Conductive thermoplastic vulcanizates (TPVs) based on polypropylene (PP)/ethylene-propylene-diene rubber (EPDM) blend: From strain sensor to highly stretchable conductor

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• 作者：Li-Feng Ma ; Rui-Ying Bao ; ^{rybao@scu.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Rui Dou ; Shao-Di Zheng ; Zheng-Ying Liu ; Rui-Yan Zhang ; Ming-Bo Yang ; Wei Yang ; ^{weiyang@scu.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Carbon nanotubes ; Polymer-matrix composites (PMCs) ; Electrical properties ; Scanning/transmission electron microscopy (STEM) ; X-ray diffraction (XRD)
• 刊名：Composites Science and Technology
• 出版年：2016
• 出版时间：18 May 2016
• 年：2016
• 卷：128
• 期：Complete
• 页码：176-184
• 全文大小：2763 K

文摘

Conductive elastomeric materials of multi-walled carbon nanotube (MWCNT) filled thermoplastic vulcanizate (TPV) based on polypropylene (PP)/ethylene-propylene-diene rubber (EPDM) blends were fabricated via different processing procedures, i.e., one-step and two-step methods, to control strain sensitivity aiming at applications from strain sensors to stretchable conductors. The phase size of cross-linked EPDM could be effectively tuned and the average diameter of EPDM particles was 550 nm for one-step TPV and 230 μm for two-step TPV. Uniform dispersion of MWCNTs in two-step TPV and serious aggregations of MWCNTs in one-step TPV were observed. Both TPVs showed excellent strain-resistance repeatability for 50 tensile and recovery cycles. The one-step-TPV showed a potential to be used as strain sensor due to a high gauge factor (GF) of 1004 at a strain of 100%, while the resistance for the two-step TPV composite was independent with strain even at a strain of 200%, resulting in a stretchable conductor with excellent resistance memory effect. The different strain sensitivity can be explained by the orientation of PP matrix. Moreover, the two-step TPV showed much lower electrical conductivity percolation threshold, 0.65 wt.%. This work provided a simple route to tune the strain sensitivity of MWCNTs filled TPVs based on PP/EPDM blends for applications from strain sensors to highly stretchable conductor through different processing procedures to control the morphologies and MWCNT dispersion.