电磁屏蔽材料的发展现状及未来发展趋势

介绍了电磁屏蔽原理与导电聚合物复合材料（CPCs）特点,论述了不同应用场合下CPCs的物理特性（柔性、硬质、涂覆）,对近年来国内外电磁屏蔽材料中导电填料种类（金属、碳基、金属碳化物氮化物MXene）及其制备工艺进行了详细汇总分析,并对电磁屏蔽材料未来发展方向进行了展望。     

CB/PLA与CB/RF/PLA导电高分子复合材料气敏性能对比

通过熔融共混法制备了炭黑(CB聚乳酸(PLA和CB/苎麻纤维(RFPLA导电高分子复合材料(CPCs。扫描电镜(SEM观察发现导电填料在CB/PLA中分散良好。通过预混合的方法,可以先使CB和PLA良好接触,随后的熔融加工过程中,CB/RF/PLA中CB粒子分布在RF附近,这种纤维搭接的CPCs逾渗值比CB/PLA更低。气敏测试对比研究发现,含RF的导电复合材料在不良溶剂中响应度高,重复性好;在良溶剂中,响应时间长,气敏稳定性好。为制备逾渗值低,气敏性能优良的可降解CPCs提供了新思路。     

CPCs在应力场下的性能演变及机理研究进展

综述了导电高分子复合材料(CPCs)在压缩应力场、拉伸应力场及应力-应变循环力场中电阻率随应力、应变、循环次数及时间等的变化规律,分析了CPCs在上述应力场中电阻率变化与其微观结构演变之间的关系,结合导电粒子在高分子基体中的位置改变及导电粒子与高分子基体间相互作用,归纳了CPCs电性能在上述外力场中的演变机制。针对目前该复合材料在上述循环应力场中出现的磁滞效应和可重复性差等问题,归纳了相应的改善方法。简要概括了CPCs的工业应用。     

PLA/PPy复合材料的制备及表征

以吡咯(Py)为原料,通过原位聚合法合成聚吡咯(PPy)导电粒子,通过PPy粒子对聚乳酸(PLA)进行改性,制备PLA基导电复合材料,并对其形貌、力学性能及导电性能进行测试。结果表明:PPy可以与PLA基体呈现一种紧密结合的状态;PLA/PPy(5%)导电复合材料综合性能最佳,其拉伸强度为51.2 MPa、断裂伸长率为163.5%、电导率为4.12×10~(-5) S/cm。     

注塑成型导电高分子复合材料研究进展

综述了注塑成型导电高分子复合材料(CPCs)的典型微观结构,总结了提高注塑成型CPCs力学性能和电性能的方法,提出了优化工艺并进行复合材料微观结构设计是拓宽注塑成型CPCs应用领域的关键。     

复合型导电高分子材料的液体敏感行为研究进展

综述了复合型导电高分子材料(CPCs)在有机溶剂中的液体敏感响应行为特性和CPCs液体敏感行为的影响因素。基于上述响应特性和影响因素,概括了CPCs液体敏感响应行为的发生机制。对CPCs液体敏感器件在化工、炼油、食品、船舶、环境等领域的应用进行了总结和展望。     

复合型导电高分子材料温敏行为研究进展

复合型导电高分子材料(CPCs)的温敏响应行为主要包括正温度系数效应(PTC)和负温度系数效应(NTC)等。本文综述了PTC型CPCs的研究进展,包括PTC行为的发生机理,PTC强度及PTC行为可重复性的调控方法;概括了PTC后NTC行为的消除方法。分析了NTC型CPCs的工作机制,并对CPCs温敏行为的研究热点和难点进行了展望。     

