填充型多相聚合物导电复合材料的PTC效应

以聚丙烯和低密度聚乙烯共混物为基体,用碳黑为填充材料制备了复合导电材料,导电性能的测试表明多相复合体系的渗滤阈值低于两相复合体系的渗滤阈值。对复合材料PTC效应的分析以及对材料的热性能测试结果表明碳黑在共混体系中的分布。同时探讨了体系碳黑含量的变化对PTC效应的影响。     

聚合物共混体系／黏土纳米复合材料多相形态的研究进展

论述了聚合物共混体系/黏土纳米复合材料内部多相结构形态研究的最新进展；从共混聚合物基体对黏土的分散形态以及黏土对不相容共混基体相结构的影响两方面总结了多相形态的影响因素；探讨了相形态改善、反转的机理。     

CB填充HDPE/POE复合材料阻-温特性的研究

以乙炔碳黑(ACET)为导电填料,高密度聚乙烯/乙烯-辛烯共聚物(HDPE/POE)为基体,制备了碳黑(CB)填充HDPE/POE复合材料,并研究了该材料的电阻率-温度变化规律。     

0-3型钛酸锶钡与聚四氟乙烯复合材料的冷烧结制备与介电性能研究

0-3型钛酸锶钡(BST)与聚四氟乙烯(PTFE)复合材料是一种新型的陶瓷/高聚物功能复合材料,可以兼具BST材料与PTFE材料的优点,可表现出较高的介电常数和介电可调性。但是受聚合物相介电常数低的限制,常规方法(流延法)制备的以聚合物为基体,以陶瓷为填充相的复合材料的介电常数基本在100以下。为了进一步提高BST/PTFE复合材料的介电性能,本研究采用一种新型烧结工艺——冷烧结工艺实现BST陶瓷与PTFE高聚物的共烧。在试验中以BST为基体,引入体积比例为5%的PTFE,并引入固相八水合氢氧化钡(Ba(OH)₂·8H₂O)作为过渡液相以辅助烧结过程进行,制备0-3型BST/PTFE复合材料,并探究了不同冷烧结条件下复合材料的介电性能。结果表明,复合材料样品在冷烧结温度为275 ℃,压力为200 MPa,时间为2.5 h的条件下,介电常数可达到500以上(25 ℃,1 kHz)。相对于常规制备工艺,冷烧结工艺制备出的复合材料的介电常数有很大改进,这对陶瓷/高聚物功能复合材料的低温制备与研究有一定参考意义。     

液晶高分子原位复合材料的增强机理

综述了热致性液晶与热塑性工程树脂基质共混形成自增强的热塑性复合材料方面研究工作的进展．分析和评述了液晶含量、作用流场、两相粘度比、界面张力、液晶与基体的相容性以及微纤的分子取向对复合材料中微纤的形成以及力学性能的影响．     

共混丙纶的结构和亲水性

用X衍射、扫描电镜、差热分析、光学显微镜对共混丙纶的形态、结构进行了研究。结果表明,P-36D/PP和P-528/PP共混丙纶,均为基体-微纤型两相结构。P-36D和P-528的加入,对共混丙纶的结晶性影响不大,对形态结构有很大影响。共混丙纶的亲水性(吸湿性和保水性)与纤维的形态、结构、组成高聚物的性质以及共混比有着密切关系。 P-528/PP共混丙纶的亲水性,明显高于P-36D/PP共混丙纶。     

SBS/导电炭黑复合材料的导电性能研究

导电高分子复合材料是高聚物与导电填料共混制成的功能性材料。导电炭黑由于具有分散性好、可赋予高聚物较好的导电性能而广泛用作导电填料。本工作探讨导电炭黑和混炼工艺条件对苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）／导电炭黑复合材料导电性能的影响。     

天然橡胶/丁苯橡胶/Ni/MWCNTs复合材料的结构与吸波性能

以Ni和多壁碳纳米管(MWCNTs)为填料,天然橡胶(NR)/丁苯橡胶(SBR)共混物为基体,采用机械共混法制备了性能优异的NR/SBR/Ni/MWCNTs多维复合材料,研究了填料共混及其组成对复合材料微观形貌和电磁损耗网络行为的影响.结果表明:Ni与MWCNTs共混有助于促进两者在橡胶基体中的分散,形成更优的双填料网...     

聚脲基体复合材料抗爆耐冲击性能研究进展

随着聚脲基体复合材料在结构防护领域的大量应用,其抗爆耐冲击性能获得广泛研究。本文基于聚脲基体复合材料在结构防护领域的研究现状,介绍了聚脲材料作为高聚物弹性体的抗爆性能,综述了聚脲-纤维复合材料的研究进展,阐述了聚脲材料抗冲击性能机理。指出聚脲作为高聚物弹性体对防护结构具有较好的抗冲击防护效果,可与纤维组成高强度、高弹性模量和可吸收爆炸冲击能量的复合材料,在防护结构抗爆炸毁伤领域具有可观前景。     

