炭黑/高密度聚乙烯导电纤维纺丝工艺探索

以高密度聚乙烯为基体,炭黑为导电介质共混得到导电母粒,通过熔融纺丝法制得炭黑/高密度聚乙烯共混导电纤维。考察了炭黑含量和粒径对可纺性的影响,发现炭黑含量为5%,粒径为40～50nm时,熔体可顺利纺丝,且所得纤维具有较好的导电性。通过多次试纺,确定了合适的纺丝工艺。     

纤维级碳黑导电母粒研究进展

介绍了纤维级碳黑(CB)导电母粒的制备方法,分析了偶联剂用量、分散剂用量、共混体系组成、螺 杆转数和混合时间等对纤维级CB导电母粒导电性的影响。指出提高CB的分散性,降低导电母粒的电阻 值,提高导电母粒的可纺性是开发高品质纤维级CB导电母粒的关键。     

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。     

PA 6/碳纳米管共混导电单丝的制备和性能研究

将炭黑导电母粒、碳纳米管母粒、聚己内酰胺(PA 6)切片按一定质量配比共混,在双螺杆机挤压下,经注带、冷却制得共混切片,将共混切片在卧式纺丝机上进行纺丝,经拉伸、上油等制得导电单丝,研究了不同配比的导电单丝的导电性能和力学性能。结果表明:随着共混切片中炭黑和碳纳米管总量的减少、PA 6含量的增加,其纺丝时最大可拉伸倍数呈现单调上升;炭黑与碳纳米管在导电单丝拉伸过程中具有协同作用,拉伸后的导电单丝的表面电阻可达到10~4Ω/cm水平;炭黑母粒质量分数为40%,碳纳米管母粒质量分数为30%,PA 6质量分数为30%时,制得的导电单丝导电性能和力学性能好,其表面电阻为1.5×10~4Ω/cm,电阻率为4.2×10~5Ω·cm,断裂强度为12.2 cN/tex,断裂伸长率为12.3%。     

高导电粗旦聚乙烯纤维的制备及性能研究

以高密度聚乙烯(HDPE)和导电炭黑(CB)为原料,聚离子液体(P(MIMH-AD))为分散剂,利用熔融混合的方法制备导电母粒,并通过单螺杆纺丝机使导电母粒与HDPE切片进行熔融纺丝制得导电HDPE纤维,研究了聚离子液体对CB的分散作用,以及导电HDPE纤维的导电性能和力学性能。结果表明：聚离子液体P(MIMH-AD)不仅在水溶液中可以有效分散CB,在熔融状态下也可以通过π-π的相互作用使CB在导电母粒HDPE/CB/P(MIMH-AD)中均匀分散;制备的导电HDPE初生纤维经拉伸后,断裂强度提高约5倍,达到109 MPa,断裂伸长率达到124%,电导率提高至400.4Ω·m,但仍可以点亮灯泡,力学性能得到提高的同时,具有良好的导电性能。     

可导电玻璃纤维增强聚丙烯材料的性能分析

研究了导电炭黑(CB)的不同添加方式、不同导电炭黑母粒含量对玻璃纤维增强聚丙烯材料的表面电阻率、力学性能和熔体流动速率的影响.结果表明,导电炭黑母粒对聚丙烯材料的分解温度没有影响;导电通路的形成与导电炭黑在玻璃纤维增强聚丙烯体系中的分散性有关;添加导电炭黑母粒体系中更有利于形成导电通路;当导电炭黑母粒添加至40％时,玻...     

含碳纳米管导电PET纤维的研究

将纳米组装高分子(PEEM)作为载体,使碳纳米管(CNT)及金属氧化物在其中充分分散,分别制成CNT母粒和导电剂,再与聚酯切片共混纺丝制备导电PET纤维。探讨了CNT母粒含量、导电剂含量、导电剂／CNT母粒配比、纤维的导电性能以及导电纤维的耐洗涤性、力学性能。研究结果表明:在CNT质量分数为0.18％、导电剂质量分数为2％时,制得导电PET纤维的体积比电阻为3.86×108 Ω·cm,且力学性能较纯PET下降不大。通过浸泡水洗,其体积比电阻基本不变,说明其具有优良、比较稳定的导电性和耐洗涤性。对纤维导电机理做了初步探讨。     

CPE在PE／EVA／CB型PTC材料体系中的作用

本文以聚乙烯／乙烯－醋酸乙烯酯共聚物／炭黑（PE／EVA／CB）体系为研究对象，采用熔融共混挤出成型制样的方法，探讨了氯化聚乙烯（CPE）在体系中的稳定作用，结果表明，在体系中加入CPE可以起到相容剂的作用，能大大改善炭黑在聚合物中的分散，提高材料体系中各相间的结构稳定性，降低材料体系的电阻率，使炭黑和聚合物间的复合更为均一，从而可以在一定程度上提高材料的导电性及稳定性。并在体系中加入2．5％（质量百分比）的CPE时即可收到明显效果。     

