铜离子氧化铝粉增强磷酸酯对铝颜料的缓蚀作用

为使铝粉颜料广泛应用在水性漆或墨中,必须提高其耐腐蚀性。铝粉表面的羟基是吸附缓蚀剂的有效基团,采用Cu2+氧化铝粉实现铝粉表面羟基化,以酚醚型磷酸酯(TXP-10)作为缓蚀剂,探讨了反应介质、CuSO4·5H2O和TXP-10的用量对缓蚀效果的影响。结果表明:在pH为6,异丙醇∶水=100∶15的反应介质中,40g铝粉在0.3g CuSO4·5H2O羟基化作用下,吸附4g TXP-10,可达到较好缓蚀效果。红外光谱和X射线衍射测定表明,铜离子氧化金属铝在铝粉表面形成勃姆石结构的氧化铝的水合物吸附TXP-10。     

铝—丙烯衍生物电聚合涂层的缓蚀性能的形貌机理研究

对比研究了丙烯酸（ＡＡ）,丙烯腈（ＡＮ）和丙烯酰胺（ＡＭ）三种水溶性丙烯衍生物在铝电极上电化学聚合形成涂层,测试了涂层的缓蚀性能,用ＳＥＭ,ＸＰＳ和ＦＴＩＲ技术确认了涂层的形貌结构,推测了其电化学聚合机理,结果表明,涂层在０．５ｍｏｌ／Ｌ盐酸中的缓蚀性能较差,涂层形貌结构分析表明,丙烯衍生物在铝表面的原位电聚合皆为阴极还原机理。     

铝-丙烯衍生物电聚合涂层的缓蚀性能和形貌机理研究

对比研究了丙烯酸(AA),丙烯腈(AN)和丙烯酰胺(AM)三种水溶性丙烯衍生物在铝电极上电化学聚合形成涂层,测试了涂层的缓蚀性能,用SEM,XPS和FTIR技术确证了涂层的形貌结构,推测了其电化学聚合机理.结果表明,涂层在0.5mol/L盐酸中的缓蚀性能较差.涂层形貌结构分析表明,丙烯衍生物在铝表面的原位电聚合皆为阴极还原机理.     

水性丙烯酸涂料的改性及其功能化应用研究进展

介绍了水性丙烯酸、环氧树脂、聚氨酯、有机硅、有机氟以及纳米粒子的优缺点,简述了环氧树脂改性水性丙烯酸、聚氨酯改性水性丙烯酸、有机硅改性水性丙烯酸、有机氟改性水性丙烯酸以及纳米粒子改性水性丙烯酸等的研究进展,指出了目前水性丙烯酸改性研究存在的问题和研究方向。水性丙烯酸树脂通过上述的改性手段可获得优异的综合性能,从而大大提高水性丙烯酸涂料的使用性能,扩大了水性丙烯酸涂料的应用范围。对水性丙烯酸涂料体系功能化应用进行了分类介绍,重点对水性丙烯酸在防水涂料、防火涂料、防腐涂料、海洋防污涂料以及隔热保温涂料上的功能化应用进行介绍,指出水性丙烯酸涂料在功能化应用研究上的重、难点。最后提出了水性丙烯酸涂料将向着高性能、多功能的方向发展。     

多元氧化物和铝原位反应制备铝基复合材料的组织和性能

采用SEM、EDS、XRD、TEM和拉伸强度测试等研究Al2O3粒子增强的ZL109铝基复合材料。结果表明:多元氧化物和铝原位反应生成的Al2O3粒子尺寸细小,粒径约为0.1μm,在基体中弥散分布,与基体存在共格关系,(001)α(Al)//(010)α-Al2O3,[110]α(Al)//[001]α-Al2O3。原位反应中生成的金属间化合物经T6处理后,以Al5FeSi、FeCr、Mg2Si、Al3Ni、Al2Cu和Al7Cu4Ni相的形式存在于基体中,使得复合材料在300℃的拉伸强度达到163.4 MPa,较基体的提高7.9%。随Al2O3粒子含量的增加,25℃时,复合材料断口断裂方式由韧性断裂转变为解理断裂,再到穿晶断裂;而300℃时,断口断裂转变方式为脆性断裂到延性断裂。     

