High-temperature macro-molecular polymer composites for automotive applications: A critical review of sustainable matrices and performance

The growing demand for lightweight, thermally stable materials in the automotive industry has accelerated research on high-temperature polymer matrix composites (HT-PMCs) as alternatives to metals in harsh operating environments. This critical review evaluates the current state of advanced HT-PMCs, emphasizing macro-molecular design, processing strategies, automotive applications, and performance limitations. Thermoset systems such as polyimides, bismaleimides, and polybenzoxazines, together with thermoplastic matrices including PEEK, PPS, and recyclable blends, are examined for their mechanical properties, reinforcement compatibility, and thermal stability in the 200–400°C range. Recent advancements in sustainable matrices—particularly bio-based polyimides and recyclable thermoplastics—are highlighted, with comparative analyses of mechanical, thermal, and environmental performance to identify clear trends and research gaps. Case studies in powertrain components, electrification systems, brake assemblies, under-hood structures, and lightweight panels demonstrate weight reductions exceeding 30% alongside improved thermal management. Critical challenges such as moisture absorption, thermal-oxidative aging, and elevated manufacturing costs are discussed, with attention to trade-offs between thermal stability and recyclability. Emerging solutions include hybrid architectures, nanofiller integrations, bio-derived matrices, and self-healing systems, supported by AI-accelerated material discovery. By integrating sustainability with performance, this review provides a comprehensive roadmap for researchers and engineers advancing the next generation of high-temperature polymer composites for automotive applications.