PLA/Carbon Nanotubes Multifilament Yarns for Relative Humidity Textile Sensor

Abstract

Polylactide (PLA) was mixed with 4 wt.% of carbon nanotubes (CNTs) to produce electrical conductive multifilament yarns by melt spinning process for humidity detection. Thanks to a variation of electrical conductivity, this flexible sensor could detect the moisture presence. The introduction of plasticizer was necessary to ensure higher fluidity and drawability of the blend during the spinning process. The plasticizer modifies the crystallinity and the mechanical properties of the yarns. The effectiveness of this sensor (PLA/4 wt.% CNTs fibres) sensitive to humidity, is optimal when the spinning conditions are adapted. In this way, the temperature and the rate of the drawing roll were reduced. The influence of these parameters on the crystallinity, the mechanical properties and the sensitivity of the yarns were studied. Once the appropriate spinning conditions found, one humidity sensitive yarn was processed and the repeatability and efficient reversibility of its sensitivity were highlighted.