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在恒温(170～190℃)热处理过程中,多壁碳纳米管(MWCNTs)填充聚苯乙烯(PS)熔体发生动态模量逾渗(DMP)行为,且该行为服从时-温叠加(TTS)原理.MWCNTs体积分数(φ)低于逾渗阈值(φc)时,填充熔体在恒温热处理过程中保持类液行为,热处理对MWCNTs分散状态无显著影响,动态储能模量(G’)与动态损耗模量(G″)活化能(EG’与EG″)分别高于、低于PS黏流活化能(Eω),而与PS熔体恒频动态模量活化能相一致;φ>φc时,热处理促成MWCNTs进一步团聚,填充熔体在热处理过程中发生类液-类固转变,EG’与EG″均低于Eω,而动态逾渗时间活化能(Et’与Et″)显著高于Eω且随φ增高而增大.在逾渗转变区,EG’与EG″发生不连续变化.PS/MWCNTs复合体系的恒温依时DMP行为与MWCNTs聚集所导致的三维弹性网络的形成密切相关,PS大分子终端松弛不是决定DMP的关键因素.
The dynamic modulus percolation (DMP) behavior of polystyrene (PS) melts filled with multi-walled carbon nanotubes (MWCNTs) was observed at a constant temperature (170-190 ℃) ) Principle.When the volume fraction (φ) of MWCNTs is below the percolation threshold (φc), the filling liquid retains the liquid-like behavior during the isothermal heat treatment and the heat treatment has no significant effect on the dispersion of MWCNTs. The dynamic storage modulus (G ’ And EG (EG ’) and EG (EG’) were higher than and lower than the activation energies of PS viscous flow (Eω), respectively, but consistent with the constant modulus activation energies of PS melt; φ> At φc, the MWCNTs were further agglomerated by heat treatment, and the liquid-solid-like transformation occurred during the heat treatment. EG ’and EG’ were lower than Eω, while the dynamic percolation activation energies (Et and Et) And increases with the increase of φ. In the percolation transformation zone, EG ’and EG "discontinuously change.The isothermal DMP behavior of PS / MWCNTs composites is closely related to the formation of three-dimensional elastic network caused by the aggregation of MWCNTs , PS macromolecule terminal relaxation is not the key factor that determines DMP.