Significant enhancement of elasticity of PTT fiber via introduction of helical carbon nanotubes as nano ‘spring'

Due to its excellent physical properties and outstanding resilience, poly (trimethylene terephthalate) (PTT) fiber is widely used for daily clothing, work clothing, sportswear, and casual wear. However, in some special cases where both large elongation and quick recovery are required, PTT fiber still faces challenges. In this paper, one facile and novel approach to improve the elasticity of PTT fiber through introducing helical carbon nanotubes (HCNTs) as nano ‘spring’. PTT fiber containing modified HCNTs (PTTHf) was successfully prepared through melt spinning and heat drawing. After 100 cycles of stretching testing, the elastic recovery ratio of PTTHf was still high up to 96 % at fixed elongation of 10 %, which was 22 % higher than that of control PTT fiber (PTTf). More interestingly, the complete recovery time of PTTHf-1.0 at fixed elongation of 20 % was only 5 min, while that of PTTf soared to more than 30 min. The instantaneous recovery speed of PTTHf-1.0 was extraordinarily as high as 50 %/ms, while that of PTTf was only 1.8 %/ms, reflecting the effect of the ‘spring’ characteristics of HCNTs. • For the first time, elasticity of PTT fiber was improved simply via introduction of HCNTs as nano ‘spring'. • HCNTs significantly improved the elastic recovery ratio, elastic recovery speed and stability of PTT fiber. • The mechanism of the enhancement of elasticity of the PTT fiber was ascribed as the dragging effect of HCNTs to the PTT chains.