A Photosensitive Copolymer for UV-curable Electrodeposition Coatings

A series of photosensitive random copolymers (UPDHES) were prepared by introducing acrylate groups onto the side chain of the copolymer backbone of N, N-domethyl amimethyl methacrylate (DMAEMA), 2-hydroxypropyl acrylate (HEA), 2-ethylhexyl acrylate (EHA), and styrene (St) (PDHES). The molecular structure of UPDHES was characterized by FTIR, 1HNMR and GPC. The photopolymerization kinetics of UPDHES with different C=C content was investigated using real time FTIR in which it was found that the UPDHES system h...     

环氧丙烯酸酯紫外光固化涂料的研制

实验合成了涂料用紫外光固化环氧丙烯酸树脂,并对其固化时间、铅笔硬度、附着力、柔韧性、耐磨性能及耐化学品性进行测试.得到了预期的效果.     

Corrosion behaviors of zinc and Zn-Ni alloy compositionally modulated multilayer coatings

Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited from dual baths. The coated samples were evaluated in terms of surface appearance, surface and cross-sectional morphologies, as well as corrosion resistance. The results obtained from the salt spray test show that the zinc and Zn-Ni alloy CMM coatings are more corrosion-resistant than the monolithic coatings of zinc or Zn-Ni alloy alone with a similar thickness. The corrosion potential measurement and anodic polarisation tests were undertaken to examine the probable corrosion mechanisms of zinc and Zn-Ni alloy CMM coatings. Analysis on the micrographic features of zinc and Zn-Ni alloy CMM coatings after the corrosion test explains the probable reasons why the Zn-Ni/Zn CMM coatings have a better protective performance. Surface morphologies and compositional analysis of the remaining coating material of Zn-Ni alloy deposit after the corrosion test confirms the dezincification mechanism of the Zn-Ni alloy deposit during the corrosion process.     

Effects of magnetic fields on Fe-Si composite electrodeposition

Coatings containing Fe-Si particles were electrodeposited on 3.0wt% Si steel sheets under magnetic fields. The effects of magnetic flux density （MFD）, electrode arrangement and current density on the surface morphology, the silicon content in the coatings and the cathode current efficiency were investigated. When a magnetic field was applied parallel to the current and when the MFD was less than 0.5 T, numerous needle-like structures appeared on the coating surface. With increasing MFD, the needle-like structures weakened and were transformed into dome-shaped structures. Meanwhile, compared to results obtained in the absence of a magnetic field, the silicon content in the coatings significantly increased as the MFD was increased for all of the samples obtained using a vertical electrode system. However, in the case of an aclinic electrode system, the silicon content decreased. Furthermore, the cathode current efficiency was considerably diminished when a magnetic field was applied. A possible mechanism for these phenomena was discussed.     

金属锌电沉积的分形研究

以环形金属锌板作为阳极,石墨棒作为阴极,对电沉积过程中金属锌的二维枝晶生长进行了研究,并对不同电沉积条件下所得到的沉积产物的分形维数和宏观形貌进行了观察、分析.研究表明,随外加电压的升高,金属锌二维沉积产物的形貌由开放的枝状晶向致密的粗大枝晶转变,分形维数也呈增大趋势;随着电解质溶液中硫酸锌浓度的增加,阴极沉积产物先后出现了类似于DLA模型模拟结果的枝状形貌、具有分叉结构的致密纤维状枝晶簇和较为粗壮的开放型规则分叉状枝晶等不同形貌,分形维数亦随之发生相应的改变.     

