Sustainable lightweight rice husk fiber‐reinforced polypropylene composites: Preparation, properties, and environmental benefits

Abstract Rice husk is a byproduct of rice production, often discarded or burned, leading to environmental pollution. In this study, rice husk fiber‐reinforced polypropylene (RF/PP) composites were prepared using a physical foaming injection molding technique. The effects of fiber content on the physical, mechanical, and environmental properties of the RF/PP composite were analyzed. The results showed that the incorporation of RF reduced the melt flow rate, enhanced the crystallinity of PP, and increased both the density and moisture sensitivity. The RFs were uniformly dispersed within the PP matrix, improving the stability of the foaming process. The developed foamed RF/PP composite not only significantly reduced the material density (by 10%–14%) but also improved mechanical properties, including a 26.18% increase in flexural strength and a 58.85% increase in impact strength, while reducing carbon emissions by nearly 10%. This provides a sustainable solution for applications in automotive lightweighting, construction materials, and related fields. The research results promote the high‐value utilization of agricultural waste, support the development of a circular economy, and provide technological support for companies to fulfill their environmental responsibilities and enhance market competitiveness. Highlights Innovative use of rice husk fibers in sustainable RF/PP composites via foaming. RF improves composite molding and foaming quality. Eco‐friendly solution with reduced density for RF/PP composites. Comprehensive analysis reveals RF's potential in green, lightweight composites.