硅烷偶联剂改性的纳米二氧化硅包覆铝颜料的制备及其耐碱性能

在醇/水体系中,采用溶胶/凝胶法制备了硅烷偶联剂改性的纳米二氧化硅包覆的铝颜料,并采用SEM、FTIR等分析方法对包覆效果进行表征,检测了包覆产物的耐碱性,并对过程机理进行了分析。结果表明,硅烷偶联剂改性的二氧化硅可以在铝颜料表面形成一层包覆层,且硅烷偶联剂的含量越高,包覆层中颗粒物的含量越少,而有机膜的含量越高。硅烷偶联剂改性二氧化硅包覆铝颜料在pH值为11的碱性水溶液中,经720 h后,析出的氢气量为未包覆产品的2.7%,表明用此方法制备的铝颜料具有良好的耐碱性。硅烷偶联剂和二氧化硅并不是简单的混合,而是彼此缩合形成了均一的杂化材料。     

原位界面聚合法制备聚吡咯 / 棉织物导电复合材料

目的改进制备聚吡咯/棉织物导电复合材料的原位界面聚合方法。方法将改进的一步三相聚合方式与传统二步二相聚合方式进行分析对比,探讨吡咯浓度、氧化剂用量、水相浴比和油相浴比等制备条件对复合材料导电性能的影响,对产物进行形貌表征,并初步探讨三相界面聚合经历的主要过程。结果确定了较优聚合工艺条件:吡咯浓度0.2 mol/L,氧化剂/单体用量比为1.5,水相浴比为10 m L/g,油相浴比为30 m L/g,吐温-80质量浓度为2 g/L,反应温度为0℃,时间为2 h。该条件下,在棉织物表面获得了一层分布均匀且具有三维网状多孔结构形貌的导电聚吡咯膜。初步建立了反应模型:有机相中的表面活性剂胶束包裹吡咯单体,接近浸没于水相中的棉织物表面,在纤维吸附的Fe3+的引发作用下发生原位聚合。结论采用的水/纤维/油三相体系原位界面聚合方法具有耗时较短、操作简单、原料节省且适用于大面积制备等特点,可得到表面电阻在100~200Ω/sq的柔性导电复合材料。     

丙烯酸基水性金属防腐蚀涂料的研究与应用进展

金属的腐蚀防护有机涂层逐渐向更加环保的水性化发展趋势,改性丙烯酸基水性防腐蚀涂料具有耐腐蚀、耐老化、耐化学介质等特点,在防腐蚀涂料领域有着较为广泛的应用.从高分子链结构和引入新材料复合改性乳液两个角度较为系统地综述了水性丙烯酸树脂改性方法及机理,并简要介绍了改性水性丙烯酸防腐蚀涂料的应用进展.     

原位反应制备细颗粒TiB2增强铝基复合材料研究

热力学分析和试验结果证实，KBF4、Ti反应剂以一定的Ti／B原子比混合加入熔体，最终反应生成单一TiB2相，能抑制TiAl3等其它相的产生。在此基础上，分析比较了反应剂混合粉以预制块形式加入、气流载入熔体两工艺条件下的TiB2颗粒分布、大小。结果表明：通过氩气流载入反应混合粉，并快速搅拌熔体，可克服TiB2颗粒在晶界的团聚，细化颗粒，获得颗粒小于0．5um、且较均匀分布的TiB2／Al复合材料。     

甲基丙烯酸甲酯原位聚合包覆铜金粉

为了提高铜金粉的耐腐蚀性能,采用甲基丙烯酸甲酯(MMA)原位聚合对铜金粉进行了有机聚合物的包覆,以吸光度、光泽度与接枝率为主要评价指标,探讨单体用量、引发剂用量、偶联剂用量对原位聚合过程的影响,并采用IR、SEM和XRD等手段对包覆前后的铜金粉进行表征.结果表明:当m(MMA)/m(Cu)=0.2时,表面包覆PMMA后的铜金粉具有良好的耐腐蚀性能与光泽度;当m(AIBN)/m(MMA)=0.05时,耐腐蚀性能最佳,而此时的接枝率也达到最高点,即耐腐蚀性能与接枝率之间存在一定的对应关系;偶联剂MPS的加入有利于提高铜金粉的耐腐蚀性能,这是由于其分子结构中具有甲氧基(OCH3)与碳碳双键(C＝C),形成具有特殊功能的"分子桥"所致,从而将铜金粉与PMMA通过化学键牢固地结合起来.     

