Polyamide-6-Based Thermoplastic Elastomers and Their Filaments with Improved Thermomechanical Performance Enabled by Enhanced Hydrogen Bonding Interactions

Abstract

Enhancing the glass transition temperature of the hard phase (T g-HS ) and the tensile strength of PA6-based thermoplastic elastomers (TPAEs) has been a long-standing challenge, significantly restricting their application in textiles. In this study, this issue was effectively addressed by incorporating pphenylenediamine (PPD) into the molecular chains, which induces enhanced hydrogen bonding interactions in TPAEs. Consequently, the prepared PPDmodified TPAEs (PPD-TPAEs) demonstrated a well-defined nanophaseseparated morphology and a T g-HS of 48.2 °C, which is more than 5 °C higher than that of TPAEs with the same soft segment weight concentrations (C SS ). Additionally, the T g-HS increased with higher C SS values due to the augmented hydrogen bonding interactions in PPD-TPAEs. The tensile strength and elongation at break of PPD-TPAEs were over 1.9 and 2.6 times greater, respectively, than those of TPAEs with the same C SS value. Notably, filaments produced from molten PPD-TPAEs with 44% soft segments (PPD-TPAE-40) exhibited thermomechanical performance comparable to Spandex, underscoring their potential application in the textile industry.