以聚乳酸为基体的导电高分子复合材料研究进展

概括了导电填料种类、结构及成型方法、工艺条件等因素对单相聚乳酸(PLA)基导电高分子复合材料(CPCs)电学性能的影响,介绍了PLA基多相CPCs中导电填料选择性分布机制和较低逾渗值的机理,总结了PLA基CPCs在有机溶剂中的响应行为,并对材料的应用前景进行了展望。     

CB/PA 6/HDPE导电高分子复合材料的拉伸敏感特性

研究了含导电超细纤维网络的炭黑(CB)/尼龙6(PA 6)/高密度聚乙烯(HDPE)导电高分子复合材料的拉伸敏感行为。结果表明:复合材料的电阻随拉伸变形的增大呈指数形式增加。在循环拉伸试验中,复合材料电性能在低应变(3%)时稳定性、可重复性好;在高应变(6%)时响应度高,但可重复性差。此外,多次拉伸循环可明显提高应变-电阻响应的稳定性。这与该过程中导电网络的结构演变密切相关。     

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。     

导电炭黑在抗静电聚合物中应用

将特殊的炭黑粒子均匀分散在聚合物基体中,能在一定温度范围内有效提高材料电阻值,可形成一种复合型导电高分子材料。本文综述了导电炭黑填充聚合物的研究进展,对影响复合材料的导电性能及因素进行了探讨。重点介绍了使用共混聚合物作基体,利用特种导电炭黑改善聚合材料的抗静电性的研究。     

氟橡胶复合导电材料性能

研究以氟橡胶为基体树脂,炭黑、石墨和碳纤维为导电填料的导电复合高分子材料中,炭黑、石墨、碳纤维及三者之间的配比和混炼时间对复合材料导电性能和机械性能的影响,制备出体积电阻率小于1Ω·cm的氟橡胶复合导电材料。     

聚烯烃类弹性体导电复合材料的制备与性能研究

将炭黑(CB)和碳纤维(CF)导电粒子加入到新型聚丙烯弹性体(Vistamaxx)与聚丙烯(PP)基体树脂中,共混制备导电复合材料。通过体积电阻率测试、力学性能测试和加工流变性能测试,得到了体积电阻率最低为0.47Ω.cm,拉伸强度为6.6 MPa,断裂伸长率为250%,具有良好加工性能的导电复合材料。     

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。     

高分子基导电复合材料非线性导电行为及其机理(Ⅱ)量子力学隧道效应理论

简述了高分子基导电复合材料非线性导电行为的概念,详细讨论了高分子基导电复合材料非线性导电行为的机理——量子力学隧道效应理论及其它理论。高分子基导电复合材料的非线性导电行为是几种效应的综合过程:当导电填料的体积分数较小时,导电粒子无法形成导电通道,此时只有量子力学隧道效应在起作用;当导电填料的体积分数较大时,复合材料的导电行为是导电通道和隧道效应共同作用的结果。     

导电高分子复合材料的电磁屏蔽效能分析

本文分析了电磁屏蔽的基本原理,着重探讨了导电填料、高分子基体以及复合工艺等因素对导电高分子复合材料电磁屏蔽效能的影响。     

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。     

Anisotropic multilayer conductive networks in carbon nanotubes filled polyethylene/polypropylene blends obtained through high speed thin wall injection molding

To prepare composites with anisotropic conductive networks, electrical conductive polymer composites (CPCs) consisting of polypropylene (PP) and carbon nanotubes (CNTs) filled polyethylene (PE) are fabricated through high speed thin-wall injection molding. Morphological study demonstrates that CNTs are localized in PE phase while the alternating multilayer structure with different polymer phases elongated as well as conductive network oriented parallel to flow direction is observed. To form such alternating layered structure, the dispersed phases are firstly deformed into discontinuous layers, and finally further deformed into wide and regular continuous alternating layers. In term of the mechanism behind this, the good viscosity match, low interfacial tension between different polymer components, short relaxation time and high shear rate are thought as important issues. The anisotropic conductive behavior of these CPCs, i.e. conductive in longitudinal (parallel to flow direction) and transverse (perpendicular to flow direction) direction but non-conductive in thickness direction, is contributed by the insulating PP layer which cuts off the conductive networks in the core layer. More importantly, much better electromagnetic interference (EMI) shielding ability is obtained for these CPCs with alternating multilayer conductive networks comparing with the same polymer blends with isotropic conductive networks, despite of the fact that much lower resistivity is obtained for the later. This indicates great potential of these anisotropic CPCs for electronic applications. Moreover, this study has shed some light on the potential use of such alternating multi-layered structure to prepare a range of multi-functional materials.     

