摘要
通过引入多功能化纳米颗粒从而赋予天然纤维增强高分子复合材料多功能性,使其具有传感性能,可原位感应外界环境变化。但制备多功能纳米复合材料通常需预先将纳米颗粒均匀分散在基体中,造成基体粘度大,难以工程化应用,同时需使用较大添加量才能达到渗透阈值。采用"染布法"以多壁碳纳米管(MWCNTs)悬浮液为"染料"对剑麻纤维(SF)表面进行改性,制备了多功能的剑麻纤维(MWCNTs-SF)及其环氧树脂基复合材料(MWCNTs-SF/EP)传感器。改性后剑麻纤维表面形成了一层连续的MWCNTs涂层。MWCNTs-SF的伏安特性曲线显示MWCNTs-MWCNTs和MWCNTs-电极之间形成了欧姆接触。MWCNTs-SF及MWCNTs-SF/EP均为负温度系数热敏电阻。在外界应力-应变的作用下,MWCNTs-SF及MWCNTs-SF/EP的电阻起初没有明显的变化,然后随应变线性增加,接着与应变成指数关系。MWCNTs-SF及MWCNTs-SF/EP对温度与应力-应变的响应特性不同是由于复合材料成型过程中的MWCNTs网络结构发生了变化。同时,随着MWCNTs改性次数增加,剑麻纤维布增强环氧树脂基复合材料的拉伸强度逐渐从37.6 MPa增大到46.7 MPa,弹性模量也相应增大。
Incorporating multi-functional nano-particles into natural fiber reinforced polymer composites can provide with the multi-functionality,making them possess sensor performance,which are capable of in-situ sensing the change of surrounding environment.However,it is realized by dispersing nano-particle into matrix,which normally leads to high viscosity of matrix,hindering its application and meanwhile high nano-particle loadings are needed to reach percolation threshold.Dip coating technology was used for the surface modification of sisal fibres(SF)with multi-walled carbon nanotubes(MWCNTs)dispersion as dye,the resulting MWCNTs modified sisal fibers(MWCNTs-SF)and their epoxy based composite(MWCNTs-SF/EP)sensors were prepared.A continuous and homogenous dispersed MWCNTs network coating forms on surface of MWCNTs-SF.The current versus voltage characteristic curve of MWCNTs-SF indicates the formation of ohmic contacts for MWCNTs-MWCNTs and MWCNTs-electrode.Both MWCNT-SF and MWCNTs-SF/EP are characterized by negative temperature coefficient thermistor.Under external strain-stress,the electrical resistance of MWCNTs-SF and MWCNTs-SF/EP exhibits nearly constant at very low strains,then increases linearly at intermediate strains,while an exponential correlation between electrical resistance and strain exists at higher strains.The different sensing characteristics for MWCNTs-SF and MWCNTs-SF/EP mostly relate to the MWCNTs network structure change during consolidation.The tensile strength of MWCNTs modified sisal fiber fabric reinforced epoxy based composite increases gradually from37.6 MPa to 46.7 MPa with increasing surface modification time,elastic modulus also increases accordingly.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2015年第3期625-631,共7页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(21201144)
福建省自然科学基金(2014J06021)
国家质检总局科技计划项目(2014IK254)
