Sustainable fabrication of polypropylene-postconsumer cotton composite materials: circularity, characterization, mechanical testing, and tribology

The processing, microstructure, mechanical properties, characterization, and performance as paradigms play vital in determining a material's ultimate role in commercial applications. Circularity of natural polymer waste is required innovation in industrial processing. In this creative research, an industrial model is introduced for pilot fabrication of polypropylene–postconsumer cotton fiber reinforced composites. International organization for standardization (ISO 9001–2) standards are instigated for selection and categorization of manufacturing techniques and waste. In this research, we applied compression and injection molding techniques to fabricate polypropylene (PP)–cotton composites. Postconsumer cotton waste was used as a reinforcement material. Postconsumer cotton fiber (PCCF) content in the composites was 10, 30, and 40% wt. Injection molding was found to produce composites with better structure than compression molding. As compared to the PP samples, the best results were achieved with 10% wt. Similarly, American standards are established to validate the performance and quality of developed PP-PCCF composites. The PP-PCCF composite (10% wt.) exhibited good mechanical properties with a tensile strength of 26.31 MPa, modulus of elasticity of 1476 MPa, and strain of 8%. The composite of 10% wt. PP-PCCF demonstrated reasonable thermal, wear, and surface properties, including crystallinity of 44%, degradation temperature of 360 °C, wear rate of 3 × 10−6 mm3/Nm in sliding tests against silicon carbide (SiC) sandpaper, the average weight loss of 12 mg/kg in erosion tests, and the surface roughness Ra of 0.20 μm. Theoretical models and experimental investigations (tensile, bending, impact, surface, erosion, abrasion and thermal) are established through quantitative discussion. This pilot framework provides a foundation for the implementation of close loop manufacturing of polymer composites. Moreover, this work also controlled the commercial green production of polymer composites products with negligible waste. The investigated PP-PCCF composite materials have potential applications in the automotive and construction industries.