Circular Economy Solutions: The Role of Thermoplastic Waste in Material Innovation

Plastics play an indispensable role in modern society, yet their long-term durability poses severe environmental challenges, with mismanaged waste polluting ecosystems worldwide. The transition to a circular economy emphasizes the importance of recycling and resource recovery to mitigate these impacts. While conventional disposal methods like mechanical and chemical recycling or incineration face limitations such as quality degradation, high costs, or pollutant emissions, value-added approaches present an innovative solution. This review explores the potential of integrating recycled plastic waste into composite materials to enhance performance and sustainability. Focusing on diverse strategies, the paper highlights the use of recycled plastics in combination with fibers, wood, metal, concrete, glass, rubber, textiles, and foam. These composites demonstrate superior mechanical, thermal, and chemical properties, enabling applications across industries like construction, automotive, aerospace, and furniture. Furthermore, various roles of plastic waste—such as filler, reinforcement, matrix, or additive—are analyzed to showcase advancements in material innovation. By presenting methodologies and outcomes from recent research, this paper underscores the potential of recycled plastics in creating high-performance materials, supporting sustainable development and circular economic goals.