Synthesis and properties of UV-curable hyperbranched polyurethane and its application in the negative-type photoresist

UV-curable hyperbranched polyurethane(UV-HBPU) containing carboxyl groups was synthesized from isophorone diisocyanate(IPDI), diethanolamine(DEOA), polyethylene glycol(PEG-400), hydroxyethyl acrylate(HEA), and 2,2-bis(hydroxymethyl) propionic acid(DMPA). The UV-HBPU was used as a negative-type photoresist for a printed circuit board(PCB). Fourier-transform infrared spectroscopy(FTIR) and proton nuclear magnetic resonance(1HNMR) spectroscopy of UV-HBPUs indicated that the synthesis was successful. Differential scanning calorimetry(DSC) and thermogravimetric analysis(TGA) showed that the thermal stability of the UV-HBPUs decreased as the HEA content increased. The polymer exhibited excellent photoresist properties, and the resolution of circuits based on this negative-type photoresist reached 10 μm.     

Synthesis of a novel UV-curable prepolymer polypropyleneglycol diglycidyl ether diacrylate

A novel UV-curable prepolymer polypropyleneglycol diglycidyl ether diacrylate （PPGGEA） was synthesized by utilizing polypropyleneglycol diglycidyl ether （PPGGE） and acrylic acid （AA） as starting materials, N, N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthetic conditions were in the following： the concentration of N, N-dimethylbenzylamine was 0.80 wt% of reactants, the concentration of p-hydroxyanisole was 0.3 wt% of reactants, the reaction temperature was 90-110 ~C, and the molar ratio of PPGGE to AA was 1：2.2. Meanwhile, 1-hydroxycyclohexyl phenyl ketone of a UV-cured initiator was added to the synthesized PPGGEA to prepare a kind of UV-cured coating. The mechanical properties of the UV-cured films were determined, giving 29.99 MPa of tensile strength, 834.27 MPa of the Young＇s modulus and 5.66% of elongation at tear.     

Synthesis of A Novel UV-curable Oligmer 1,4-cyclohexanedimethanol Glycidyl Ether Acrylate and Study on Its UV-curing Properties

A novel UV-curable oligmer 1,4-cyclohexanedimethanol glycidyl ether acrylate(CHDMGEA) was synthesized by utilizing 1,4-cyclohexanedimethanol glycidyl ether(CHDMGE) and acrylic acid(AA) as starting materials, triphenyl phosphine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthetic conditions were that the concentration of triphenyl phosphine was 0.90% of reactants by weight, the concentration of p-hydroxyanisole was 0.20% of reactants by weight, the reaction temperature was 90-100 ℃, and the molar ratio of CHDMGE to AA was 0.5:1.1. The experimental results show that CHDMGEA is a kind of good UV-curable oligmer. The impact resistance of the UV-cured films with CHDMGEA as oligmer to prepare UV-curing coating was superior to that of the UV-cured films with bisphenol A diglycidyl ether diacrylate(BPGEA) as oligmer to prepare UV-curing coating.     

铝合金上电沉积Ni-P-CNTs复合镀层及其摩擦性能研究

采用复合电沉积法在铝合金表面上制备了镍 磷 碳纳米管（Ni-P-CNTs）复合镀层,并用X射线衍射（XRD）和扫描电镜（SEM）对其进行了表征,分析了电流密度和镀液中碳纳米管的质量浓度对复合镀层形貌及其摩擦磨损性能的影响.当电流密度为3.0 A/dm2时可以得到表面光亮、平整的复合镀层,复合镀层中碳纳米管体积分数随着镀液中碳纳米管质量浓度的增加而增加.Ni-P-CNTs复合镀层比Ni-P镀层具有更高的硬度、耐磨性能和更低的摩擦系数.随着复合镀层中碳纳米管体积分数的增加,复合镀层的磨损量和摩擦系数逐渐降低.复合镀层摩擦性能的改善是由于碳纳米管具有优异的力学性能和良好的自润滑性能.     

Electrochemical behavior of different shelled microcapsule composite copper coatings

Copper/liquid microcapsule composite coatings with polyvinyl alcohol (PVA), gelatin or methyl cellulose (MC) as shell materials were prepared by electrodeposition. The influence of shell materials on the corrosion resistance of the composite coatings in 0.1 M H2SO4 was investigated by means of electrochemical techniques, scanning electron microscopy (SEM), and energy dispersion spectrometry (EDS). The results show that the participation of microcapsules can enhance the corrosion resistance of the composite ...     

