炭黑填充复合型导电聚合物的研究进展

在聚合物基体中添加导电炭黑以降低聚合物的电阻率,是目前最为常用的制备导电聚合物的方法。综述了炭黑填充复合型导电聚合物的研究进展。对影响复合材料导电性能及渗滤阈值的因素进行了讨论。重点介绍了使用共混聚合物作基体,并利用炭黑在共混基体中的非均相分布来降低炭黑用量的研究。     

酚醛树脂热解炭的电磁屏蔽性能研究

以热固性酚醛树脂(PF2123)为原料,经固化、成型和热解制备了块体碳材料,通过XRD、TG-DSC、激光拉曼光谱、SEM等对热解产物进行了表征,考察了热解温度和Fe Cl3催化剂对热解产物的微观形貌、有序化程度和X波段电磁屏蔽性能的影响。结果表明:热解的最终产物为无定形碳,1000℃热解时的残炭率为55%;随着热解温度的升高,热解炭的有序化程度提高,电导率增大,电磁屏蔽效能(EMI SE)先增大后减小,900℃热解时的电磁屏蔽效能最高达28.2 d B;添加占酚醛树脂质量0.5%的Fe Cl3催化剂在1000℃进行催化热解时,酚醛树脂热解炭内原位生成了大量多壁碳纳米管,形成了导电网络,提高了其电磁屏蔽性能;加入质量分数0.5%Fe Cl3催化剂对于1500℃热解试样的电磁屏蔽性能改善作用更为明显,特别是在低频段。     

导电电磁屏蔽塑料研究新进展

介绍了电磁屏蔽的基本理论,重点综述了3类主要的导电塑料即:表层导电型复合塑料、填充型复合塑料和本征导电高分子材料的研究应用现状,介绍了各类导电高分子电磁屏蔽材料的特点,并对其发展趋势做了展望。     

A Unique Double Percolated Polymer Composite for Highly Efficient Electromagnetic Interference Shielding

This study has developed a carbon nanotube (CNT)/ethylene vinyl acetate (EVA)/ultrahigh molecular weight polyethylene (UHMWPE) composite with a unique double percolated conductive structure, in which only 20 wt% of CNT enriched EVA is needed to form a continuous conductive network. Compared with conventional double percolated conductive polymer composites (CPCs) which require filler‐enriched polymer content up to 50 wt%, the low CNT/EVA content gives rise to an unprecedentedly increased effective CNT concentration in the CNT/EVA/UHMWPE composite. The double percolated composite exhibits electrical conductivity comparable to that obtained in CNT‐loaded single EVA composite with five times of CNT content. Only 7.0 wt% CNT gives the composite an electromagnetic interference (EMI) shielding effectiveness of 57.4 dB, much higher than that of mostly reported CNT and graphene based CPCs. Absorption is demonstrated to be the primary shielding mechanism due to the numerous interfaces between UHMWPE domains and CNT/EVA layers facilitating multiple reflection, scattering, and absorption of the incident microwaves. The construction of unique double percolated structure in this work provides a promising strategy for developing cost‐effective and high‐performance CPCs for use as efficient EMI shielding materials.

     

聚合物/碳纳米管复合导电材料的研究进展

基于碳纳米管(CNTs)的导电性能,对以碳纳米管为导电填料的复合导电材料的制备方法及国内外研究进展进行了综述。重点介绍了几种常见聚合物/CNTs复合导电材料的研究现状。展望了此类导电材料的发展前景。     

Nanocellular Foams of PS/PMMA Polymer Blends

A nanocellular PS/PMMA polymer blend foam was prepared, where bubble nucleation was localized in the PMMA domains. The blend, which contains dispersed nanoscale PMMA islands, was prepared by polymerizing MMA monomers in a PS matrix to form highly dispersed PMMA domains in the PS matrix by diffusion mixing. The resulting blend was foamed with CO₂ at room temperature. A higher depressurization rate at lower foaming temperature made the bubble diameter smaller and the bubble density larger, and a higher PS composition in the blend resulted in a larger bubble density. A void with 40–50 nm in average diameter and a pore density of 8.5 × 10¹⁴ cm^?3 was obtained as for the finest nanocellular foams.

