Mechanical and Dielectric Properties of NiZn Ferrite Powders-CTBN Modified Epoxy Resin Coatings

In this study, the effects of carboxyl terminated butadiene-acrylonitrile liquid rubber (CTBN) addition on the mechanical and dielectric properties of NiZn ferrite powders-CTBN modified epoxy resin coatings were investigated. It was observed that the occurrence of the small, dispersed spherical CTBN domains in the epoxy resin resulted from the phase separation between epoxy and CTBN could enhance the toughness and dielectric constant at low frequency due to the increase in the phase boundary between ferrite powders and epoxy resin for the samples modified with proper CTBN. The addition of ferrite powders can effectively improve the thermal stability of epoxy resin.     

环氧树脂/氮化铝复合材料冲击性能的研究

通过钛酸酯偶联剂处理氮化铝(AlN)粉末,采用机械分散和超声波分散相结合的方法,制得环氧树脂/AlN复合材料。实验表明,钛酸酯偶联剂能有效地改善AlN粉末的表面性能,偶联剂质量分数为6%时,改性效果最好;AlN填料质量分数为10%￣20%时,复合材料的冲击韧性较好。冲击断口形貌分析表明,河流状裂纹越窄,数量和分支越多,扩展路径越长,冲击韧性越好,A l N填料改性效果也越好。     

Effect of silane as surface modifier and coupling agent on rheological and protective performance of epoxy/nano-glassflake coating systems

Epoxy resin nanocomposites suspended with nano-glassflakes (NGFs) are studied in the present work. A bi-functional silane, i.e., epoxy propoxy propyl tri-methoxy silane, was used as coupling agent and NGFs’ surface modifier. Fourier transformed infrared spectroscopy and thermogravimetry techniques confirmed the successful surface treatment of the NGFs. Rheological studies of the polymer composites were carried out by measuring complex viscosity and storage and loss modulus values. The rheological results revealed that the presence of silane either as coupling agent or as surface modifier could decrease the nanocomposite viscosity. It is indicated that reduced filler–filler interaction resulted in better dispersion of NGFs. It can be due to soft layer formation on nano-glassflakes by silane groups which prevents the agglomeration of NGFs and subsequently improves their dispersion quality. Storage and loss modulus investigations showed that an inter-connected network structure in the solution might be formed in the presence of silane, probably due to the interaction between the NGFs and the polymer resin phase. Electrochemical impedance spectroscopies were carried out to study the protective performance of epoxy/nano-glassflakes coatings. Although the electrochemical impedance results revealed that the incorporation of silane as coupling agent and surface modifier in the epoxy/NGF coating systems applied on carbon steel substrates could improve the protective performance, the superiority of the epoxy coating formulated with 0.5 wt% of modified NGF was obviously visible during immersion period.     

Designing of corrosion resistant epoxy coatings embedded with polypyrrole/SiO2 composite

Polypyrrole/SiO₂ composite was synthesized by chemical oxidative polymerization of pyrrole using FeCl₃. The synthesized polymer composite was loaded in epoxy resin to develop coatings for mild steel substrates using powder coating technique. SEM and TEM images reveal homogenous dispersion of SiO₂ particles in polypyrrole matrix. TGA analysis confirms good thermal stability of the polymer composite. Tafel polarization and electrochemical impedance spectroscopy (EIS) results exhibit remarkably high corrosion protection efficiency of epoxy coatings with polymer composite in 3.5% NaCl solution. Corrosion studies of coatings with an artificial defect reveal the passivation of defect by the polymer composite present in the epoxy coatings. Salt spray test results revealed superior corrosion resistance offered by the polymer composite.     

