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聚氯乙烯/炭黑导电复合体系的压阻行为 总被引:1,自引:0,他引:1
研究了聚氯乙烯/炭黑(PVC/CB)导电复合体系在单轴压力作用下的压阻行为,发现CB含量对电阻-机械响应具有显著的影响.当CB含量低于渗流阈值时,PVC/CB复合材料呈现PPC效应;而高于渗流阈值时,呈现NPC效应.在渗流阈值附近,单轴压缩可诱导NPC效应的出现,或者抑制PPC效应. 相似文献
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采用流变-导电行为同步测试方法,研究了等规聚丙烯(iPP)/炭黑(CB)复合体系的等温结晶行为,发现当CB体积含量φCB远高于渗流转变上限时,其体系的流变行为与导电性能均在某一特征时间处发生突变,电阻突变的特征时间短于动态储能模量(G′)或法向应力(FN)突变的特征时间,表明结晶诱导期存在CB粒子运动,促使CB粒子在晶粒尺寸增长期形成渗流网络;另一方面,与静态方法相比较,动态方法所测特征时间较短,表明动态方法对体系结晶结构变化的响应较静态方法更为灵敏. 相似文献
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Poly(ethylene terephthalate)(PET)/carbon black(CB) composite fibers with improved mechanical properties in tensile modulus and tensile strength are prepared by eletrospinning. Stable dispersions suitable for electrospinning are obtained by dispersing melt pre-compounded PET/CB composites in hexafluoroisopropanol. The fiber morphology and CB dispersion are investigated by FESEM and TEM. The addition of CB has no obvious effect on fiber diameter, and the average fiber diameters for all the samples are around 2-3 μm. CB in the fibers is in the form of submicron-sized clusters. The thermal properties of the PET/CB composite fibers are evaluated by DSC, showing almost unchanged melting temperature and crystallinity. Uniaxial tensile tests are used to measure the mechanical properties of the PET/CB composite fiber mats. The fiber mats containing 1 wt%-8.5 wt% CB have significantly improved tensile modulus compared to neat PET fiber mat, showing reinforcing effect of CB. The electrical conductivity of the fiber mats has also been tested. 相似文献
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通过调节氧化镉与炭黑之间的界面实现了高效电化学二氧化碳还原. 不同氧化镉和炭黑含量的 CdO/CB复合材料利用超声处理方法制备. 采用X射线衍射、 X射线光电子能谱和透射电子显微镜对所得复合材料进行表征, 揭示了其结构组成和形貌. 用H型电解池对CdO/CB复合材料电催化二氧化碳还原的性能进行测试发现, CdO质量分数为20%的CdO/CB 可在-1.0 V(vs. RHE)电位下获得高达92.7%的总法拉第效率, 而纯CdO在相同条件下的法拉第效率仅为69.5%. CO的法拉第效率最高可达87.4%. 进一步的对比实验和动力学研究结果表明, CdO/CB具有更高的电催化CO2还原性能源于复合材料中氧化镉与炭黑之间的界面和高接触面积. 此外, CdO/CB可在至少10 h的二氧化碳电还原反应中保持稳定的CO法拉第效率. 相似文献
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乙烯类聚合物-炭黑复合物的PTC效应 总被引:2,自引:0,他引:2
本文以低密度聚乙烯(LDPE)和乙烯-醋酸乙烯酯共聚物(EVA)为基材,炭黑(CB)为导电微粒,探讨了聚合物-炭黑复合物的结构对正温度系数效应(PTC)增强与减弱的影响和炭黑含量与PTC效应的关系以及交联结构对PTC现象的稳定作用. 相似文献
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纳米微晶纤维素对炭黑补强天然橡胶力学性能和动态性能的影响 总被引:3,自引:0,他引:3
采用酸水解工业微晶纤维素(MCC)制备纳米微晶纤维素(NCC),将其与天然胶乳共凝沉,混炼时加入炭黑(CB),制备了天然橡胶(NR)/NCC/CB复合材料,研究了NR/NCC/CB和NR/NCC/CB/RH(间苯二酚-六亚甲基四胺络合物)复合材料的力学性能和动态性能,并与NR/CB体系的性能进行对比.结果表明NCC可以均匀分散在天然橡胶基体中,且依拉伸方向取向,随着NCC替代炭黑的份数增加,Payne效应减弱,说明NCC本身并不构成强的填料网络,NR/NCC/CB与NR/CB比较,前者整体的网络化程度减弱,体系的损耗因子变化不大,NCC的加入改善了NR/CB的力学性能和抗屈挠龟裂性能,降低压缩疲劳温升和压缩永久形变,当NCC取代5~20 phr CB后,仍然保持高耐磨炭黑补强天然橡胶的耐磨耗性能.动态力学性能显示NR/NCC/CB的玻璃化转变温度较NR/CB变化不大,0℃的tanδ略有下降的同时60℃的tanδ明显降低.NR/NCC/CB/RH体系的Payne效应较NR/NCC/CB明显减弱,力学性能、抗屈挠龟裂性能和耐磨耗性能进一步改善,体系的压缩疲劳温升和压缩永久形变更小. 相似文献
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低剪切混合方法制备炭黑/聚丙烯纳米复合材料及其电性能研究 总被引:2,自引:0,他引:2
采用一种在低剪切应力场下纳米复合材料的加工方法,制备得到纳米炭黑(CB)粒子在聚丙烯(PP)中以纳米尺度分散的聚合物导电复合材料.扫描电镜观察表明CB粒子在纳米复合材料中以纳米尺度存在,并均匀的分布在PP基体中.电性能测试发现,通过这种低剪切混合方法得到的纳米复合材料具有非常低的导电逾渗阈值(vc=2.49vol%)和较高的临界电阻指数(t=5.82),很大的偏离了普适逾渗理论.基于隧道逾渗模型对体系的电导率进行了模拟,并对CB的分散状态与导电网络的关系进行了分析.发现当纳米CB粒子以纳米尺度分散于基体中时,并不遵从接触导电机理,而是隧道逾渗机理在CB/PP纳米复合材料中起主导作用. 相似文献