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     

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.     

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。     

Modified resistivity–strain behavior through the incorporation of metallic particles in conductive polymer composite fibers containing carbon nanotubes

Eutectic metal particles and carbon nanotubes are incorporated into a thermoplastic polyurethane matrix through a simple but efficient method, melt compounding, to tune the resistivity–strain behavior of conductive polymer composite (CPC) fibers. Such a combination of conductive fillers is rarely used for CPCs in the literature. To characterize the strain‐sensing properties of these fibers, both linear and dynamic strain loadings are carried out. It is noted that a higher metal content in the fibers results in higher strain sensitivity. These strain‐sensing results are discussed through a morphological study combined with a model based on the classic tunneling model of Simmons. It is suggested that a high tunneling barrier height is preferred in order to achieve higher strain sensitivity. Copyright © 2012 Society of Chemical Industry     

Lightweight and flexible sensors based on environmental-friendly poly(butylene adipate-co-terephthalate) composite foams with porous segregated conductive networks

Constructing the microcellular structure in the conductive polymer composites (CPCs) is a promising approach to improve the sensitivity and durability of the piezoresistive sensor. Selectively placing the conductive fillers, to form the segregated network between the polymer region, can effectively improve the electric performance of CPCs. However, few researches have focused on the influence of the polymer bead size on the segregated network and the large-scale production of spherical polymer beads with low cost is still difficult to realize. Herein, plenty of regular-shaped poly(butylene adipate-co-terephthalate) (PBAT) beads were manufactured through underwater pelletizing process, which was further coated with carbon nanotube (CNT) particles with the assistance of ball milling technology, and eventually the sensor was successfully fabricated through supercritical carbon dioxide (scCO₂) bead foaming technology. The lightweight and flexible sensor exhibited the uniform cell structure with the mean cell size of 51.0 μm and cell density of 3.9 × 10⁸ cells/cm³ when the pelletizing cutter speed was 2500 rpm and the foaming temperature was 117.5°C. And the conductivity of the sensor reached 6.5 S/m incorporated with 3 wt% CNT, which possessed high sensitivity, good stability and long-term durability, attributed to its excellent microcellular structure and segregated conductive network.     

Temperature and time dependence of electrical resistivity in an anisotropically conductive polymer composite with in situ conductive microfibrils

An anisotropically conductive polymer composite (ACPC) based on conductive carbon black (CB) and binary polymer blend of polyethylene (PE) and polyethylene terephthalate (PET) was successfully fabricated under shear and elongational flow fields. The PET phase formed in situ the aligned conductive microfibrils whose surfaces were coated by CB particles. This ACPC material exhibited a strong electrical anisotropy within a broad temperature range. When the ACPC samples were subjected to isothermal treatment (IT), they showed anomalous variations of the positive temperature coefficient (PTC) and negative temperature coefficient (NTC) effects. The PTC intensity was attenuated gradually with the increase of the IT time, and the NTC intensity was nearly eliminated after IT of 8 or 16 h. Beyond 16 h, the resistivity in the NTC region rose anomalously with the temperature after the elimination of NTC effect, which was the result of much transformation from the potential pathways to the intrinsic pathways due to the disordering of oriented conductive microfibrils. When the amount of potential pathways was very small, the effect of the intrinsic pathway separation surmounts that of the potential pathways, leading to the anomalous resistivity increase in the NTC region. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012