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研究了增容剂马来酸酐接枝聚乙烯(PE-g-MAH)、乙烯-醋酸乙烯酯(EVA)、苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)对高密度聚乙烯(PE-HD)/聚碳酸酯(PC)/炭黑(CB)复合材料导电性能的影响。结果表明,加入增容剂有利于增强复合材料的正温度系数(PTC)效应,其中嵌段共聚物SBS对复合材料PTC效应的改善效果相对较好,SBS含量为4%(质量分数,下同)时,复合材料的PTC强度最高,比未添加时提高了14.3%;接枝共聚物PE-g-MAH的加入对复合材料PTC效应的增强效果弱于SBS;无规共聚物EVA的加入对负温度系数(NTC)现象具有明显的抑制作用,使复合材料的NTC强度从0.3下降至0.08。 相似文献
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本文研究了炭黑填充线性低密度聚乙烯复合物的导电性与炭黑含量的关系,PTC强度与CB含量的关系,探讨了未交联与交联复合的PTC效应的热重复性和NTC效应。 相似文献
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炭黑粒子偶联处理的HDPE复合材料PTC性能研究 总被引:1,自引:0,他引:1
研究了以HDPE为基体,工业炭黑(CB)为导电粒子的高分子复合材料的PTC(正温度系数)导电行为。考察了炭黑及偶联剂种类、用量对高分子PTC导电材料性能的影响,并探讨了偶联接枝机理,从理论上对改性效果进行了分析。结果表明,对炭黑,尤其是槽法炭黑 表面处理可显著提高复合材料的电导率及减小NTC(负温度系数)效应;钛酸酯偶联剂具有最佳改性效果,可明显改善炭黑粒子分散状态,增强材料的PTC效应,其最佳用量为1%质量份。 相似文献
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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. 相似文献
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采用高结构导电炭黑(CB)Vxc—72与半晶聚合物高密度聚乙烯(HDPE)进行熔融共混,制备复合型导电高分子材料。研究了该复合体系中偶联处理、混炼时间、辐射及退火处理等工艺因素对其PTC(电阻—温度效应)性能的影响。结果表明,当辐照剂量为140—160kGy、炭黑非均匀分散且进行退火处理时复合体系具有最佳的PTC性能,但混炼时间过长、偶联处理均会使复合体系PTC强度降低。 相似文献
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偶联处理对HDPE/炭黑复合材料PTC性能的影响 总被引:11,自引:0,他引:11
以HDPE/工业炭黑(CB)复合材料为研究对象,考察了炭黑及偶联剂种类、用量对高分子PTC(正温度系数)导电材料性能的影响,并探讨了偶联接技机理,从理论上对改性效果进行了分析。结果表明,对炭黑(尤其是槽法炭黑)进行表面处理可显著提高复合材料的电导率,减小NTC(负温度系数)效应;钛酸配偶联剂具有最佳改性效果,可明显改善炭黑粒子分散状态,增强材料的PTC效应,其最佳用量为1%。 相似文献
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制备工艺对PTC复合材料阻温特性的影响 总被引:3,自引:0,他引:3
研究了密炼工艺对聚乙烯/炭黑复合材料室温电阻率及PTC强度的影响,针对一定配方找到了最佳密炼工艺条件。电子束辐照交联能有效消除NTC现象和提高材料的电性能循环稳定性,有助于制备低电阻率、高PTC强度并具有较好电性能循环稳定及热敏开关特性和电路保护元件。 相似文献
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The electrical‐resistivity/temperature behaviors of low‐density polyethylene (LDPE)/carbon black (CB) composites irradiated with 60Co γ rays were studied. The experimental results showed that the irradiated composites could be separated into insoluble crosslinking networks with CB (gel) and soluble components (sol) by solvent‐extraction techniques. When the sol of an irradiated LDPE/CB composite was extracted, the electrical conductivity of the system increased. The positive‐temperature‐coefficient (PTC) and negative‐temperature‐coefficient (NTC) intensities of the gels of the irradiated composites became extremely small and independent of the radiation dose. The sols and gels of the irradiated LDPE/CB composites, which had different thermal behaviors, played important roles in the appearances of the PTC and NTC effects. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 700–704, 2005 相似文献
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Several types of positive temperature coefficient (PTC) composites are prepared by using Ni and Au modified carbon black. The major aim of this work was the lowering of the room temperature resistivity of the composites by enhancement of electrical conduction of the CB particles by incorporating metallic particles. Investigations showed that the metal particles fill the cavities and surface defects of the CB and thus surface free area reduces after modification. Metallic particles also change the nature of the CB particles after modification. Several types of PTC composites were prepared by using modified and unmodified CB by several loading level of filler. Measuring electrical properties of the PTC samples showed that the Ni modified CB reduce room temperature resistivity to lower than that of PTC composites prepared by unmodified CB. PTC composites prepared by Au modified CBs showed very different properties compared to PTC composites prepared by Ni modified CB. Their resistivities were quite higher than the others showing a poor compatibility between the matrix and Au modified CB. The effect of thermal annealing also investigated on the electrical properties of the prepared composites. Room temperature resistivities reduced for most of the samples while PTC intensities increased after annealing. Theoretical bases are employed to discuss the room temperature resistivity and PTC behavior of the composites before and after annealing. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
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PE/炭黑导电复合体系正(电阻)温度系数 总被引:19,自引:1,他引:18
较系统地研究了以LDPE,HDPE,LLDPE等为基体,在各自临界组成区域掺混一同类型的炭黑对复合物正(电阻)温度系数(PTC)负(电阻)温度系数导电特性的影响。结果发现,不同类型的PE及炭黑种类的PTC特性曲线具有不同特征,通过对导电填料进行表面处理及对PE进行接技改性可以提高导电复合物的热电稳定性。 相似文献
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以炭黑(CB)为导电填料,高密度聚乙烯(PE–HD)为基体,有机蒙脱土(OMMT)为有机粒子,通过熔融共混法分别制备了PE–HD/CB与PE–HD/CB/OMMT导电复合材料,并研究了OMMT的加入对导电复合材料中CB分布的均一性及材料电性能的影响。研究发现,适当OMMT的加入可以改善CB在导电复合材料中的分布状态,在保持电性能的基础上降低导电复合材料的渗流阈值;当OMMT质量分数为3%时,PE–HD/CB/OMMT导电复合材料的渗流阈值为3.7%,与未添加OMMT的PE–HD/CB导电复合材料渗流阈值4.0%相比有所降低。在此基础上,选取PE–HD/CB导电复合材料(CB质量分数为5%)并测定其PTC强度为0.26;后加入质量分数为3%的OMMT,测得PE–HD/CB/OMMT导电复合材料(CB质量分数为5%)的PTC强度为0.79,后者有所提高。 相似文献