measuring adhesion in a general sense. As a partial alternative to the traditional adhesion measurement approaches for organic coatings, the evaluation of adhesion by electrochemical techniques such as electrochemical impedance spectroscopy (EIS) is discussed for different examples. The influences on adhesion of different pretreatments or organic coatings are discussed, considering aluminium, galvanized steel, and stainless steel substrates, and we have shown that the information obtained by using an electrochemical approach can be used for adhesion evaluation, with particular attention to the monitoring of adhesion in an aqueous environment, which is the most detrimental for protective organic coatings.     

金属陶瓷涂层耐蚀性能研究

采用溶胶－凝胶浸渍提拉法在不锈钢、纯铜及铝合金基体上制备具有保护性的ＳｉＯ２、ＺｒＯ２、ＴｉＯ２、Ａｌ２Ｏ３及ＳｉＯ２－ＴｉＯ２陶瓷涂层,利用阳极极化曲线的、循环动电位极曲线、点蚀电位的测量以及三氯化铁和５％硫酸介质中的腐蚀试验研究了所得陶瓷涂层的耐蚀性。结果表明,这些陶瓷涂层能大幅芳提高金属基体在各种腐蚀介的耐蚀性。     

Waterborne long alkyl chain branched copolymers used as release coatings synthesized by mini-emulsion polymerization

Waterborne long alkyl chain branched copolymers with excellent release performance for pressure-sensitive adhesive were synthesized via mini-emulsion polymerization. Dynamic light scattering, video-based contact angle measurement and electronic stripping testing were employed to characterize and analyze the structure and release properties of the resultant copolymers. The results showed that ultrasonic amplitude of 50% and ultrasonic duration of 15 min were the optimum conditions for the preparation of a mini-emulsion containing long alkyl chain monomer stearyl methacrylate (SMA). The ultimate conversion of monomers declined with increasing SMA, while the hydrophobicity of the copolymers increased. Release strength testing illustrated that the optimum amount of SMA for release coating was 60%, taking the cost factor into account, and better release performance could be obtained by increasing the coating thickness.     

电流波形对AZ91D镁合金电镀铜的影响

通过SEM、中性盐雾试验和结合力试验,研究了3种电流波形(平滑直流、半波整流及全波整流)对AZ91D镁合金上镀铜的影响。实验表明,全波整流和半波整流的微观形貌比较相近,晶粒大小均匀,排列规则、紧密;而平滑直流铜镀层较全波和半波整流的沉积晶粒较大,晶粒间缝隙较宽,排列不够紧密。3种电流波形下所得铜镀层的耐蚀性及结合力均良好,其中全波整流所得镀层的性能最佳。     

封闭型异氰酸酯固化马来酸酐聚丁二烯水性涂料的研究

以马来酸酐化低分子聚丁二烯(MALPB)为原料,通过加入过氧化物和封闭型异氰酸酯Bayhydur BL5140双固化剂体系制备了耐腐蚀性能优异的水性涂料,研究了双固化剂体系中封端型异氰酸酯固化剂BL5140对水性涂料的固化过程和性能的影响。试验结果表明:涂层厚度为20μm;硬度为3H～4H;附着力为0～1级。BL5140的加入可大幅提高涂层的耐热性能;而且BL5140的加入可提高镀锌板、镁合金的自腐蚀电位而对金属表面起到很好的保护作用,盐雾试验也表明该涂料耐蚀性能突出。     

Interfacial behavior of polyimide/primer/copper system by preoxidation of the primer

The copolymers of vinyl imidazole (VI) and vinyl trimethoxy silane (VTS) were applied as the corrosion inhibitors and the adhesion promoters for the polyimide/copper system at elevated temperatures. The mol ratios of VI to VTS were 100 : 0, 70 : 30, 30 : 70, and 0 : 100. Preoxidation of the primer was performed to improve the reactivity of the primer on poly(amic acid). A peel test was performed to evaluate the adhesion strength of the polyimide/primer/copper system after heat treatment at 400°C in a nitrogen atmosphere. The effect of the preoxidation of the primer on corrosion protection and adhesion promotion were investigated by Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The adhesion strength of the polyimide/primer/copper system depended on not only the chemical interaction between polyimide and the preoxidized primer, but also the thermal stability of the primer. It showed the highest value when the mol ratio of VI to VTS was 30 : 70. The primer layer reduced or suppressed copper diffusion into the polyimide layer. The degree of corrosion protection by the primer was affected by its thermal stability and its reactivity on copper. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2518–2524, 2000     

氟碳涂层体系对混凝土防护效果的研究

通过附着力、耐碱性、耐盐雾、透气性和吸水率试验比较了溶剂型和水性氟碳涂层的防腐效果,研究表明:溶剂型和水性氟碳涂层均具有良好的附着力、耐碱性和耐盐雾性能,溶剂型氟碳涂层能够完全封闭混凝土的孔隙,水性氟碳涂层的吸水率较大。     

Synthesis and friction properties of copper/PMMA composites by soapless emulsion polymerization

