A Study on Sustainable Eggshell-Derived Hydroxyapatite/CMC Membranes: Enhancing Flexibility and Thermal Stability for Sustainable Development Goals (SDGs)

Carboxymethyl cellulose (CMC) is a biopolymer with promising biomedical applications, and its properties can be enhanced through hydroxyapatite (HA) incorporation. This study synthesized HA from chicken eggshells via the hydrothermal method, aligning with Sustainable Development Goals (SDGs) by valorizing biowaste. The synthesized HA exhibited 35.24 nm crystal size and 86.98% crystallinity. HA was integrated into CMC membranes (i.e. 1 and 5%), with and without polyethylene glycol (PEG-400; as a plasticizer). Increased HA content reduced membrane flexibility, but PEG-400 improved structural cohesion. Microscopic analysis revealed better HA dispersion at 5% loading, enhancing membrane performance. Thermal gravimetric analysis confirmed improved thermal resistance, evidenced by a higher decomposition onset temperature. These findings suggest that CMC/HA composite membranes, especially with PEG-400, offer sustainable solutions for biomedical applications, demonstrating superior mechanical and thermal properties while promoting eco-friendly material utilization from biowaste.