石墨烯改性导电胶的制备及导电机理研究

Study on preparation and conductive mechanism of graphene modified conductive adhesive

以环氧树脂(EP)为基体、聚苯胺为助剂、铜粉为导电填料和石墨烯为改性剂,采用共混法制备了高导电性、高粘接强度、低成本和固化后不易开裂的导电胶,并对其导电机理进行了分析。研究结果表明:铜粉作为导电填料,可使导电胶的成本大幅降低,当w(铜粉)=60%(相对于EP质量而言)时,导电胶的导电性能相对最佳(体积电阻率为4.14×10^(-3)Ω·cm)。石墨烯可进一步改善导电胶的导电性能,当w(石墨烯)=0.05%(相对于EP质量而言)时,导电胶的体积电阻率(2.78×10^(-3)Ω·cm)相对最低。石墨烯在胶体内形成类似钢筋骨架作用的网络结构,使填料之间连接更紧密,从而有效提高了导电胶的导电性能和力学性能,解决了导电胶固化后易开裂、韧性不足等难题。

With epoxy resin （EP） as matrix, polyaniline as additive, copper powder as conductive filler, and graphene as modifier, a conductive adhesive with some characteristics （such as high electrical conductivity, highbonding strength, low cost, and not easy to crack after curing） was prepared by blend method, and its conductive mechanism was analyzed. The research results showed that the copper powder as conductive filler can obviously reduce the cost of conductive adhesive, and the conductive adhesive had the relatively optimal electrical conductivity （volume resistivity at 4.14× 10-3 Ω· cm） when mass fraction of copper powder was 60% in EP. The graphene can further improve the electrical conductivity of conductive adhesive, and the conductive adhesive had the relatively lowest volume resistivity （2.78 ×10-3 Ω· m） when mass fraction of graphene was 0,05% in EP, The electrical conductivity and mechanical properties of conductive adhesive were effectively improved, and some problems （such as easy to crack after curing, and poor toughness） of conductive adhesive were solved because graphene in adhesive film form the network structure of similar steel skeleton, so the connection between filler and filler was more close.