PET/PBT共混导电复合材料的研究

采用DSC（差示扫描量热法）对PET／PBT合金的相容性进行了研究，探讨了导电炭黑加入量对PET／PBT合金的导电性能与力学性能的影响。结果表明，PET／PBT共混物在非晶区相容而在晶区不相容或部分相容，导电炭黑填充PET／PBT合金的渗流阈值为15％，导电炭黑的填充对合金的力学性能有负面的影响。     

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。     

Percolation threshold of electrically conductive master batch for polyester fibers application

In the case of the electrically conductive master batch (ECMB) for fibers application, higher filler content required to produce adequate conductivity can be accompanied by a reduction in spinnability and mechanical property of final fibers. To minimize these problems, ECMB with the character of lower percolation threshold was designed in this article. Carbon black (CB) was treated by titanate coupling agent. Polymer blend poly(ethylene terephthalate) (PET)/polyethylene(PE) was used as matrix instead of individual polymer matrix. The effects of titanate coupling agent treatment and the composition of polymer blend on the properties of ECMB have been discussed. FTIR and laser particle size distribution analyzer were employed to study the CB. Solubility tests and positive temperature effect peak were used to verify the distribution of CB in the polymer blend. These results showed that CB treated with 2 wt % titanate coupling agent and PET/PE polymer blend with the weight ratio of 60/40 appear to be an effective way to design the ECMB with a low percolation threshold. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4144–4148, 2006     

PET/PE/CB导电母料的研制

采用分离喂料技术在聚对苯二甲酸乙二酯(PET)/聚乙烯(PE)共混物中加入导电炭黑(CB),通过布斯往复式脉动挤出机熔融共混、挤出造粒,制备了综合性能较好的纤维级PET/PE/CB导电母料。研究发现,以PET/PE不相容共混物代替PET作母料的基体树脂,能以较低的CB用量获得较好的导电性能;CB的质量分数为15%时,母料的体积电阻率随PET用量的增加呈先减小后增大的趋势,在PET与PE的质量比为60∶40时,母料的体积电阻率最低。     

The role of the surface microstructure of the microfibrils in an electrically conductive microfibrillar carbon black/poly(ethylene terephthalate)/polyethylene composite

Carbon black (CB) loading greatly affects the in-situ fibrillation of CB/poly (ethylene terephthalate) (PET) compound in a polyethylene (PE) matrix during melt mixing, slit die extrusion and hot stretching. CB/PET/PE composites with lower CB loadings display well-defined CB/PET microfibrils in which all the CB particles are localized. The surface microstructure (mainly amount and distribution of CB particles) of in-situ CB/PET microfibrils is a key factor determining the electrical conductivity of the microfibrillar composite, and is dominated by the CB content in the in-situ CB/PET microfibrils. With low CB content, there are hardly any CB particles on the surface of the CB/PET microfibril. The volume resistivity of in-situ microfibrillar composite remains high. With higher CB loading, the number of CB particles on the surfaces of the microfibrils increases significantly. Above a critical value (maximum packing fraction), the microfibril network was connected by electrically conductive contact points and thus was able to sustain electron transmission in the whole system. As a result, the volume resistivity of in-situ microfibrillar CB/PET/PE composite dropped sharply and percolation occurred.     

碳黑系聚酯导电母粒的研究

分别将未处理的碳黑和经钛酸酯偶联剂处理后的碳黑与聚酯切片混合后,经双螺杆熔融共混,制备了纤维级导电母粒。研究了钛酸酯偶联剂的作用机理和钛酸酯偶联剂用量对母粒导电性能和流变性能及所得纤维力学性能的影响。结果表明:偶联剂的加入起到了内增塑的作用,降低了母粒的表观黏度,适当的偶联剂用量可用于设计和制备具有低突增界限浓度的导电母粒。     

Enhanced Electrically Conductive Polypropylene/Nano Carbon Black Composite

In this work, a porous polypropylene (PP)/nano carbon black (CB) composite was facilely fabricated via immiscible co-continuous polymer blend and subsequent dissolution process. The porous structure was generated from co-continuous polymer blend, which was exploited as the substrate for depositing nano CB. The interconnected micro pores of the co-continuous polymer blend and nano pores derived from agglomerated CB resulted in a significant enhancement of conductivity. Comparing with the conventional carbon composite obtained through dual-percolation method, the electrical conductivity of PP/CB composite increased 10 orders of magnitude with CB loading ranged from 1 wt% to 5 wt%. Moreover, it was found that the percolation threshold of PP/CB composite decreased nearly 80% compared with that of as-mixed sample. The enhanced conductivity and much lower percolation make this novel method a potential way for fabricating porous conductive materials for advanced application.     