碳系导电油墨填料的研究进展

导电油墨起源于导电涂料,印刷电子行业的兴起产生了对导电油墨的研发需求。本文综述了碳系导电油墨填料的研究现状、导电机理、应用前景及其发展方向。首先概述了传统碳系导电油墨填料(石墨、炭黑、碳纤维及其混合物)以及新型碳系导电油墨填料(碳纳米管、石墨烯)的研究进展,重点分析了传统碳系填料的研究方向及手段,解释了新型碳系填料应用于导电油墨的优越性。然后从宏观和微观层面概述了当前主流的几种导电机理的基本原理和适用范围,并指出了目前对油墨导电性能的研究只能定性分析而不能定量描述的局限性。最后,重点介绍了两种新型碳系导电油墨填料的最新研究进展和应用方向,特别指出了当前对碳纳米管和石墨烯填料的研究亟需解决的问题,总结了二者今后的研究重点和研究趋势。     

高导电碳系填充聚乙烯复合材料的研究进展

系统介绍了碳系分散体(碳黑、石墨、碳纤维、碳纳米管等)作为填料填充聚乙烯形成聚乙烯基导电复合材料的研究进展.并根据国内外高导电碳系填充聚乙烯复合材料研究成果的对比分析,对其今后发展提出建议.     

复合导电高分子材料的改性及应用研究进展

介绍了复合导电高分子材料的主要构成和分类,综述了碳系复合导电高分子材料[如炭黑(CB)填料型、碳纳米管(CNTs)填料型和石墨烯填料型等]、金属系复合导电高分子材料和金属氧化物系复合导电高分子材料的改性进展。最后对复合导电高分子材料的应用和发展前景进行了展望。     

Partially miscible poly(lactic acid)‐ blend‐poly(propylene carbonate) filled with carbon black as conductive polymer composite

BACKGROUND: Conductive polymer composites (CPCs) can be obtained by filling polymer matrices with electrically conductive particles, and have a wide variety of potential applications. In the work reported, the biodegradable polymer poly(lactic acid) (PLA) as a partially miscible blend with poly(propylene carbonate) (PPC) was used as a polymer matrix. Carbon black (CB) was used as the conducting filler. RESULTS: Fourier transform infrared spectroscopy revealed interactions between matrix and CB filler; this interaction was stronger in PPC‐blend‐CB than in PLA‐blend‐CB composites. A rheology study showed that low‐viscosity PPC could improve the fluidity of the CPCs, but decrease that of CB. With increasing CB content, the enforcement effect, storage modulus and glass transition temperature increased, but the elongation at break decreased. CPCs exhibited the lowest electrical percolation thresholds of 1.39 vol.% CB when the content of PPC in PLA‐blend‐PPC was 40 wt%. The conductivity of CPCs containing 5.33 vol.% CB and 40 wt% PPC reached 1.57 S cm^?1. Scanning electron microscopy revealed that CB exhibits a preference for dispersion in the low‐viscosity phase (PPC) of the multiphase matrix. CONCLUSION: In the presence of CB, partially miscible PLA‐blend‐PPC could form multi‐percolation CPCs. Moreover, the combination of PLA and PPC with CB broadens novel application of both renewable polymers and CPCs. Copyright © 2008 Society of Chemical Industry     

电磁屏蔽填料的制备及研究进展

综述了电磁屏蔽导电复合填料的发展现状,分别介绍了金属系导电填料、碳系导电填料和金属-碳系导电填料的制备及研究进展。进一步分析了三种导电填料的优缺点,并对其进行了比较,同时对未来碳系填充型电磁屏蔽材料的发展趋势提出了建议。     

高分子基导电复合材料研究进展

高分子基导电复合材料凭借其导电性、稳定性、加工性等方面的明显优势,成为导电材料研究的热点。系统地介绍了复合型导电高分子材料的导电机理、制备方法并对导电复合材料的应用进行了总结,并展望了导电高分子复合材料的发展趋势。     

复合型导电高分子泡沫的研究进展

综述了以热固性高分子和热塑性高分子为基体的复合型导电泡沫的制备方法,主要包括化学发泡法、物理发泡法和导电填料浸渍泡沫法等。总结了复合型导电高分子泡沫对温度等外场的响应行为,并对材料的应用前景进行了展望。     

Preparation of conductive polylactic acid/high density polyethylene/carbon black composites with low percolation threshold by locating the carbon black at the Interface of co-continuous blends