Preparation and characterization of thermally stable epoxy-titanate coatings

Epoxy-polyamide coatings are used to protect metallic substrates in corrosive atmosphere. Thermal stability of the coating can be improved by the addition of inorganic cross-linking agent. Epoxy resin is incorporated with small percentage of silicone resin and cured with two types of hardeners such as polyamide and butyl titanate. The physical properties, heat resistance properties and electrochemical impedance behaviour of these coatings on steel in 0.5 M NaCl solution have been studied. The result implies that the heat resistant character of the titanate-cured coating is increased from 260 to 370 °C. The impedance study has shown that the coating resistance exerted by both the systems is in the range of 10⁵ Ω cm² after 6 days of immersion in 0.5 M NaCl. FTIR and Raman spectroscopy analysis confirm the presence of titanate linkage in the cured polymer coating. Thermal stability data indicate that the epoxy silicone resin cured with titanate hardener possesses higher thermal stability than that cured by polyamide hardener.     

环氧粉末涂料用固化剂的研究进展

固化剂作为涂料的成膜物质之一,一直是国内外涂料行业研究的热点.重点介绍了近年来环氧粉末涂料用固化剂的研究情况,从双氰胺和改性双氰胺、二羧酸二酰肼、异氰酸酯类、咪唑类衍生物和咪唑啉、多元羧酸铵盐和环脒多元羧酸（酐）盐、酸酐加成物、酚类固化剂、酚醛树脂、聚酯树脂和丙烯酸树脂与环氧树脂的反应机理等做了详细阐述,并指出了环氧粉末涂料用固化剂研究的发展趋势.     

羟烷基酰胺体系低温固化超耐候粉末涂料用聚酯树脂的合成研究

为克服聚酯树脂的性能缺陷,进一步提升羟烷基酰胺体系超耐候粉末涂料的耐候性能,使用溶液聚合制备环氧基丙烯酸酯预聚物,通过研究丙烯酸预聚物环氧值、用量对改性聚酯性能的影响,考察酸解剂对聚酯性能的作用,采用酯化缩聚工艺设计并制备出适用于羟烷基酰胺（ Primid）体系低温固化超耐候粉末涂料的新型聚酯树脂。结果表明：合成的新型聚酯具有高反应活性, 160 ℃固化涂层可兼顾耐冲击性和流平效果,涂料同时具有优异的贮存稳定性和突出的超耐候性。     

环氧防腐涂料在甲醇贮罐中的应用研究

采用低粘度环氧树脂、活性稀释剂、流平剂、消泡剂、偶联剂、硅微粉、改性胺固化剂等制得了环氧防腐涂料并应用于甲醇贮罐,考察了环氧树脂固化物的耐腐蚀性能。结果表明:该环氧涂层固化物经甲醇25℃/30d浸泡,质量变化率小,实际应用效果良好。     

纯环氧型钢筋粉末涂料的研制

采用环氧当量在845~900之间的二步法双酚A型环氧树脂同酚类固化剂搭配作为成膜主体,研究了固化剂、固化促进剂及填料用量对涂层综合性能的影响,优化了配方,制得了性能优异的纯环氧型钢筋粉末涂料产品,可满足当前国内建筑行业用环氧树脂涂层钢筋的各项性能要求。     

The effect of coupling agent on the microwave properties of the melt‐spun iron/earth nanocomposites

The effects of silane coupling agent doping on the microstructure and microwave properties of melt‐spun Nd‐Fe‐Co alloys were investigated. All as‐milled powders, with or without silane coupling agent treatment, were characterized as flake‐like shape. However, it is found that with the addition of 0.25 mL coupling agent, the as‐milled Nd‐Fe‐Co powders can deagglomerate and become more uniform dispersion with smaller thickness. In contrast, the excessive addition of coupling agent led to somewhat higher thickness of the flakes and much more amount of coupling agent on the surface of powder. The electromagnetic properties show that the Reflection loss will arrive ?27.1 dB at 4.2 GHz, for the addition of 0.25 mL coupling agent powders. The probably reasons for this are discussed on the basis of the morphology of the powders, uniform dispersion and the physical coating between the polymer and coupling agent. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

