A simple synthesis of supramolecular Polyamide12 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.