The role of advanced fillers in enhancing thermal, chemical and electromechanical properties of polymer composites: a review

Abstract

Abstract Polymer composites have become indispensable materials for advanced engineering applications due to their lightweight nature, tunable properties, and versatile processing capabilities. The incorporation of fillers particularly ceramic, carbon-based (including graphene and carbon nanotubes), and nanoclay fillers has emerged as an effective strategy to overcome the inherent limitations of polymer matrices and achieve multifunctional performance. This review provides a comprehensive overview of the role of these fillers in polymer composites, emphasizing dispersion behavior, interfacial interactions, and structure-property relationships. The effects of filler type, morphology, size, loading level, and hybridization on mechanical, thermal, thermo-chemical, and electro-mechanical properties are systematically discussed. Special attention is given to nanofiller distribution states agglomerated, intercalated, and exfoliated and their influence on load transfer, crack deflection, barrier performance, and functional enhancement. Processing routes & dispersion-control strategies, including melt blending, solution processing, in situ polymerization, and surface functionalization, are critically examined. The review further highlights synergistic effects of hybrid filler systems and current challenges related to dispersion, scalability, and cost. Future directions in sustainable, hybrid, and bio-based filler designs are also briefly discussed to guide the development of high-performance polymer composites.