The Resistivity Response of an Anisotropically Conductive Polymer Composite with in-situ Conductive Microfibrils During Cooling

The resistivity response of anisotropically conductive polymer composite (ACPC) with carbon black (CB) particles selectively localizing at the surfaces of aligned polyethylene terephthalate (PET) microfibrils was investigated during cooling from 180°C in the parallel and perpendicular directions. The ACPC exhibited a cooling positive temperature coefficient (PTC) around the crystallization temperature of polyethylene (PE) matrix. With the increase of CB loading, the cooling PTC effect decreased gradually. When the ACPC experienced isothermal annealing, the aligned microfibrils disordered to form more conductive pathways. The increase of annealing time caused the gradual attenuation of the cooling PTC effect in both directions.     

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     

Structural variations and morphological features of polyethylene/carbon black conductive composites after processing in an internal mixer

Polyethylene (PE) composites filled with carbon black (CB) were prepared using an internal mixer. Several analytical techniques, including rheometry, gel permeation chromatography, electrical conductivity measurements, differential scanning calorimetry, wide‐angle X‐ray diffraction, and transmission electron microscopy (TEM), were used to reveal the structural variations, thermal degradation, morphological features, and crystallization of the PE/CB conductive composites. It was found that the PE polymer chains were degraded, forming long‐chain branching structures after over 30 min of internal mixing. The electrical conduction of the PE/CB composites was determined by the filler content and distribution. The electrical percolation threshold of the PE/CB composites was determined to be between 20 and 30 wt %. The addition of CB had no significant influence on the crystallinity of the PE/CB composites. In contrast, the electron‐beam radiation dose had a significant effect on crystallinity. TEM micrographs of the PE/CB composites exhibit a random four‐phase morphology, including PE lamellae, PE amorphous, CB particles, and voids at the PE/CB interface. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1038‐1046, 2013     

Manipulating the conductivity of carbon‐black‐filled immiscible polymer composites by insulating nanoparticles

The conductivity of an immiscible polymer blend system, microfibrillar conductive poly(ethylene terephthalate) (PET)/polyethylene (PE) composite (MCPC) containing carbon black (CB), was changed by the addition of insulating CaCO₃ nanoparticles. In MCPC, the PET forms microfibrils during processing and PE forms the matrix. The CB particles are selectively localized in the PET microfibrils. When the insulating CaCO₃ nanoparticles are added, they substitute for some of the conductive CB particles and obstruct the electron paths. As a result, the resistivity of the MCPC can be tailored depending on the insulating filler content. The resistivity‐insulating filler content curve displays a sluggish postpercolation region (the region immediately following the percolation region and in front of the equilibrium flat of the resistivity‐filler content curve), suggesting that the MCPC in the postpercolation region possesses an enhanced manufacturing reproducibility and a widened processing window. These features are of crucial importance in making sensor materials. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.     

Electrically conductive carbon black (CB) filled in situ microfibrillar poly(ethylene terephthalate) (PET)/polyethylene (PE) composite with a selective CB distribution

In the present study, it was attempted to fabricate a new conductive carbon black (CB) filled poly(ethylene terephthalate) (PET)/polyethylene (PE) in situ microfibrillar composite with a lower percolation threshold through selectively localizing CB particles in the surfaces of the PET microfibrils. The CB particles were first mixed with PE matrix, and then PET was added into CB/PE compound. Subsequently, the CB/PET/PE composite was subjected to a slit die extrusion, hot stretch and quenching process to generate in situ PET microfibrils, in which CB particles moved to the surfaces of the PET microfibrils simultaneously. The morphological observation showed that the PET phases formed well-defined microfibrils, and CB particles did overwhelmingly localize in the surfaces of the PET microfibrils, which led to a very low percolation threshold, i.e., 3.8 vol%, and a good conductivity. The conductive network was built by the contact and overlapping of the CB particles coated PET microfibrils. In addition, the CB particles remaining in the PE matrix also contributed to the conductive paths, especially for the high CB loading filled microfibrillar composites. Because of the complexity of the distribution of CB particles, a high critical resistance exponent t (t = 6.4) exists in this conductive composite. To reveal the possibility of the migration of CB particles from PE to PET, the morphology of the CB/PET/PE composite mixed for different times was examined. It was found that, depending on the mixing time, the CB particles gradually migrated from the PE matrix to the surfaces at first, and then to the center of the PET phases. The preferable distribution of CB particles was originated from several factors including interfacial tension, viscosity, molecule polarity, and mixing process. Furthermore, during the mixing process of the CB/PET/PE composite, the migration of CB particles to PET phase from PE matrix led to the increase of both the viscosity ratio of the dispersed phase to the matrix and the volume of the dispersed phases, thus resulting in larger dispersed CB/PET composite phase particles.