Strain sensing, electrical and mechanical properties of polycarbonate/multiwall carbon nanotube monofilament fibers fabricated by melt spinning. (15th January 2016)

• Record Type: Journal Article
• Authors: Bautista-Quijano, José Roberto; Pötschke, Petra; Brünig, Harald; Heinrich, Gert
• Is Part Of: Polymer. Volume 82(2015)
• Page Start: 181
• Page End: 189
• Publication Date: 2016-01-15
• Subjects: Carbon nanotubes -- Polymer fibers -- Piezoresistivity -- Strain sensing -- Melt spinning; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2015.11.030
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Polycarbonate (PC)/multiwall carbon nanotube (MWCNT)/composites were prepared by melt mixing and subsequently melt spun to monofilament fibers. Electrical, mechanical and piezoresistive (strain sensing) properties of the fibers were evaluated as a function of the MWCNT weight concentration, which was varied up to 6 wt%. After the incorporation of MWCNTs, a decrease in electrical resistivity of the fibers was found for MWCNT concentrations as low as 2 wt%. Furthermore, an important effect of the draw down ratio (DDR) on the electrical properties of the fibers was observed. While the electrical percolation threshold (φc ) for the bulk material was <1 wt% and ∼1 wt% for the undrawn-extruded rods, for the melt-spun fibers φc was found to be highly dependent on the DDR. Stiffness and offset yield stress of the MWCNT/PC fibers were increased starting with the addition of 1 wt% of MWCNTs. However, decreased spinnability was observed for fibers with MWCNT concentrations above 4 wt%. The coefficient that relates the electrical resistance changes to the mechanical strain (strain gage factor SGF ) was estimated for fibers with MWCNTs amounts that range from 3.5 to 6 wt%. The highest SGF ∼16 was found at 3.5 wt% and the lowest SGF ∼2.5 at 6 wt% MWCNT. Smart multifunctional textiles, made from such conductive fibers, have wide applications such as structural health monitoring, detection of gases and liquids, sensor arrays and flexible sensors. Graphical abstract: Highlights: Polycarbonate/CNT fibers were successfully melt-spun. Mechanical, electrical and piezoresistive properties were evaluated on the fibers. Enhanced mechanical and electrical properties were achieved starting at 1 wt% CNT. Increasing draw down ratio & lowering CNT wt% enhances the strain sensitivity. Gage factors (strain sensitivity) as high as 16 were obtained from the fibers.