Integrated PLA/LLDPE nanocomposites with compatibilizer and hydroxyapatite-zinc oxide: Mechanical, physical, thermal, and morphological properties

• HAp-ZnO HNP was synthesized by mixing HAp and ZnO in ethanol and water, with the pH adjusted to 11 under acidic conditions using ammonium hydroxide. • HAp/ZnO HNP was integrated into the PLA/LLDPE matrix using the LO compatibilizer in an internal mixer under melt-phase conditions at 160°C. • The PLA/LLDPE/LO/HAp-ZnO nanocomposite significantly improved mechanical, physical, and thermal properties. • Enhanced compatibility and uniform nanoparticle dispersion within the PLA/LLDPE/LO matrix were observed after the integration of HAp-ZnO HNP. The integration of Polylactic Acid (PLA)/Linear Low-Density Polyethylene (LLDPE) nanocomposites with Hydroxyapatite-Zinc Oxide hybrid nanoparticles (HAp-ZnO HNPs) as fillers and LLDPE-grafted-Oleic Acid (LLDPE-g-OA) as a compatibilizer was successfully conducted. This study examines the improvement of mechanical, physical, thermal, and morphological properties of PLA/LLDPE blends through the incorporation of HAp-ZnO HNPs and LLDPE-g-OA (LO) to enhance their strength, durability, and biodegradability. The HAp-ZnO HNPs were synthesized by mixing HAp and ZnO in an ethanol-water solution (20:80), adjusting the pH to 11 with ammonium hydroxide, and then applying sonication, filtration, washing, and drying. The nanocomposites were prepared by blending PLA, LLDPE, LO, and 5.0 wt.% HAp-ZnO HNPs in an internal mixer at 160°C. The incorporation of HAp-ZnO HNPs improved tensile strength (9.171 MPa), elongation at break (52.863%), and Young's modulus (487.327 MPa) while reducing water absorption to 0.72%. HAp-ZnO HNPs also accelerated biodegradation, increasing weight loss from 0.73% at 15 days to 15.81% at 90 days. Thermal analysis showed enhanced thermal stability, a higher melting point, and faster degradation due to HAp-ZnO HNPs. FTIR spectra revealed complex interactions among the materials, and morphological analysis confirmed good compatibility with evenly nanoparticle dispersion. These findings indicate the potential of HAp-ZnO HNPs as effective fillers and co-compatibilizers for improving the overall properties of PLA/LLDPE blends.