From nature to application: Transformative developments in natural rubber compounding

Natural rubber (NR) is a high-performance elastomer valued for its elasticity, tensile strength, and tear resistance, making it indispensable in diverse industrial applications, including automotive tires, vibration-damping systems, medical devices, and consumer goods. However, conventional synthetic additives used in NR compounding pose environmental and health concerns due to their persistence, toxicity, and non-renewable origin. This review critically examines recent developments in natural-based additives—sourced from plants ( e.g., lignin and vegetable oils), animals ( e.g., collagen and chitosan), and minerals ( e.g., silica and clay)—and their integration into NR compounding and processing. The discussion highlights how these bio-derived alternatives influence rheological, mechanical, thermal, and chemical properties of NR compounds, with comparative insights against conventional formulations. Challenges related to additive availability, processing behavior, cost, and suitability for high-performance applications are highlighted, alongside their potential to reduce reliance on petroleum-based materials. Finally, emerging directions such as smart/nano-enabled additives and AI/ML-driven formulation optimization are considered, underscoring the potential for natural-based additives to advance environmentally sustainable practices while meeting evolving industrial demands. • Natural additives are explored for their effectiveness in NR compounding. • Natural additive-based NR products adhere to green chemistry concepts. • Minerals similarly affect NR compounding as do other natural materials. • NR properties are tailored with natural additives for innovative applications. • Shifting to sustainable NR products enhances eco-practices in the rubber sector.