Poly(ester amide urethane) Nanocomposites with Biochar and Bentonite Clay for Environmental Remediation

ABSTRACT This study explores the synthesis of biochar from kraft lignin, followed by its modification with epichlorohydrin and triethylamine, and its integration into a poly(ester amide urethane) matrix along with bentonite nanoclay particles to produce a polymer nanocomposite via a feasible approach. The comprehensive resulting nanocomposite exhibited remarkable mechanical features, displaying a toughness of 87.45 MJ/m 3 and a 160% increase in tensile strength compared to the pristine poly(ester amide urethane) matrix. Furthermore, substantial improvement in thermal properties was observed, with T g of the nanocomposite reaching 84.56°C, indicating enhanced thermal stability. Notably, the nanocomposite also exhibited inherent biodegradability, reinforcing its environmental sustainability. Beyond its mechanical and thermal performance, the nanocomposite demonstrated significant efficacy as an adsorbent, effectively removing heavy metal ions, viz., Pb(II), Zn(II), and Cu(II) from aqueous solutions, with removal efficiencies of 80.38%, 76.06%, and 70.80%, respectively. Kinetic analyses indicated that the adsorption process closely adhered to the pseudo‐second order (PSO) model, while the Langmuir adsorption isotherm provided insights into the sorptive behavior. The nanocomposite also exhibited excellent regeneration potential over five cycles, underscoring its economic feasibility and long‐term sustainability as an adsorbent. This study highlights the considerable promise of biochar‐based polymer nanocomposites in advancing material properties and environmental remediation applications.