摘要
研究了低密度聚乙烯(LDPE)/乙烯-醋酸乙烯酯(EVA)/炭黑(CB)导电发泡材料在压力作用下的导电行为。结果表明,LDPE/EVA/CB导电泡沫材料的渗滤阈值为21.6%。炭黑质量分数在20%~23%范围内,材料的导电性能与泡孔结构最佳。在压缩实验中,材料表现电阻负压力系数效应(NPCR)与电阻正压力系数效应(PPCR)。在定应变循环压缩实验中,压缩频率f=0.01 Hz比f=0.25 Hz的电阻变化更稳定,说明高频压缩易对导电网络造成破坏。每周期的电阻曲线均呈'w'型,说明NPCR向PPCR转变的行为可逆,该变化被认为与基体的压缩与泡孔壁的拉伸变形有关,由此提出导电泡沫材料压-阻特性模型。
The piezoresistive properties of low-density polyethylene / ethylene-vinyl acetate / carbon black( LDPE /EVA / CB) conductive foam were studied. The result shows that the percolation threshold of LDPE / EVA / CB conductive foam is 21. 6%. The conductivity and cell structure are the best when the content of CB is between 20% and 23%. A behavior of negative pressure coefficient of resistance( NPCR) turning to positive pressure coefficient of resistance( PPCR) exists under pressure. The conductive network are easier damaged by high frequency compression because the resistance curves change more stable in f = 0. 01 Hz than in f = 0. 25 Hz. The behavior of NPCR turning to PPCR is reversible due to the resistance curves of each cycle showing a 'W'-type. It is believed that piezoresistive behaviors are involved in compression of material and tensile deformation of cell-wall. A piezoresistive model was proposed to explain the experimental results.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2014年第12期76-80,87,共6页
Polymer Materials Science & Engineering
基金
武汉市科技攻关项目(200710321090-18)