Electrodeposition of Ni-Co-Fe2O3 composite coatings

Ni-Co-Fe₂O₃ composite coatings were electrodeposited using cetyltrimethylammonium bromide (CTAB)-modified Watt’s nickel bath with Fe₂O₃ particles dispersed in it. The effects of the plating parameters on the chemical composition, structural and morphological characteristics of the electrodeposited Ni-Co-Fe₂O₃ composite coatings were investigated by energy dispersive X-ray (EDS) spectroscopy, X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results reveal that Fe₂O₃ particles can be codeposited in the Ni-Co matrix. The codeposition of Fe₂O₃ particles with Ni-Co is favoured at high Fe₂O₃ particle concentration and medium stirring, and the deposition of Co is favoured at high concentration of CTAB. Moreover, the study of the textural perfection of the deposits reveals that the presence of particles leads to the worsening of the quality of the observed 〈220〉 preferred orientation. Composites with high concentration of embedded particles exhibit a preferred crystal orientation of 〈111〉. The more the embedded Fe₂O₃ particles in the metallic matrix, the smaller the sizes of the crystallite for the composite deposits.     

Influence of current density on nano-Al_2O_3/Ni+Co bionic gradient composite coatings by electrodeposition

Metal and nano-ceramic nanocomposite coatings were prepared on the gray cast iron surface by the electredeposition method. The Ni-Co was used as the metal matrix, and nano-Al2O3 was chosen as the second-phase particulates. To avoid poor inter-face bonding and stress distribution, the gradient structure of biology materials was found as the model and therefore the gradient composite coating was prepared. The morphology of the composite coatings was flatter and the microstructure was denser than that of pure Ni-Co coatings. The composite coatings were prepared by different current densities, and the 2-D and 3-D morphologies of the surface coatings were observed. The result indicated that the 2-D structure became rougher and the 3-D surface density of apices became less when the current density was increased. The content of nanoparticulates reached a maximum value at the current density particles caused dispersive strengthening and grain refining.     

Mechanical electrodeposition of bright nanocrystalline nickel

A new mechanical electrodeposition technology was proposed, and nanocrystalline nickel deposit with bright and smooth surface was prepared in the bath without any additive agents. Unlike traditional methods, the novel technology employed dynamical hard particles to continuously polish the cathode surface and disturb the nearby solution during electrodepositing. Experimental results showed that the polishing effect of hard particles can effectively prevent the hydrogen bubbles and impurities from adhering on the deposit surface and avoid the production of pits, pinholes and nodules. Furthermore, comparing with the deposit prepared by traditional methods, the one prepared by the novel technology was substantially refined with grain size ranging from 30 to 80 nm. Every diffraction peak’s intensity of the deposit was reduced, the preferential orientation degree of (200) decreased and those of (111) and (220) increased. The microhardness notably increased. The magnetic properties were also changed with decreased saturation magnetization and increased coercive force. It was also found that variation of current density and cathode rotational speed could affect the structure and properties of the nickel deposits prepared by this technology. Supported by the Natural Science Foundation of Jiangsu Province, China (Grant No. BK2004005)     

聚丙烯腈中空纤维膜超滤阳极电泳的研究

主要研究了铸膜液浓度、添加剂含量对制备超滤阳极电泳漆的聚丙烯腈中空纤滤膜性能的影响及超滤过程中操作压力，料液过度等工艺参数的选择．对该模做了长期起滤运行实验．研究结果表明聚丙烯腈中空纤堆超滤膜是一种性能优良的阳极电泳漆超滤膜．     

