A Review on Formulation of Polyester Resin From Recycled PET and Its Composite With the Incorporation of Metallic Fillers: Utilization of Recycled PET Products

ABSTRACT The review paper explores the innovative utilization of recycled polyethylene terephthalate (PET) waste in synthesizing advanced polyester resin‐based composites, particularly through integrating metallic nanofillers. PET, a highly durable and versatile polymer, poses significant environmental challenges due to its non‐biodegradable nature and extensive use, especially in consumer packaging. The paper examines chemical recycling methods such as glycolysis, methanolysis, hydrolysis, and aminolysis, which depolymerize PET into monomers that can be repolymerized into unsaturated polyester resins (UPRs). These UPRs, reinforced with metallic fillers like iron oxide, alumina, nickel, and copper, exhibit enhanced mechanical, thermal, and magnetic properties. The incorporation of these nanofillers significantly improves composite matrices, increasing tensile strength, thermal stability, conductivity, and magnetic responsiveness, thus making them suitable for applications in electronics, automotive, and structural industries. This study highlights the synergistic effects of multi‐filler systems, which provide superior reinforcement by altering thermal conductivity and electromagnetic absorption properties. Furthermore, this review promotes the circular economy, demonstrating how PET waste can be transformed into high‐performance, sustainable composites, thereby reducing environmental impact and conserving resources. Future research is directed toward optimizing nanoparticle dispersion and developing multi‐functional composites tailored for specific high‐performance applications. This paper contributes valuable insights into sustainable materials science by advancing Recycling Technologies and Hybrid Nanocomposites Development.