高弹性高导电稳定性炭黑/碳管/硅橡胶复合材料的设计与制备  

Design and preparation of carbon black/carbon nanotubes/silicone elastomer composites with high elasticity and high electrical conductivity stability

作　　者：宁南英[1,2] 刘苏亭 赵柔 邹华 于冰[1,2] 田明 张立群[1,2] Nanying Ning;Suting Liu;Rou Zhao;Hua Zou;Bing Yu;Ming Tian;Liqun Zhang(State Key Laboratory of Organic-Inorganic Composites,Beijing University of Chemical Technology,Beijing 100029,China;Key Laboratory of Carbon Fiber and Functional Polymers,Ministry of Education,Beijing University of Chemical Technology,Beijing 100029,China;Department of Chemical Engineering,Weifang Vocational College,Weifang 262737,China)

机构地区：[1]北京化工大学有机无机复合材料国家重点实验室,北京100029 [2]北京化工大学碳纤维及功能高分子教育部重点实验室,北京100029 [3]潍坊职业学院化学工程学院,潍坊262737

出　　处：《科学通报》2018年第34期3677-3686,共10页Chinese Science Bulletin

基　　金：国家重点基础研究发展计划(2015CB654700;2015CB654704);国家杰出青年科学基金(51525301);国家自然科学基金(51521062)资助

摘　　要：采用少量炭黑(CB)和少量碳纳米管(CNTs)并用,通过调控CB和CNTs在甲基乙烯基硅橡胶(PMVS)基体中的网络结构,成功制备了低导电填料下高弹性、高导电性、高循环拉伸导电稳定性的PMVS-CB-CNTs导电橡胶复合材料.当1.8%(体积百分比,下同)CB和1.2%CNTs并用时,复合材料体积电阻率降低至271Ωcm, 30%拉伸应变下的体积电阻率(R/R0)为2.1,10次循环拉伸再回复后其R/R_0低至1.3.CNTs是原位生长在层状双氢氧化物表面而制备的碳管阵列(CNTA),其与橡胶混炼加工时易于解离成单根分散碳管,不易缠结,且其高长径比有利于低填料量下获得高导电性;而CB的各向同性能够使复合材料拉伸回复后形成新的导电通路.由于所用CNTs具有纳米弹簧效应,复合材料保持了良好的弹性和柔顺性.进一步研究了复合材料在拉伸应变过程中的电导性的变化和循环拉伸导电稳定性,以及拉伸应变下导电网络结构变化和拉伸前后的填料网络结构变化,探明了复合材料导电网络结构与导电性及导电稳定性的关系.结果表明,低含量CB和CNTs可在橡胶基体中形成较强的双导电网络结构;拉伸时,CNTs作为桥梁连接单个的CB粒子及其聚集体,导电网络破坏较小;经循环拉伸再回复后,CB和CNTs又可回复形成较强的双导电网络结构,因此该复合材料电导性较高,且单次拉伸和循环拉伸导电稳定性均较好.Conductive elastomer composites(CECs) with high elasticity, flexibility and sealability of elastomers and the high electrical conductivity of conductive fillers have been widely used in electromagnetic interference shielding, microwave absorpting, stretchable electronics and sensors. To achieve high electrical conductivity, the commonly used fillers are metal powers, metal-coated inorganic particles and carbon black(CB). High filler content is usually required to effectively improve the conductivity, resulting in low elasticity, low flexibility, and poor processability, all of which limit the applications of CECs. Earlier works reported the synergistic effect of two kinds of fillers with different geometrical dimensions, among which CB and carbon nanotubes(CNTs) are two promising candidate that have been widely studied. However, CNTs are easily entangled and aggregated in elastomer matrix with low viscosity, resulting in unsatisfactory conductivity(mostly 104–105 Ω cm). Moreover, little attention has been paid on CECs with high elasticity, high electrical conductivity stability filled with low filler contents(low cost) for stretchable electronics and strain sensors. The relationship between conductive network and electrical conductivity as well as electrical conductivity stability is still not clear. In this study, we designed and prepared CB/CNTs/polymethylvinylsiloxane(PMVS) composites with good elasticity, high electrical conductivity and good electrical conductivity stability by tailoring the filler network structure of the composites with a low content of CB and CNTs in PMVS matrix. The composite with 1.8 vol% of CNTs and 1.2 vol% of CB showed high elasticity, low volume resistivity(271 Ω cm), and high electrical conductivity stability. CNTs used in this study were carbon nanotube arrays(CNTA) that were in situ synthesized on single-layered double hydroxide(LDH) nanosheets by chemical vapor deposition method. The negatively charged CNTs with a loose structure showed no physical entanglement, which can be

关 键 词：导电橡胶复合材料 导电网络结构 导电性 导电稳定性 碳纳米管 炭黑 

分 类 号：TB332[一般工业技术—材料科学与工程]