Evaluation of Mechanical Properties and Interface Interactions in Thermoplastic Composites Including Discarded Musical Instrument Reeds

This study investigates the material recycling potential of discarded wind instrument reeds (Arundo donax), which are conventionally incinerated, by compounding them with thermoplastics (thermoplastic polyolefin, TPO; polybutylene succinate, PBS). After recovered reeds were pulverized and injection-molded at 10 and 30 wt% concentrations, their mechanical and interfacial properties were evaluated. Experimentally obtained results indicate that waste reeds function as effective reinforcing agents, particularly when combined with biodegradable PBS. Incorporating 30 wt% reed flour into PBS enhanced flexural strength by approximately 1.7 times and flexural modulus by 2.8 times compared to the neat resin. This superior performance relative to TPO composites is attributed to robust interfacial hydrogen bonding among PBS carbonyl groups and the hydroxyl groups on the reed surface. Additionally, thermal and spectroscopic analyses revealed that these strong interactions elevate the crystallization temperature and generate a “Rigid Amorphous Phase” (RAF) that facilitates efficient stress transfer. These research findings demonstrate the feasibility of creating high-quality, bio-based composites, offering a sustainable method to reduce petroleum reliance and carbon dioxide emissions by upcycling musical waste.