Mechanical and thermal properties of sustainable laminated natural fiber composites reinforced with recycled textile waste

This study explores the sustainable utilization of textile waste, specifically collar strip (Gossypium genus) remnants generated during shirt manufacturing, by incorporating them into polymer composite materials. The waste collar strips were employed as reinforcement in an epoxy resin matrix, combined with natural fibers such as flax, hemp, and bamboo. Among the various composite configurations tested, the flax/textile waste/epoxy (FWF) laminated composite demonstrated superior mechanical performance, achieving the highest tensile strength of 87.53 MPa. Additionally, the FWF composite exhibited the lowest frictional force (6.7 N) and coefficient of friction (0.22), with similar trends observed in flexural strength, impact resistance, and hardness. However, it also showed the highest water absorption rate at 6.78%, attributed to the fine structure and hydrophilic nature of flax fibers. Thermogravimetric analysis revealed that the FWF composite had the highest initial mass (12,500 µg) and a distinct DTG peak near 400 °C, indicating improved thermal stability and strong fiber–matrix adhesion. Furthermore, FWF has a 38% increased thermal conductivity compared to other laminated composites. FTIR spectroscopy confirmed the presence of functional group interactions and chemical bonding within the composite. Moreover, the sound absorption coefficient (SAC) of FWF is 0.24, which is higher than other laminated composites. Surface morphology analysis of the fractured specimens provided insights into the failure mechanisms under tensile loading. Finally, the findings highlight the potential of textile waste from collar strips as a viable reinforcement material for lightweight structural applications.