Tailoring the Morphological, Thermal, and Rheological Behavior of Melt‐Compounded PHBV Bionanocomposites with Natural Attapulgite Nanoclay

ABSTRACT The aim of this study was to incorporate attapulgite (ATP) (a naturally abundant nanoclay found in Algeria) into biodegradable poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) in order to enhance the thermal, crystallization, and viscoelastic properties of the resulting bionanocomposites. PHBV/ATP bionanocomposites containing 3 and 5 wt.% ATP was fabricated via melt compounding. Comprehensive physicochemical characterization of purified ATP confirmed its nano‐fibrous morphology and excellent thermal stability, as evidenced by SEM and TGA analyses. At 3 wt.% loading, ATP was homogeneously dispersed within the PHBV matrix, leading to significant improvements in thermal stability (increased onset decomposition temperature), enhanced crystallization behavior (higher crystallinity degree), and improved complex viscosity and storage modulus, indicating a reinforcement effect on the polymer's viscoelastic response. These enhancements are attributed to effective polymer‐clay interfacial interactions and the high aspect ratio of ATP nanorods. However, at 5 wt.% ATP, SEM revealed partial aggregation of the nanoclay, which disrupted the polymer matrix continuity and resulted in marginally reduced performance compared to the 3 wt.% formulation. This work highlights the potential of valorizing locally sourced Algerian ATP as a sustainable nanofiller for producing high‐performance, eco‐friendly PHBV‐based bionanocomposites for applications such as packaging and agricultural materials.