In the current study, polylactic acid/high density polyethylene/carbon black (PLA/HDPE/CB) composites are prepared via a two-step method. A double percolation network with co-continuous structure and filler distribution at the interface is constructed to design conductive polymer composites with low percolation threshold. The controllable distribution of CB at the interface is achieved by appropriate processing procedures involved mixing sequence and mixing time by taking advantage of the migration of CB from the unfavorable PLA phase to the favorable HDPE phase. Morphology characterization reveals that when the mixing time of the added HDPE is 3 min, the formation of co-continuous structure of PLA/HDPE (60/40, w/w) is observed, and CB particles migrate to the co-continuous interface. The electrical conductivity measurement shows that such double percolation conductive network reduces the percolation threshold of PLA/HDPE/CB to 2.42 wt%. The rheological property proves the establishment of particle percolation network, and the rheological percolation threshold is determined as 1.20 wt%. The prepared PLA/HDPE/CB composite by the two-step method displays a notably low percolation threshold than that prepared by one-step simultaneous mixing. Moreover, this strategy presents a high potential application in the fabrication of conductive polymer composites involving other miscible multiphase systems.     

Conductive polymer tape containing highly oriented carbon nanofillers

The effect of the orientation of carbon fillers with different aspect ratios on the resistivity and morphology of conductive polymer composites (CPCs) based on polypropylene was investigated in this study. Multiwall carbon nanotubes (MWNTs) and carbon black (CB) were used as conductive fillers. The CPCs were made by melt compounding, hot pressing, and solid‐state drawing. The alignment of the filler was observed after solid‐state drawing. The resistivity of the composites increased with the draw ratio at relatively low carbon filler loadings (<20 wt %), whereas it remained unchanged at a high filler loading (20 wt % CB). Orientation‐promoted anisotropy of the conductive network was observed in both the morphology and resistivity. MWNTs were found to be better at maintaining a percolating network under large deformations than CB because of their larger aspect ratio and their entangled network structure. The experimentally obtained resistivity was analyzed with percolation theory, and this indicated that the initial three‐dimensional conductive network was deformed into a two‐dimensional network after solid‐state drawing for the composites containing CB. The three‐dimensional network was found in isotropic CPCs containing MWNTs with the same analysis. Theoretical analysis using excluded volume theory was in good agreement with results obtained experimentally. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Conductive polymer composites with segregated structures

Conductive polymer composites (CPCs) have generated significant academic and industrial interest for several decades. Unfortunately, ordinary CPCs with random conductive networks generally require high conductive filler loadings at the insulator/conductor transition, requiring complex processing and exhibiting inferior mechanical properties and low economic affordability. Segregated CPC (s-CPC) contains conductive fillers that are segregated in the perimeters of the polymeric granules instead of being randomly distributed throughout the bulk CPC material; these materials are overwhelmingly superior compared to normal CPCs. For example, the s-CPC materials have an ultralow percolation concentration (0.005–0.1 vol%), superior electrical conductivity (up to 10⁶ S/m), and reasonable electromagnetic interference (EMI) shielding effectiveness (above 20 dB) at low filler loadings. Therefore, considerable progress has been achieved with s-CPCs, including high-performance anti-static, EMI shielding and sensing materials. Currently, however, few systematic reviews summarizing these advances with s-CPCs are available. To understand and efficiently harness the abilities of s-CPCs, we attempted to review the major advances available in the literature. This review begins with a concise and general background on the morphology and fabrication methods of s-CPCs. Next, we investigate the ultralow percolation behaviors of and the elements exerting a relevant influence (e.g., conductive filler type, host polymers, dispersion methods, etc.) on s-CPCs. Moreover, we also briefly discussed the latest advances in the mechanical, sensing, thermoelectric and EMI shielding properties of the s-CPCs. Finally, an overview of the current challenges and tasks of s-CPC materials is provided to guide the future development of these promising materials.     

电热混凝土复合材料的研究进展

综合国内外文献及作者的最新研究成果,从单掺和复掺导电组分两个方面介绍了目前电热混凝土复合材料的研究进展,侧重于介绍电热混凝土的导电性、导电相掺量、电热性能和初步现场试验结果.