     

Effectiveness of Polystyrene/Carbon Nanotube Composite in Electromagnetic Interference Shielding Materials: A Review

Polystyrene is an efficient thermoplastic having fine processability, chemical inertness, and mechanical performance. Technological advances have led to several industrial appliances of polystyrene-based materials ranging from insulation to electromagnetic interference shielding. In this state-of-the-art review, primarily structure and properties of carbon nanotube and polymer/carbon nanotube composite have been discussed. Carbon nanotube is considered as a brilliant filler for polymers. Therefore, a comprehensive discussion regarding high-performance polystyrene/carbon nanotube composite is presented. Main focus of review is the significance of electromagnetic interference shielding phenomenon in polystyrene/carbon nanotube composite. Owing to advantageous properties, these composite have potential to replace traditional shielding materials.     

CuxS/PAN 3D Nanofiber Mats as Ultra‐Lightweight and Flexible Electromagnetic Interference Shielding Materials

Shielding materials are becoming increasingly important, but present materials suffer from either insufficient mechanical stability or limited shielding properties. In this study, 3D flexible copper sulfide (Cu_xS)/polyacrylonitrile (PAN) nanofiber mats are developed via air spinning followed by chemical reaction with copper salt. The Cu_xS/PAN nanofiber mats exhibit an ultra‐lightweight density of 0.044 g cm^?3 and a thickness of 0.423 mm. Stable electromagnetic interference (EMI) shielding effectiveness (SE) (29–31 dB) of the Cu_xS/PAN composite is achieved in the frequency range of 500–3000 MHz. EMI SE per unit surface density of 16 655.92 dB cm² g^?1 is several orders of magnitude higher than most copper sulfide containing EMI shielding materials reported in literature. In addition, the introduction of the Cu_xS improves the thermal stability and launderability of the PAN mats giving the mats thermal, mechanical, and aqueous stability. Finally, the shielding mechanism of the Cu_xS/PAN nanofiber mats for electromagnetic waves is proposed     

导电炭黑/三元乙丙橡胶电磁屏蔽复合材料的性能研究

以三元乙丙橡胶(EPDM)为基体、导电炭黑为导电填料,并添加增塑剂,制备可挤出加工的炭黑/EPDM电磁屏蔽复合材料,研究炭黑和增塑剂的品种和用量对复合材料性能的影响.结果表明:添加结构度高、粒径小的导电炭黑有利于形成导电网络;随着炭黑用量的增大,复合材料的体积电阻率逐渐降低,当炭黑用量达到18份时,可以得到体积电阻率小于10Ω·cm的导电橡胶复合材料;添加20份石蜡油时,能有效降低胶料的门尼粘度.     

乙炔炭黑填充VMQ/EPDM共混导电橡胶的流变性能和结构分析

用孟山都流交仪测定了不同共混比的甲基乙烯基硅橡胶（ＶＭＱ）／ＥＰＤＭ共混混炼胶的流变性能；用网笼法测定了炭黑在共混体系两相中的比例；研究了薄通次数对共混硫化胶体积电阻率的影响；用透射电镜观察了硫化胶的形态。根据试验结果得出：适当并用比和炭黑填充量的ＶＭＱ／ＥＰＤＭ共混硫化胶具有高导电性的原因是：两相粘度相差较大，共混体系为明显的“海－岛”结构，而且炭黑在共混体系两相中的浓度不同；具有高导电性及其加工稳定性的ＶＭＱ／ＥＰＤＭ共混导电橡胶的最佳并用比例为８０／２０—７０／３０。     

炭黑填充复合型导电塑料制备工艺技术

在炭黑填充复合型导电塑料的制备过程中,工艺技术起着十分关键的作用。为此,应从多方面入手,优化材料组成与加工条件,如通过精心选择炭黑品种与加工助剂并细心调节其用量;采用混杂填充、多相复合基体控制炭黑的分布模式;优化混合与分散的程序以及工艺条件;针对各种不同的成型方法,优化加工参数等,获得所需要的导电特性,改善材料的综合性能。     

炭黑填充聚合物的导电性研究

研究了炭黑（ＣＢ）填充聚合物的导电特征,并着重讨论了ＣＢ种类、含量与材料体积电阻率的关系以及加工条件、交联剂和非导电填料对材料导电性的影响。     

Design of sandwich structure conductive polypropylene/styrene-butadiene-styrene triblock copolymer/carbon black composites with inherent morphological tunability

The insulator-conductor transition of conductive polymer composites (CPCs) can be ascribed to the fabrication of conductive networks, and the morphology of conductive networks plays a significant role in the electrical conductivity. This study presents CPCs with inherent morphology tunability which can be controlled by kinetic methods (i.e., mixing procedures and sequences, and polymer melt viscosity). Polypropylene (PP)/styrene-butadiene-styrene block copolymer (SBS) (50/50, in volume)/10 phr (parts per hundred of the polymer matrix) conductive carbon black (CB) composites prepared by different compounding sequences (PP/CB composites mixed with SBS, SBS/CB composites mixed with PP, and PP/SBS blend mixed with CB) are named as PC₁₀S, SC₁₀P, and PSC₁₀. With the difference between the phase morphologies, distribution, and dispersion of CB, the PP/SBS/CB composites realize seven orders of magnitude difference in resistivity. The volume resistivity (ρ_v) of PC₁₀S SC₁₀P and PSC₁₀ are 1.57 × 10¹, 1.68 × 10², and 4.88 × 10⁸ Ω m, respectively.     

