导电纤维在屏蔽塑料中应用的研究进展

导电屏蔽塑料是防止静电危害、电磁波污染的一种有广泛前景的功能高分子材料。本文综述了碳纤维、碳纳米管、不锈钢纤维、钢纤维和各种镀金属纤维填充导电屏蔽塑料的国内外研究进展。     

黄铜纤维／PVC复合导电塑料研制

本文概述了用黄铜纤维填充聚氯乙烯树脂制造导电塑料的方法,并对影响其导电性的主要因素进行了讨论。指出填充导电材料的形态因子、表面化学处理、纤维含量、加工工艺条件是影响聚氯乙烯复合物导电塑料导电性的主要因素。并对影响其机械性能的纤维含量、纤维长径比和加工助剂等因素进行了讨论。     

碳系填充型导电塑料的研究进展

综述了碳系填充型导电塑料的优点、常用制备方法和炭黑、石墨、碳纤维、超导碳粉和碳纳米管等碳系填充型导电塑料的研究进展。高导电碳纤维和高性价比导电填料的开发、导电机理研究的加强及纳米导电填料的应用将是未来碳系填充型导电塑料的研究方向和开发重点。     

导电纤维在复合型导电塑料中的应用

就导电纤维对复合型导电塑料导电性的影响,导电纤维的种类及国内外研究进展进行了简要的概述。研究表明,导电纤维可以在低添加量下获得高导电性能,是一种具有广泛应用前景的导电塑料。     

结构型与复合型导电塑料研究进展

概述了导电塑料的重大发现,阐明了塑料的导电机理和导电渗滤阈值,分析了不同加工工艺、不同导电炭黑、不同聚合物体系对材料导电性能和力学性能的影响,介绍了纳米技术在导电聚合物中的应用,综述了国内外结构型与复合型导电塑料最新技术成果、应用领域和研究进展。     

导电纤维填充型导电塑料在电磁屏蔽中的应用研究进展

简要阐述了电磁屏蔽的途径和机理,并对导电纤维填充型导电塑料的研究进展作了简单的介绍。     

导电塑料缆性阳极研制

介绍导电塑料缆性阳极的制备及其性能，研究不同导电炭黑，加工助剂，其它助剂及其用量对阳极电缆导电塑料包覆层性能的影响。结果表明，柔性的导电塑料层具有良好的力学性能、耐化学药品性及导电性，能保护铜芯免受腐蚀并将电流传导至被保护物；所研制的导电塑料缆性阳极能满足外加电流阴极保护工程的需要。     

复合型导电塑料的发展

阐述了作为功能材料的导电塑料的发展、分类及各类复合型导电塑料的加工、性能和应用。     

导电塑料母料的试制

概述了用双螺杆挤出机试制导电塑料母料的工艺过程,并就成型温度、进料速度、停留时间等因素,对导电塑料母料导电性的影响进行了讨论。用黄铜纤维复合的导电塑料母料的体积电阻率可达到20×10~(-3)Ω·cm。     

导电塑料在电子领域中的应用

近年来,有关导电塑料的研究受到了普遍的重视,研制和发展高效、低成本、易加工的新型导电塑料已成为电子领域的重要科研方向。本文介绍了电子行业用导电塑料的组成,讨论了导电塑料的导电机理、影响导电的因素,综述了该材料在电子领域的应用及研究进展,并提出了未来发展的方向。     

电磁屏蔽复合材料包装箱的研究

采用复合材料树脂传递模塑（RTM）工艺，利用一层含不锈钢纤维的导电布为屏蔽材料，制备了具有电磁屏蔽效能的玻璃纤维增强树脂基复合材料包装箱，该包装箱材料在1．0～4．0GHz电磁波范围内，电磁屏蔽效能最高可高达36dB左右，且与未含导电布的相同体系的复合材料相比，力学性能基本保持不变。     

Processing conditions for electromagnetic interference shielding effectiveness and mechanical properties of acrylonitrile-butadiene-styrene based composites

A conductive plastic was compounded in a twin screw extruder by incorporating conductive carbon fiber (CF) into an acrylonitrile-butadience-styrene (ABS) copolymer. The effects of various processing parameters prior to injection molding were investigated; then, the electromagnetic interference shielding effectiveness (EMI SE), fiber length, processability, and mechanical properties of the composite were studied. Results showed that the EMI SE of the composite increased as the final fiber length increased. The longer final fiber was produced by feeding fibers into the ABS melt at 240°C and 60 rpm. A more conductive network was formed by adding lubricants to the composite to reduce fiber damage and increase fiber dispersion. The increase of the fiber content affected processability. When the fiber content was higher than 40 phr (parts per hundred resin) in the composite, the average fiber length shortened. This study shows that better shielding can be obtained by adding a fiber at a rate higher than 30 phr. The best shielding obtained is about 30 decibels (dB).     