绢云母改性及其对环氧涂料性能的影响

用硅烷偶联剂KH-570分别对绢云母进行表面改性,并将改性绢云母分别添加到环氧树脂涂料。用红外光谱(FT-IR)、接触角试验及扫描电镜等对改性效果进行表征。试验结果显示:偶联剂成功地包覆于绢云母表面。通过偶联剂包覆改性,使绢云母在环氧树脂涂料中的分散性得到提高,明显增加了其与环氧树脂涂料的相容性。交流阻抗(EIS)测试结果表明,改性后的绢云母的添加明显提高了涂料的防腐性能。     

钛酸钾晶须及硫酸钙晶须改性环氧树脂

应用硅烷及钛酸酯等偶联剂对钛酸钾晶须及硫酸钙晶须进行表面处理，考察晶须对环氧树脂力学性能、工艺性等的影响。研究表明，钛酸钾晶须经硅烷偶联剂处理后，能很好地改善复合材料的性能，硅烷的表面处理效果较钛酸酯的好。钛酸钾晶须添加到环氧树脂中后，材料的弯曲强度随晶须含量增大逐渐增大，在晶须含量为8％时达到最大值，之后性能稍有下降；材料的弯曲模量随晶须添加量的增加逐渐增大，冲击强度稍有降低。体系中添加硫酸钙晶须后，材料的性能也得到一定程度的提高。硫酸钙晶须对环氧树脂工艺性的影响较钛酸钾晶须小。SEM表明，晶须经合适的偶联剂表面改性后，与树脂基体的界面粘接得到有效改善。     

新型陶瓷改性环氧树脂涂料的制备及性能表征

本文用甘氨酸改性环氧树脂,制备了水性环氧乳液。所制得的水性环氧乳液与陶瓷粉混合,在固化剂的作用下,得到了环氧树脂陶瓷涂料。通过正交实验确定了该涂料的最佳配方为:环氧树脂20g,甘氨酸3.3g,聚乙二醇(10000)1.6g,陶瓷粉6g,环氧固化剂4.5g。经性能测试,该涂料具有较好的涂膜性能,涂层可在室温下固化,使用方便。     

有机涂层在纤维增强聚合物基复合材料中的应用

介绍了不同涂层在纤维增强聚合物基复合材料中的应用和新近研究成果,其中包括偶联剂类(硅烷偶联剂、金属偶联剂)涂层和聚合物涂层(环氧树脂类和非环氧聚合物类),并综述了各种涂层方法(溶液浸渍法、界面原位聚合法、等离子体聚合法和电聚合法)的特点和应用研究进展。     

偶联剂KH570在低表面能纳米防污涂料中的应用

以合成的有机氟改性丙烯酸树脂为主要成膜物质,加入硅烷偶联剂KH570,改变涂料的配方,制备了防污涂料,讨论了偶联剂的加入方式、加入量对涂料性能影响,分析了低表面能涂料的表面结构。结果表明,偶联剂在高速分散时加入效果最好,加入量为颜填料的2%时,可以在不影响涂料性能的同时提高颜填料的用量或者减少树脂的用量,增大涂料的附着力,涂膜的附着力达到最高的1级,涂膜与水滴的接触角为146°,用SEM观察涂膜表面形成了纳米-微米阶层结构。     

铝粉粉末涂料邦定工艺的研究

本工艺通过设计聚酯/环氧型粉末涂料配方,采用邦定包膜技术将涂料粉末粒子与铝粉牢固黏结,静电喷涂试验表明该粉末涂料高度接近电镀铬效果,可作为电镀铬的替代产品.其中铝粉与粉末粒子良好粘结,铝粉使用量可降低30％;采用静电喷涂时,对不同金属元器件粘附良好,200℃固化10分钟,其涂膜拥有类似铬电镀的高光泽度金属效果,且色泽均一.相比溶剂型涂料60 ％～65％的成膜率,该粉末涂料成膜率接近100％,且未附着于被喷涂物件的粉末可以全部回收再利用.现有的邦定包膜技术具有高效环保、低成本等特点.     

