Recent Developments in the Mechanical Behavior of Polymer-Based Composites.

Polymer-based systems have been shown to have a particular combination of characteristics that make them desirable in technological sectors, such as lightness, insulating properties, and easy molding during processing, as well as mechanical versatility, which is greatly due to their molecular microstructure. Nevertheless, they still present limitations in mechanical performance and use at moderate/high temperatures, considerably restricting their range of applications. Thus, great efforts have been directed towards developing strategies intended to enhance said characteristics and predict their complex mechanical behavior, with the main goal of adapting their properties to the end-use application. The present review considers the most recent developments, focusing on the research published in 2025 and early 2026, and future challenges in the mechanical behavior of polymer-based materials, being structured according to material considerations, more specifically the development of advanced (nano)composites based on high-performance matrices and functional nanoparticles, as well as bio-based polymer (nano)composites obtained from renewable sources and multifunctional smart and meta-materials for monitoring and long-term use; the development of new processing methods, focusing on advanced additive manufacturing; and the use of artificial intelligence and machine learning. All in all, the final objective is generating knowledge that will enable the preparation of components with tailor-made mechanical characteristics and functional properties, covering material design and processing.