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Current-voltage electrical behavior of in situ microfibrillar carbon black (CB)/poly(ethylene terephthalate) (PET)/polyethylene (PE) (m-CB/PET/PE) composites with various CB concentrations at ambient temperatures was studied under a direct-current electric field. The current-voltage (I-V) curves exhibited nonlinearity beyond a critical value of voltage. The dynamic random resistor network (DRRN) model was adopted to semi-qualitatively explain the nonlinear conduction behavior of m-CB/PET/PE composites. Macroscopic nonlinearity originated from the interfacial interactions between CB/PET micro fibrils and additional conduction channels. Combined with the special conductive networks, an illustration was proposed to interpret the nonlinear I-V characteristics by a field emission or tunneling mechanism between CB particles in the CB/PET microfibers intersections. 相似文献
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电响应聚合物薄膜的表面图案化 总被引:9,自引:0,他引:9
研究了炭黑(CB)和石墨(GP)填充高密度聚乙烯(HDPE)复合体系的动态流变行为.发现高填料含量时出现似固体行为,并认为它归因于无机粒子网络逾渗结构的形成.在相同聚合物基体条件下,粒子种类和粒子几何参数(粒子形状、大小、粒径分布)对低频区域流变行为、流变参数的逾渗行为和逾渗阈值(φc)有决定性影响,且种类的影响相比于粒子几何参数更为显著.此外,高表面活性及高比表面积(大径厚比、小尺寸)粒子填充体系具有较低的φc. 相似文献
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研究了炭黑(CB)和石墨(GP)填充高密度聚乙烯(HDPE)复合体系的动态流变行为.发现高填料含量时出现似固体行为,并认为它归因于无机粒子网络逾渗结构的形成.在相同聚合物基体条件下,粒子种类和粒子几何参数(粒子形状、大小、粒径分布)对低频区域流变行为、流变参数的逾渗行为和逾渗阈值(φc)有决定性影响,且种类的影响相比于粒子几何参数更为显著.此外,高表面活性及高比表面积(大径厚比、小尺寸)粒子填充体系具有较低的φc. 相似文献
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Morphology and performance of styrene butadiene rubber filled with modified graphite nanoplatelet and carbon black 下载免费PDF全文
In our work, effects of 2‐mercapto‐1‐methylimidazole modified graphite nanoplatelet (MMI–GN) and carbon black (CB) on static and dynamic mechanical properties of styrene butadiene rubber (SBR) composites were studied. MMI–GN is synthesized by ball‐mill process, and the result reveals that π–π interactions existed between MMI and GN. The results demonstrate that the static and dynamic mechanical performances of SBR/CB/MMI–GN composites are significantly improved over these of SBR/CB and SBR/CB/GN composites. Compared with SBR/CB, the tensile strength, tear strength, and modulus at 300% elongation of SBR/CB/MMI–GN–3 are greatly improved by 45%, 27%, and 4%, respectively. And the rolling resistance of SBR/CB/MMI–GN–3 is reduced by 3.7% with remaining almost unchanged in the wet grip property. The superiority of MMI–GN in the enhancement for the overall performance of SBR/CB composites is attributed to the well dispersion of GN throughout the SBR matrix and the enhanced interfacial interactions between GN and the SBR matrix. This work might expedite synthesis of the graphite‐based materials for enhancing rubber composites, and enlarge the potential applications of modified graphite to fabricate the high‐performance rubber composites. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Introduction The positive temperature coefficient(PTC) effect is characterized by an increase of resistivity with an elevated temperature.The PTC effect of carbon black(CB) filled polymers is useful for self-regulation heaters,over-current protectors,sensors,etc.Much work has been done on the PTC effect of the carbon black filled crystalline polymer composite[1-4],whereas carbon black filled amorphous polymers have not drawn researchers much attention because the PTC effect in these composites is small or cannot be detected[5-7].In this work,the influence of γ-ray irradiation on the PTC effect of CB filled amorphous ethylene-propylene-diene terpolymer(EPDM) composites was studied. 相似文献
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聚乙烯炭黑复合材料导电逾渗的蒙脱卡罗法研究 总被引:1,自引:0,他引:1
众所周知,在聚合物中加入导电粒子后可以制成导电复合材料,但是加入的导电组分的体积分数必须超过某个临界值.在这方面研究最多的体系就是聚乙烯-炭黑复合材料[1,2].当炭黑的体积分数低于该临界值时,复合材料的电导率极低. 相似文献
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