多壁碳纳米管填充聚苯乙烯复合体系的动态流变特性  

DYNAMIC RHEOLOGICAL PROPERTIES OF POLYSTYRENE/MULTI-WALLED CARBON NANOTUBES COMPOSITES

作　　者：管爱枝[1,2] 宋义虎[1] 谭业强[1] 郑强[1] 

机构地区：[1]高分子合成与功能构造教育部重点实验室浙江大学高分子科学与工程学系,杭州310027 [2]浙江科技学院机械与汽车工程学院,杭州310023

出　　处：《高分子学报》2011年第2期224-229,共6页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号20774085)资助项目

摘　　要：应用两相模型探讨多壁碳纳米管(MWCNTs)填充聚苯乙烯(PS)复合体系的动态流变特性.结果表明,体系线性黏弹行为与PS本体的应变放大效应及MWCNTs填料相的弛豫密切相关.在不同温度下,应变放大因子(Af)随MWCNTs体积分数(φ)的变化规律符合扩散控制的粒子串聚集(CCA)模型.φ<0.020时,MWCNTs分散较均匀,温度变化对Af-φ关系无显著影响.φ较高时,MWCNTs形成聚集体,Af随温度升高而显著降低.填料相特征动态模量(G′f1与G″f0)随温度的变化符合Arrhenius关系,且活化能(E′a与E″a)在φ=0.025附近发生不连续变化,说明温度对均匀分散的MWCNTs(φ<0.020)与MWCNTs逾渗网络(φ>0.025)的黏弹行为具有不同的影响规律.复合体系黏弹逾渗现象与导电逾渗密切相关,导电逾渗转变上限浓度范围为φ=0.020～0.025.Dynamic rheological properties of multi-walled carbon nanotubes（MWCNTs） filled polystyrene（PS） melt were investigated in relation to a two phase model proposed by authors.The linear viscoelastic behavior of the composites is related to the strain amplification effect of the bulky polymer phase far away from the filler inclusions and the relaxation of the filler phase.Dependence of strain amplification factor（Af） on MWCNTs volume fraction（φ） at different temperatures accords with the diffusion-controlled cluster-cluster aggregation（CCA） model.At φ 0.020,MWCNTs are rather homogeneously dispersed in the matrix,and no remarkable change appears in the relation between Af and φ with increasing temperature.Af decreases obviously with increasing temperature at higher φ where MWCNTs form cluster aggregates.Characteristic dynamic moduli（G′f1 and G″f0） of the filler phase as a function of temperature follow Arrhenius law with the corresponding activation energies（E′a and E″a） varying discontinuously at φ = 0.025,suggesting that the temperature dependence of viscoelasticity of the homogeneously dispersed MWCNTs at φ 0.020 is considerably different from that of the MWCNTs percolation network at φ 0.025.The viscoelastic percolation is closely related to the conduction percolation,and the discontinuous variations of activation energies in  range from 0.020 to 0.025 appear in the vicinity of the upper limit of the conduction percolation threshold.The dispersion of MWCNTs in the matrix has been verified in transmission electron microscope（TEM） observation.

关 键 词：两相模型 多壁碳纳米管 聚苯乙烯 复合体系 动态流变特性 逾渗 

分 类 号：TB383.1[一般工业技术—材料科学与工程]