A simple synthesis of supramolecular <scp>Polyamide12</scp> via solid‐state melt reaction and its interlaminar properties in Carbon Fiber Reinforced Thermoplastics

Abstract Despite the exceptional mechanical properties of epoxy‐based carbon fiber‐reinforced plastic (CFRP), its commercial potential is limited due to high production costs and manufacturing difficulties. As a promising alternative, thermoplastic‐based CFRP (CFRTP) offers simpler manufacturing, lower cost, and recyclability. This study presents a strategy to overcome challenges for CFRTP manufacturing by using a low molecular weight (MW) thermoplastic that forms high‐MW assemblies via dynamic molecular interactions. A quadruple hydrogen‐bonding unit (UPy)‐end functional polyamide (PA‐UPy) was synthesized by simple solid‐state melt reaction of powdered mixture of PA12 and UPy‐containing isocyanate. An increase in tensile properties was observed with an increase in crystallinity by the adoption of UPy moiety. The adoption of PA‐UPy in CFRTP, prepared by simply stacking the powder and CF fabric followed by hot pressing, enhanced the composite's tensile and interlaminar properties. Therefore, this process is proposed as a simple and effective method to improve the mechanical properties of CFRTP. Highlights Synthesis of PA‐UPy achieved via solid‐state melt reaction of PA and UPy. PA supramolecular structure boosts tensile strength and modulus of films and CFRTP. UPy‐NCO doubles the interlaminar shear strength of PA‐UPy‐based CFRTP.