Polyimide composites represent a class of advanced materials with remarkable mechanical robustness and thermal stability, making them highly suitable for applications in extreme environments. Their unique ability to maintain performance under high temperatures and corrosive conditions, combined with a favorable strength-to-weight ratio, positions them as critical components in aerospace, electronics, and automotive systems. Several leading aerospace and electronics corporations have made significant investments in incorporating polyimide composites into their products, indicating the material’s transformative potential. This review paper provides an overview of mechanical and thermal behaviors of polyimide composites, summarizing recent developments and research trends. It examines the influence of various reinforcements, processing techniques, and composite architectures on material performance under mechanical loading and thermal stress. The paper synthesizes findings from experimental studies and modeling efforts to highlight the critical factors affecting strength, durability, and thermal stability. Discussion and recommendations regarding applications in aerospace, electronics, and other high-temperature environments are provided, emphasizing the challenges and opportunities presented by these advanced materials. This review adopts a broad scope to reflect the interdisciplinary nature of polyimide research. Due to gaps in literature, this work aims to provide a foundational overview that supports future, more specialized investigations.

Design under uncertainty has significantly grown in research developments during the past decade. Additionally, machine learning (ML) and explainable ML (XML) have offered various opportunities to provide reliable predictable models. The current article investigates the use of finite element modeling (FEM), ML and XML predictions, and uncertain-based design of carbon-carbon (C-C) composites for use in ultra-high temperatures. A C-C composite concentrating solar power (CSP) as a microvascular receiver is considered as a case study. These C-C composites are fiber composites with directly integrated carbonized microchannels to form a lightweight, high-absorptivity material that includes an embedded microvascular network of channels. The topology of these microchannels is engineered to optimize heat transfer to a supercritical carbon dioxide (sCO₂) heat transfer fluid. The mechanical characterization of C-C composites is highly challenging. Thus, designing every component made of C-C composites for ultra-high temperature applications needs an uncertainty-based analysis. As a part of a comprehensive project on the development of a novel carbonized microvascular C-C composite, this paper explores C-C composite sensitivity analysis, FEM, ML prediction, and XML analysis. The resulting composite can then be carbonized and coated with an oxidation-resistant coating to form a thermally efficient and mechanically robust C-C composite. An ANSYS 3-D-FE model was used to analyze the CSP’s stress/strain. To consider the variability in the mechanical and thermal properties of C-C composites, various mechanical properties are considered as the ANSYS FEM’s input. A synthetic dataset from 730 ANSYS runs was produced to feed into the ML and XML algorithms for uncertainty analysis and prediction. The ML and XML algorithms could accurately predict the CSP stresses/strains.