新型导电纤维填充型电磁屏蔽塑料

介绍了导电纤维填充型电磁屏蔽塑料的组成与特点,讨论了导电纤维填充型电磁屏蔽塑料的产品性能及其影响因素,综述了该材料在电子材料领域的应用及研究进展,提出了未来发展的方向。     

聚丙烯充填黄铜纤维导电性复合材料屏蔽性能的研究

本文就聚丙烯（ＰＰ）充填黄铜纤维导电性复合材料的屏蔽性能及黄铜纤维充填率与体积电阻率变化的关系进行了研究,并对电磁波屏蔽效果进行了测定。证明了塑料导电性复合材料的电磁波屏蔽效果是不能套用金属电磁波屏蔽理论的。两种黄铜纤维中,长径比愈大,电磁波屏蔽效果愈好。充填率体积分数为６％以上,复合材料具有导电性。充填率体积分数为８％以上复合材料可用于电磁波屏蔽。     

抗静电涤纶屏蔽性能的研究

在自制抗静电涤纶的基础上,均匀掺杂一些新的导电粒子,如碳纳米管(CNTs)、银粉和铁粉,研究其抗静电及屏蔽性能的变化。结果表明:自制抗静电涤纶的比电阻为5.6×10~9Ω·cm,在电磁波频率为30～100 MHz时,屏蔽效率小于10 dB。掺入铁粉和银粉后,其比电阻增大,屏蔽效果提高。当抗静电母粒和含CNTs质量分数为6%的PA6母粒质量比为7:3时,所得纤维的比电阻为2.1×10~9Ω·cm,在电磁波频率为30～100 MHz时屏蔽效率为20 dB以上,进一步涂敷自制导电涂料后,比电阻为1.9×10~9Ω·cm,屏蔽效率为25～30 dB,屏蔽性能良好。     

Partial replacement of carbon fiber by carbon black in multifunctional cement-matrix composites

Cement reinforced with discontinuous carbon fiber is known for its piezoresistivity-based strain sensing ability, its electrical conductivity and the consequent multifunctionality. The high cost of carbon fiber is disadvantageous. Both carbon fiber and carbon black (used with silica fume in the amount of 15% by mass of cement) increase the DC conductivity and the EMI shielding effectiveness of cement, but carbon fiber is more effective than carbon black. Partial (50%) replacement of carbon fiber by carbon black lowers the cost, in addition to increasing the workability, while the electrical conductivity and the electromagnetic interference shielding effectiveness are maintained. However, the partial replacement reduces the strain sensing effectiveness. Total replacement of carbon fiber by carbon black diminishes both the conductivity and the shielding effectiveness, further reduces the strain sensing effectiveness, decreases the compressive modulus and increases the compressive strain at failure, while the compressive strength is maintained. The increased workability due to the partial replacement enables a higher total conductive admixture content to be attained. The maximum total conductive admixture content is 3.5% by mass of cement. In contrast to fiber replacement, the addition of carbon fiber to cement with carbon black decreases the compressive strength, strain at failure and density.     

Shielding effectiveness of carbon-filled nylon 6,6

Electrically conductive resins can be made by adding electrically conductive fillers to typically insulating polymers. Resins with an electrical resistivity of approximately 10⁰ ohm-cm or less can be used for electromagnetic and radio frequency interference shielding applications. This research focused on performing compounding runs followed by injection molding and shielding effectiveness testing of carbon filled nylon 6,6 based resins. The three carbon fillers investigated included an electrically conductive carbon black, synthetic graphite particles, and a surface-treated polyacrylonitrile (PAN)-based carbon fiber. Conductive resins were produced and tested that contained varying amounts of these single carbon fillers. In addition, combinations of fillers were investigated by conducting a full 2³ factorial design and a complete replicate. The objective of this paper was to determine the effects and interactions of each filler on the shielding effectiveness properties of the conductive resins. Carbon fiber caused the largest increase in shielding effectiveness. Also, all the single fillers and combinations of fillers were statistically significant at the 95% confidence level, except the composite containing carbon black and synthetic graphite particles tested at 800 MHz. Polym. Compos. 25:407–416, 2004. © 2004 Society of Plastics Engineers.     

Dielectric property and electromagnetic interference shielding effectiveness of ethylene vinyl acetate‐based conductive composites: Effect of different type of carbon fillers

Carbon black, short carbon fiber (SCF), and multiwall carbon nano‐tube (MWNT)‐filled conductive composites were prepared from ethylene vinyl acetate copolymer. The dielectric property and electromagnetic interference (EMI) shielding of carbon black, MWNT, and SCF‐filled composites were studied with different filler loadings. The dielectric constant and loss of filled polymer composites is due to the formation of interfacial polarization in the polymer matrix. It was found that the dielectric constant, dielectric loss, and EMI shielding of filled composites depends on amount and type of filler loading. The results of different experiments have been discussed in the light of break down and formation of continuous conductive network in polymer matrix. The results indicate that these composites can be used as effective EMI shielding materials. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers.     

Preparation and EMI shielding properties of nickel‐coated PET fiber filled epoxy composites

Electrically conductive composites were prepared using epoxy resin (EP) as matrix and nickel‐coated polyethylene teraphthalate (PET) fibers as filler. The fibers were coated with nickel by plating and ultrasonic electroless deposition techniques. The coaxial transmission line method was used to measure the electromagnetic interference (EMI) shielding effectiveness of the nickel‐coated PET fiber/EP composites. The contents of nickel and phosphorus in the coating were determined by X‐ray photoelectron spectroscopy (XPS). As a result, the ultrasonic electroless nickel‐coated PET fiber/EP composites showed excellent electrical conductive capability and better EMI shielding effectiveness due to higher content of nickel and lower content of phosphorus in the coating than conventional plated nickel‐coated PET fiber/EP composites. POLYM. COMPOS., 27:24–29, 2006. © 2005 Society of Plastics Engineers