Non-toxic and Carbon-neutral Green Composites Produced From Polylactic Acid (PLA) With Waste Sunflower Stem

Environmental concerns have significantly influenced the use of biopolymers. Polylactic acid (PLA), a key player in the biopolymer market, is utilised in food packaging, 3D printing, and textiles, and exhibits considerable potential for further development. This study investigates the feasibility of incorporating waste sunflower stalks (WSS) as a reinforcement material into PLA composites to improve material properties and promote sustainability. The composites were prepared with 20% and % 30% WSS concentrations and systematically evaluated for their mechanical, thermal, and morphological properties. The results indicate a significant increase in flexural strength with the addition of WSS, with the 30% WSS composite reaching a value of 96.4385 MPa compared to 93.6538 MPa for pure PLA. Thermogravimetric analysis revealed that WSS-modified composites exhibited an approximately 30–40°C increase in thermal decomposition temperature. Scanning electron microscopy revealed increased porosity in the 30% WSS composite, indicating potential applications as an adsorbent material. Furthermore, water swelling tests demonstrated that the composites maintained their resistance to water absorption. These findings suggest that WSS-reinforced PLA composites exhibit improved thermal properties and increased structural porosity compared to pure PLA, making them potentially suitable for applications such as sound and heat insulation. Additionally, they could serve as environmentally friendly adsorbents for removing pollution from environmental matrices.