A synergistic functionalization strategy for polycarbonate-based CFRTPs: enhanced adhesion and accelerated depolymerization

• Selective amine functionalization of PC polymers using two methods (ACC reaction and ICP reaction) for carbon fiber reinforced thermoplastics. • Identify the mechanism of how nitrogen atoms are functionalized onto the surface of PC films. • Fabrication of CFRTP with significantly improved interfacial bonding using functionalized PC films. • A closed loop cycle system was designed by rapidly recycling CFRTP using the ACC reaction. Polycarbonate (PC) is a widely utilized engineering thermoplastic in automotive, aerospace, and electronic applications due to its exceptional toughness, transparency, thermal stability, and dimensional integrity. However, its high molecular weight and resultant viscosity hinder resin impregnation in composite manufacturing, and its non-biodegradability raises sustainability concerns. To address these limitations, we developed a dual-surface functionalization strategy for PC films by combining chemoselective amination and inductively coupled plasma (ICP) treatment. This approach introduced high-density amine groups both on the surface and within the bulk of PC films, enhancing their surface characteristics as evidenced by a 35 % reduction in contact angle, a 122 % increase in surface energy, and a 16 % increase in surface nitrogen content. These modifications resulted in a 53 % enhancement in interlaminar shear strength and more uniform resin impregnation with fewer voids in carbon fiber-reinforced thermoplastic composites (CFRTPs). Furthermore, the modified PC enabled rapid and selective depolymerization under mild conditions (80 °C, 12h), allowing for clean separation of matrix and carbon fibers with full retention of fiber integrity. This work demonstrates a scalable and sustainable route to high-performance CFRTPs by leveraging the intrinsic advantages of PC in conjunction with precise surface modification chemistry.