Copper (Cu)‐doped polymethylmethacrylate (PMMA) composites were prepared by soapless emulsion polymerization. In this process, copper nanoparticles were modified by sodium oleate (SOA) and the surface property of Cu nanoparticles changed from hydrophilic to hydrophobic. The hydrophobic Cu nanoparticles could not only avoid the oxidation of Cu in air but also improve the compatibility between Cu nanoparticles and PMMA. The TEM micrographs revealed that Cu nanoparticles were encapsulated in PMMA polymer microspheres. In addition, the uniform Cu/PMMA composite microspheres could be synthesized in such a soapless emulsion polymerization process. It was worth mentioning that the friction property in oil was well improved when little nanocomposites were added into the base oil, which indicated that the composites can be widely used in lubricating oil. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

粘接剂对热化学反应陶瓷涂层结构与性能的影响

采用相同的陶瓷骨料(SiO2+Al)、添加剂(MgO+CrO3)和固化工艺,分别以磷酸铝和水玻璃为粘接剂,在Q235钢上制备陶瓷涂层,对其相成分、微观形貌、热震性能以及耐蚀性能进行了分析测试,讨论了粘接剂对涂层耐蚀性的影响。结果表明,尽管以磷酸铝为粘接剂的陶瓷涂层在固化过程中产生少量孔隙,但仍具有比以水玻璃为粘接剂的陶瓷涂层更优异的抗热震性能以及耐酸、碱、盐腐蚀性能。     

有机防护型阻锈剂对混凝土耐久性的影响

钢筋混凝土结构耐久性不足的问题日益严重,而导致该结果的主要原因是氯离子引起的钢筋锈蚀。在提高混凝土结构耐久性的措施中,钢筋阻锈剂因其施工简易、经济、高效等优点而得到了广泛的使用。钢筋阻锈剂的使用目的是保护钢筋防止锈蚀。目前研究和应用较多的多为醇胺类阻锈剂,该类阻锈剂分子结构有其一定的优势,同时也存在一些不足,其中大多具有单个N原子的吸附中心,形成阻挡层的链较短,因此其在钢筋表面形成的吸附膜不够完整和稳定。本文介绍了一种含氨基酮分子的新型有机防护型阻锈剂。该阻锈剂可以在钢筋表面形成完整而稳定的保护膜保护钢筋免受侵蚀,但是其得以应用的前提是与混凝土有较好的相容性,对混凝土耐久性无负面影响。为了研究该阻锈剂对混凝土耐久性的影响,在混凝土试块内掺入不同量的阻锈剂,对其分别进行力学试验、毛细吸水试验,氯离子渗透试验和快速碳化试验,从而评价该阻锈剂对混凝土力学性能、抗渗性能、抗侵蚀性能以及抗碳化性能的影响。研究表明,阻锈剂的应用略微提高了混凝土的抗压强度,改善了混凝土的抗渗性、抗氯离子侵蚀性和抗碳化性,从而混凝土的耐久性得到了一定程度的提高。     

Synthesis of block copolymers by radical polymerization of end-functional polystyrene

End-functional polystyrenes with an N,N-diethyldithiocarbamyl group were prepared by the photopolymerization of styrene with novel diethyldithiocarbamate derivatives as photoiniferters. Under ultraviolet light, the end-functional polymers could initiate a second monomer to polymerize and form block copolymers, such as polystyrene-b-poly(methyl methacrylate), polystyrene-b-poly(vinyl acetate), and polystyrene-b-poly(n-butyl acrylate). According to end group analysis and electron spin resonance (ESR) spectroscopy, AB-type block copolymers were produced. The glass transition temperature and thermal stability of the block copolymers were investigated by means of thermal analysis. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1169–1174, 1997     

海水及模拟海水介质中铜缓蚀剂缓蚀机理的研究进展

阐述海水及模拟海水介质中各种有机类铜缓蚀剂的国内外研究进展和对各种有机类铜缓蚀剂的缓蚀机理和协同作用机理,并展望铜缓蚀剂新的研究和发展方向.     

Effect of bath ionic strength on adhesion and tribological properties of pure nickel and Ni-based nanocomposite coatings

The effect of electrolytic chemical concentration on wear-resistance, corrosion-resistance, adhesion and wettability properties of pure nickel and nickel–alumina composite coatings has been investigated in this paper. Coatings were electroplated over steel substrates under constant pulse conditions using pulse electrodeposition technique. Corrosion-resistance results show that the anti-corrosion properties are increasing with medium concentration (MC) both for pure nickel and nickel–alumina composite coating. For anti-wear properties, the MC showed increasing trend in case of pure nickel coatings but decreased in nickel–alumina composite coatings. In composite coating, the higher and low concentrations of electrolyte showed the higher wear resistance properties. Furthermore, the influence of electrolyte concentration on changing surface morphologies, mechanical, wettability and adhesion properties have been investigated and reported here. Surface morphologies of the synthesized coatings were studied with scanning electron microscopy (SEM) and energy-dispersive spectroscopy. Coatings surface mapping and wear analyses were examined by using 3D white light interferometry.