Enhanced coating properties of Ni‐La‐ferrites/epoxy resin nanocomposites

Coating properties of new Ni‐La‐ferrites/epoxy resin nanocomposites has been achieved using modified epoxy resin with Ni‐La‐ferrite nanoparticles in the form of NiLaFeO₄/epoxy nanocomposites using electrochemical impedance and sorption of water measurements. Simple solution method with ultrasonic assistance was used in the preparation of the new nanocomposites in situ while epoxy resin was prepared. The new materials were characterized by X‐ray diffraction analysis, thermogravimetric analysis, scanning electron microscopy, and electrochemical impedance spectroscopy. The nanocrystalline NiLaFeO₄ showed a good distribution and high compatibility forming strong interfacial adhesion within the epoxy matrix. Furthermore, it had ability to facilitate thermal degradation of the epoxy resin nanocomposite due to its catalytic effect. Temperatures at 10, 25, 50% weight loss and the normalized solid residue left at 500°C (NR500) were measured. The presence of nanocrystalline NiLaFeO₄ stabilized the char residue obtained at 500°C in the resulting composites. The Ni‐La‐ferrite nanoparticles decreased water sorption (WS) of the epoxy. The 5% and 10%‐ Ni‐La‐ferrites/epoxy nanocomposites showed least amount of WS among the epoxy composites. The 5 and 10% Ni‐La‐ferrite nanoparticles contents enhanced significantly the barrier behavior of the epoxy as coating of stainless steel. POLYM. COMPOS., 36:1875–1883, 2015. © 2014 Society of Plastics Engineers     

添加剂对尼龙6铁氧体粘结磁体磁性能影响

系统研究了偶联剂和润滑剂等添加剂对注射成型尼龙6铁氧体粘结磁体磁性能的影响。结果表明,用偶联剂对磁粉进行表面处理,能够很好地改善树脂与磁粉的相容性,提高磁粉在树脂中的分散性,其中当偶联剂用量为2％（质量分数,下同）时,磁性能最好,剩磁（Br）、矫顽力（HcB）、内禀矫顽力（HcJ）以及最大磁能积（BHmax）分别达到0．23T,176．3kA／m,283．8kA／m,10．4kJ／m^3;润滑荆的使用能有效改善体系的流动性,降低共混过程中对磁粉结构的破坏,改善磁体的磁性,当润精剂用量为1％时,HcJ增加了9．3％。     

改性纳米氧化锌对丙烯酸聚氨酯涂层防腐性能的影响

为了改善纳米ZnO在涂料中的分散性,以钛酸酯偶联剂对其进行改性。研究了丙烯酸聚氨酯清漆、含未改性纳米氧化锌的丙烯酸聚氨酯涂层和添加钛酸酯偶联剂改性后的纳米氧化锌的丙烯酸聚氨酯涂层的防腐蚀性能。结果表明,经过钛酸酯偶联剂改性的纳米ZnO其团聚现象明显消失,与涂料表现出良好的相容性,所得的复合涂层的抗渗透能力明显比清漆和含未改性纳米ZnO复合涂层强。改性纳米ZnO显著提高了丙烯酸聚氨酯涂料的防腐性能。     

固化剂对环氧玻璃鳞片涂层性能的影响

以双酚A环氧树脂(E20)为主要成膜物,层片状玻璃鳞片和云母氧化铁为主要填料,辅助以铝粉、氧化铁红颜料,以及各种助剂和溶剂,再分别加入固化剂脂肪族胺加成物、聚酰胺TY-650,制得高固体分厚浆型环氧玻璃鳞片涂料。通过常规的力学性能(涂层的硬度、耐冲击性、柔韧性、附着力等)和耐腐蚀性测试,对比了不同固化剂对环氧玻璃鳞片涂层性能的影响。研究结果表明,脂肪族胺加成物与环氧树脂交联固化的玻璃鳞片涂层的硬度、附着力以及交流阻抗值都较高,具有良好的综合性能,加入铝粉对基体可起到阴极保护作用。