Surfactant inhibition of aluminium pigments for waterborne printing inks

Micrometre-sized aluminium particles are used as pigments in silver inks and for environmental reasons it is desirable to develop water-based formulations of such pigments. In waterborne coatings, however, aluminium is prone to react with water, with subsequent hydrogen gas evolution and loss of the silvery lustre. The protection against water of aluminium pigments by adsorption of either a nonionic or an anionic surfactant has been evaluated. Phosphate esters with different lengths of the hydrocarbon tail have been synthesised and tested, and were found to provide very effective protection of the pigments. Sodium dodecyl sulphate (SDS), on the other hand, was completely ineffective as inhibitor, even though the adsorption isotherm was about the same as for the structurally similar sodium dodecyl phosphate (SDP). This difference may be explained by formation of different types of complexes with the aluminium oxide surface. Outer-sphere complexes are suggested for SDS, whilst SDP can form more stable inner-sphere complexes. Tests with the non-surface active methyl phosphate as inhibiting agent gave insufficient protection, indicating that surface activity is crucial for the inhibition, and that the use of the phosphates as such is not enough to give proper protection. The work shows that amphiphilic compounds having phosphate as anchoring group are efficient in providing water resistance to aluminium pigments.     

Corrosion protection properties of new UV curable waterborne urethane acrylic coatings

Abstract

Looking to the development of sustainable and low impact chemical technologies, water based paints offer significant advantage especially for in field applications, where the problem of solvent emission is really stringent. Some water based coatings are represented by alkyd and epoxy paints, capable of cross-linking either by auto-oxidation or with polyamines. Polyurethane aqueous dispersions are finding wide acceptance due to their better durability, adhesion and mechanical properties. The research presented here describes the design, application and characterisation of well defined model structures of waterborne UV curing coatings. The waterborne resins used in this work are segmented anionomeric polyurethanes functionalised with acrylic end groups: they were prepared from polytetramethylene glycol, isophorone diisocyanate, dimethylol propionic acid, and hydroxyethylacrylate. The preliminary results concerning the corrosion protection properties of the new UV curable waterborne coatings applied onto metallic substrates are very promising and were obtained by using electrochemical techniques. Water uptake is the critical process determining the corrosion performance. In particular the necessity to formulate the coating starting from higher molecular weight polytetramethylene glycol for good barrier properties is evident from the electrochemical impedance spectroscopy data.     

Surface modification of PET films by atmospheric pressure plasma-induced acrylic acid inverse emulsion graft polymerization

In order to make polyester film surface hydrophilic, atmospheric pressure plasma jet (APPJ) is used to activate the film surface first followed by inverse emulsion grafting polymerization of acrylic acid (AA). The graft ratio and wettability test reveal that the effectiveness of APPJ on initiating graft polymerization increases with increasing plasma treatment duration and helium flow rate. As the jet-to-substrate distance increases, the graft efficiency goes through a maximum at 2 mm. When oxygen is added to the plasma treatment gas, the graft efficiency decreases substantially. Fourier transform infrared spectrometry (FTIR) analysis shows new bands appearing at 2500-3600 cm^− 1 and 1546 cm^− 1 for the plasma-grafted samples. Scanning electron microscopy (SEM) results show that the grafted layer is built with a large number of spherical particles at submicron or even nanoscale. With a high graft ratio, agglomeration of neighboring particles becomes more pronounced, and eventually a relatively continuous graft layer is obtained with a corresponding surface contact angle of 5° which is considered superhydrophilic.     

Corrosion protection of aluminum pigments by sol-gel coatings

New sol-gel coatings for the corrosion protection of aluminum pigments were developed. To this end, the pigment particles are first coated with a silica layer by phosphoric acid-catalyzed sol-gel processing of Si(OEt)₄, to which either hexadecyltrimethoxysilane or dimethyldimethoxysilane is condensed. The coated pigments have excellent anticorrosive properties in alkaline solutions as well as under boiling water conditions.     