分散方式对Ni-Si_3N_4纳米复合电镀层显微组织和性能的影响

采用超声波分散加机械搅拌技术在纯铜板上制备了含有纳米Si3N4颗粒的镍基纳米复合镀层,研究了分散方式对复合镀层中纳米颗粒含量、复合镀层组织结构、显微硬度和磨损性能的影响。利用扫描电镜(SEM)和X-射线衍射仪(XRD)分析了镀层表面的显微组织及相结构,通过磨损实验机检测了复合镀层的耐磨性能。结果表明,采用超声波分散技术可获得组织细密、高显微硬度的纳米复合镀层,其显微硬度最高可达996 HV,耐磨性能较未经超声波分散处理的镀层有显著提高。     

电沉积法制备高孔率泡沫金属的电流密度控制

针对高孔率泡沫金属的电阻特性，通过电流密度随时间的变化转换为镀区内的位置分布，建立了稳恒状态下，带状高孔率泡沫金属与阳极平行电沉积的理论模型，进而推导出表观电流密度分布的表达式，并对电化学步骤控制的泡沫金属电沉积进行了设备优化设计，使得泡沫金属电沉积的电流密度控制在最佳范围，保证泡沫金属的质量。这一工作，为电沉积法制备高孔率泡沫金属的设备制造和在线控制提供了理论依据，具有实际应用价值。     

氨络合物体系中镍阴极电沉积的电化学行为

通过极化曲线测量，对氨络合物体系中镍阴极电沉积电化学行为进行研究，系统探讨了溶液中总镍离子浓度、氨水浓度、氯化铵浓度、阴离子及温度等工艺条件对镍阴极还原的影响。研究结果表明：镍放电电流随着总镍离子浓度的上升而上升，随氨水浓度的升高而降低；在1—4mol／L氯化铵浓度范围内，镍放电电流随其浓度的降低而升高，而当氯化铵浓度低于1mol／L时，镍放电电流出现下降的现象；氯盐氨络合物体系中镍阴极放电电流明显高于硫酸盐氨络合物体系镍放电电流，镍放电电流随温度的升高而升高。根据实验现象，进一步分析了镍阴极电沉积电化学行为变化的原因。     

Synthesis of a novel UV-curable prepolymer hexanediol diglycidyl ether diacrylate and its cured film tensile property

A novel UV-curable prepolymer hexanediol diglycidyl ether diacrylate (HDGEA) was synthesized by utilizing hexanediol diglycidyl ether (HDGE) and acrylic acid (AA) as starting materials, N, N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor. The optimal synthetic conditions were that the concentration of N, N-dimethylbenzylamine was 0.80 wt% of reactants, the concentration of p-hydroxyanisole was 0.3 wt% of reactants, the reaction temperature was 90-110 ℃, and the molar ratio of HDGE to AA was 1︰2.2. Meanwhile, 1-hydroxycyclohexyl phenyl ketone of a UV-curing initiator was added to the synthesized HDGEA to prepare a kind of UV-curing coating. The mechanical properties of the UV-cured films were determined, giving 31.87 MPa of tensile strength, 871.88 MPa of Young’s modulus and 6.77% of elongation at tear.     

Manufacturing microporous foam zinc materials with high porosity by electrodeposition

In order to get foam zinc materials of porous metal electrode, a novel method for preparing foam zinc was proposed, in which the polyurethane foam with diameter of 0.3 mm as substrate was processed by degreasing, roughening, activating, electroless plating and electrodeposition. The main factors affecting the process, such as ZnSO₄ content, temperature, pH value, current density, and electrodes distance, were investigated comprehensively. The optimal process conditions are 250 g/L ZnSO₄, 20 g/L Al₂(SO₄)₃, 40 g/L KAl(SO₄)₂, 30 g/L Na₂SO₄, pH=3.5, 4.0 cm of electrodes distance and 0.04 A/cm² current density at 30 °C. The result shows that adding ultrasonic on the process can elevate the deepening plating ability and current efficiency. Foam zinc material with a high porosity of 92.2% and a three-dimensional network structure can be fabricated by electrodeposition.