聚合物/碳系填料发泡复合材料电磁屏蔽性能的研究进展

综述了聚合物/碳系填料发泡复合材料在电磁屏蔽领域应用的研究进展,重点讨论了各种碳系填料（石墨烯、碳纳米管、碳纤维）以及多组分碳系填料对发泡复合材料电磁屏蔽性能的影响及相关电磁屏蔽原理。结果表明,碳系填料的功能化、泡孔结构的调控、材料多层次结构的设计、制备工艺的优化等是改善聚合物/碳系填料发泡复合材料电磁屏蔽性能的有效途径。     

沥青基短切碳纤维/导电炭黑/丁腈橡胶复合材料的结构与性能研究

研究导电炭黑VXC72及沥青基短切碳纤维(CF)用量对丁腈橡胶(NBR)物理性能、导热及导电性能的影响。结果表明,随着导电炭黑VXC72用量的增大,NBR胶料和CF/NBR复合材料的拉伸强度、撕裂强度、定伸应力和热导率逐渐增大,体积电阻率逐渐降低,而且CF/NBR硫化胶的50%、100%定伸应力和热导率比NBR硫化胶有不同程度提高。当导电炭黑VXC72用量相同时,随着CF用量的增大,复合材料的拉伸强度、撕裂强度和拉断伸长率先减小后增大,热导率基本呈线性增加,体积电阻率明显降低。     

高密度聚乙烯导电塑料的性能研究

研究了导电炭黑的品种、含量和炭黑并用对高密度聚乙烯性能的影响。以脉动态硫化对改善ＨＤＰＥ／导电炭黑复合材料物性的影响。结果表明，炭黑并用能有效降低生产成本，而且保持了材料的性能，ＨＧ－４型电导炭黑填充ＨＤＰＥ具有很好的导电性，动态硫化法可以克服复合材料物性差的弱点，并能保持改性材料的高导电性；在ＨＧ－４型炭黑含量为７份时，材料的拉伸强度为１３ＭＰａ，断裂伸长率为３５０％，体积电阻率为２．１Ω·ｍ。     

导电炭黑/杜仲胶复合材料电磁屏蔽性能的研究

采用机械共混法制备了导电炭黑/杜仲胶复合材料,研究炭黑用量对复合材料电性能和电磁屏蔽性能的影响。结果表明：随着炭黑用量的增加,复合材料的导电率增大,当炭黑用量为25份时,导电率达到3.3S/cm,导电率遵循导电逾渗规律;复合材料的Payne效应越来越大,有利于形成稳定的导电网络;复合材料的拉伸强度逐渐增大后略微降低,断裂伸长率先增加后逐渐下降。复合材料的屏蔽效能增大,当炭黑用量为20份时,屏蔽效能最高能达到33.2dB,可以满足一般工业或者商业用电子设备的要求。     

不同炭黑对聚丙烯／炭黑复合材料导电性能的影响

研究了四种不同的导电炭黑与聚丙烯复合制得的复合材料的体积电阻率与炭黑含量的关系，确定了复合体系中炭黑的渗滤阈值。用扫描电镜(SEM)观察了不同炭黑含量的复合材料的断面形貌，用透射电镜(TEM)观察分析了四种炭黑的结构及粒径，并对其比表面积进行了测定。结果表明：炭黑不同，得到的复合材料的渗滤阈值有很大差别。炭黑结构性越高，比表面积越大，粒径越小，其导电性能越好，得到的渗滤阈值越低。特别是具有空壳结构的炭黑，其渗滤阈值明显低于其他三种炭黑。     

炭黑/聚氨酯熔纺导电纤维结构与性能的研究

将导电炭黑混入到热塑性聚氨酯中,经熔融纺丝制得导电纤维。随着炭黑含量增加,炭黑/聚氨酯共混体系的黏度增大,玻璃化转变温度提高。炭黑含量在13%￣16%时,炭黑在体系中的分布较为均匀,纤维的导电性能较好,力学性能可以满足应用要求。