原位生成铝基复合材料的激光焊接

采用大功率激光器研究新型铝基复合材料TiB2/ZL101的焊接性能,TiB2粒子的存在增加了焊缝熔池粘度降低了熔池流动性,影响了焊缝成形,增加了气孔敏感性.焊缝中气孔主要来源于氢和复合材料中的残留盐.激光焊接过程中较大的冷却速度使得焊缝晶粒非常细小,TiB2粒子在焊缝中分布更均匀,没有出现粒子偏析,主要是因为TiB2粒子是属于纳米级,在凝固过程中被凝固界面前沿所捕获而没有被推移.TiB2粒子没有与铝基体发生界面反应生成脆性相Al3Ti及AlB2,TiB2粒子与Al基体界面结合较好.结果表明,激光焊接后没有破坏TiB2粒子的增强效果.     

High dielectric constant polyaniline/poly(acrylic acid) composites prepared by in situ polymerization

An ultra-high dielectric constant composite of polyaniline, PANI–DBSA/PAA, was synthesized using in situ polymerization of aniline in an aqueous dispersion of poly-acrylic acid (PAA) in the presence of dodecylbenzene sulfonate (DBSA). The water-soluble PAA served as a polymeric stabilizer, protecting the PANI particles from macroscopic aggregation. A very high dielectric constant of ca. 2.0 × 10⁵ (at 1 kHz) was obtained for the composite containing 30% PANI by weight. The influence of the PANI content on the morphological, dielectric and electrical properties of the composites was investigated. The frequency dependence of dielectric permittivity, dielectric loss, loss tangent and electric modulus were analyzed in the frequency range from 0.5 kHz to 10 MHz. SEM micrograph revealed that composites with high PANI content (i.e., 20 wt%) consisted of numerous nano-scale PANI particles that were evenly distributed within the PAA matrix. The high dielectric constants of these composites were attributed to the sum of the small capacitors of the PANI particles.     

微弧氧化处理原位颗粒增强铝基复合材料的磨损性能(英文)

采用微弧氧化工艺来改善原位颗粒增强铝基复合材料的表面性能。通过向铝熔体中加入15%CuO来制备CuAl2增强铝基复合材料。所制备的材料经过热压、均匀化处理、淬火和人工时效处理,然后在含KOH、KF和Na2SiO3的电解液中进行微弧氧化处理。经微弧氧化处理,复合材料的表面生成了有效厚度约15μm的Al2O3膜层。洛氏硬度测试后,在压痕边缘部位没有出现裂纹或明显的剥离现象,表明Al2O3膜层与基底结合良好。干摩擦试验结果表明,Al2O3膜层对Al2O3球的破坏性作用具有明显的抑制,Al2O3膜层的磨损性能比基体提高15倍以上。     

Electrochemical polymerization of aniline on aluminum electrode from an oxalic acid and H2SO4 solutions

In this study, the polymerization of aniline on Al and Pt electrode was examined by cyclic voltammetry There had been reversible reaction on Al electrode. But on the other hand there had been irreversible reaction on Pt electrode. The addition of aniline into the solution led the decrease of current values. The current decreased by adsorption of anodic products on polymer surface. The fact that the anodic peak potential shifted to positive value shows that polyaniline (PANI) catalyzed the formation of polymer. This case shows that the aniline shifted the electrode potential to positive side by the adsorption on the surface. When Al electrode covered with polymer (in 50 mV s⁻¹ potential scanning rate after 20 cycles) was immersed into 1 N HCl solution, the inorganic layer decomposed on the metal surface. This led to decrease the polarization resistance of the metal. SEM microphotographs and EDX fingerprints also confirmed these results.     

SEM原位观察3104铝合金板材的断裂行为

利用原位拉伸扫描电镜,观察并研究了3104铝合金冷轧板动态拉伸过程中裂纹萌生和裂纹扩展情况,讨论了裂纹萌生和扩展与板材微观组织之间的关系。结果表明：在拉伸过程中,裂纹起源于滑移带处,并沿滑移带扩展。裂纹扩展路径受拉伸应力状态以及板材内部晶粒和粗大第二相分布的影响。原位拉伸断裂模式为韧窝断裂和剪切断裂复合断裂模式,断口形貌受裂纹扩展应力状态的影响。