共混高聚物—炭黑复合材料的导电特怀

本文讨论了共混高聚物－ＣＢ复合材料比之单一高聚物－ＣＢ复合的不同的导电特性及其作用机制。     

炭黑在高分子聚合物中的导电性研究

以EVA为高分子聚合物，采用不同级别的导电炭黑，研究了导电炭黑填充高分子聚合物的导电性，讨论了不同级别和不同用量的导电炭黑在聚合物中的分散性，以及对高分子聚合物导电性的影响。实验结果表明，导电炭黑高分子聚合物的导电性主要取决于不同级别的导电炭黑的表面性和结构等特性、炭黑的不同用量以及导电炭黑的聚集体在高分子聚合物的分散程度。     

Conductive polymer blends filled with carbon black: Positive temperature coefficient behavior

Electrical conductivity and positive temperature coefficient (PTC) behavior of carbon black (CB) filled incompatible polyblends of ethylene-vinyl acetate copolymer/low density polyethylene (EVA/LDPE) were investigated. In comparison with single polymer systems, more possibilities for tailoring composite performance were brought about with the employment of polymer blends as matrix resins in conductive composites. Based on the concepts of double percolation and two-step percolation, PTC-type composites with balanced performance, improved processability, and reproducibility can be made. Thermodynamical and kinetic factors including interfacial energy, melt viscosity, blending ratio, melt mixing time, sequence of blending as well as CB concentration were shown to be closely related to the ultimate properties obtained.     

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。     

HDPE/ PC/CB复合体系双逾渗行为的研究

以炭黑(CB)为导电填料,填充到2种不相容的高聚物高密度聚乙烯(HDPE)和聚碳酸酯(PC)基体中制备高分子基正温度效应(PTC)材料.研究表明,CB在HIRE中的逾渗阈值约为20%;HDPE/PC/CB三元复合体系形成了双逾渗行为,当HDPE/PC质量比为40/60时,三元复合体系具有较好的PTC及PTC重复性.     

纳米导电炭黑防静电PTFE涂层的研究

以纳米导电炭黑粉体XC-72R作为导电填料对高分子材料进行防静电处理。先对纳米导电炭黑粉体进行球磨分散,制得固含量为35wt%的高稳定性导电浆料,再将该浆料添加到聚四氟乙烯(PTFE)乳液中,并涂布到玻璃纤维布上,经380℃烧结制得防静电PTFE涂层。当炭黑粉体的添加量为3.98wt%时,涂层的电阻率可达106Ω.cm,具有很好的防静电效果。     

Effect of some service conditions on the electrical resistivity of conductive styrene–butadiene rubber–carbon black composites

Conductive polymer composites were prepared using vulcanized styrene–butadiene rubber as a matrix and conductive carbon black as a filler. The filler loading was varied from 10 to 60 phr. The volume resistivity was measured against the loading of the carbon black to verify the percolation limit. The electrical conductivity of filled polymer composites is attributed to the formation of some continuous conductive networks in the polymer matrix. These conductive networks involve specific arrangements of conductive elements (carbon black aggregates) so that the electrical paths are formed for free movement of electrons. The effects of temperature and pressure on the volume resistivity of the composites were studied. The volume resistivity of all the composites increased with increase in temperature, and the rate of increase in the resistivity against temperature depended on the loading of carbon black. The change in volume resistivity during the heating and cooling cycle did not follow the same route, leading to the phenomena of electrical hysteresis and electrical set. It was found that the composites with 40 and 60 phr carbon black become more conductive after undergoing the heat treatment. Generally, all the composites showed a positive temperature coefficient of resistivity. The volume resistivity of all the composites decreased with increase in pressure. The relaxation characteristic of the volume resistivity of the composites was studied with respect to time under a constant load. It was found that the volume resistivity of the compressed specimen of the composites decreased exponentially with time. It was observed that initially a faster relaxation process and later a slower relaxation process occurred in these composites. Some mechanical properties of these composites were also measured to confirm the efficacy of these composites for practical applications. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2179–2188, 2004     

炭黑在两相高分子导电复合材料中选择性分布研究进展

综述了影响炭黑在两相高分子复合材料中选择性分布的因素及炭黑的选择性分布对复合材料电性能的影响,指出了炭黑填充导电高分子复合材料的研究方向。     

导电复合橡胶用导电填料的应用研究进展

对导电复合橡胶用导电填料如炭系、金属系、颗粒表面镀金属等的种类、性质等因素对复合橡胶材料导电率的影响及应用进行了综述。也对采用新型的填料即本征导电聚合物主要是聚苯胺填充制备导电复合橡胶的研究进展进行了综述。炭系是目前制备导电复合橡胶主要的导电填料,但有污染,不适合制备有颜色要求的导电材料,金属系、颗粒表面镀金属的比重大,在聚合物中分散较困难,也不太适合于有比重要求的制品。本征导电聚合物导电填充填料是制备导电复合橡胶发展的一个重要方向,可以解决不熔难溶造成的在聚合物中分散性差的问题。     

导电PVC的制备和性能研究

通过熔融共混法制备了炭黑/聚氯乙烯(PVC)导电复合材料,研究了炭黑含量对复合材料导电性能、力学性能和微观结构的影响。结果表明:当炭黑含量大于15%时,炭黑颗粒在PVC基体中形成了导通网络;炭黑的加入使导电PVC复合材料的拉伸强度先升高后下降,在其含量为20%时达到最大值,但同时使复合材料的冲击性能显著降低。     

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.