Viscoelastic of recycled high-density polyethylene (rHDPE) reinforcement with bamboo fiber composite

This study explored the dynamic properties of composites made from recycled high-density polyethylene (rHDPE) reinforced with bamboo fiber. The stiffness and viscoelastic behavior were analyzed using dynamic mechanical analysis (DMA), focusing on storage modulus (E'), loss modulus (E"), and tan delta (δ). The bamboo fiber, sourced from two-year-old Petung bamboo (Dendrocalamus asper), was treated with a 10% NaOH solution to improve compatibility with rHDPE. Results showed that a 30% bamboo fiber composite stored 122.2% more energy than pure rHDPE and exhibited the smallest decrease in storage modulus (78.5%) with rising temperature, indicating excellent thermal stability. The loss modulus for the 30% composite was 43.5% higher compared to lower fiber contents (10% and 20%), which only increased by 7.6% and 29%, respectively. Additionally, the tan δ value rose by 136.6%, reflecting enhanced energy dissipation. These findings demonstrate that bamboo fiber significantly influences the viscoelastic properties of rHDPE composites. Viscoelasticity is crucial for materials exposed to fluctuating loads and temperatures, making these composites suitable for applications like automotive and construction. By combining renewable bamboo fibers with recycled plastics, this research promotes sustainable material development while achieving superior mechanical performance. This innovation not only reduces environmental impact but also offers cost-effective, high-performance solutions. Future work could explore advanced treatments or hybrid composites to further optimize properties for specialized uses.