Biodegradable poly(lactic acid)-based composite open-cell foam fabricated by supercritical CO₂ foaming for reusable and selective oil-adsorption

Abstract

Addressing the growing challenge of oil pollution, this study presents a green and efficient strategy for fabricating biodegradable poly(lactic acid)/poly(butylene adipate-co-terephthalate)/talc (PLA/PBAT/Talc) composite foams with high volume expansion ratio (VER), excellent compression resilience, and superior oil absorption performance via synergistic melt blending and supercritical CO₂ (scCO₂) batch foaming. By strategically incorporating PBAT (10 wt %) and talc (3 wt %) into the PLA matrix, and by optimizing the foaming temperatures, the melt strength and crystallization behavior were effectively tailored. The resultant PLA/PBAT-T3 foam achieved a VER exceeding 45 and an open-cell content (OCC) of 85%. Cyclic compression tests demonstrated that the PLA/PBAT-T3 foam fabricated at 100 °C exhibited the lowest permanent deformation, indicating superior structural integrity. Remarkably, the foam exhibited equilibrium oil absorption capacities (Q_t) of 22.2 g·g^–1 for silicone oil and 13.4 g·g^–1 for cyclohexane. A significant correlation was established, revealing that Q_t is directly proportional to the multiplication of VER and OCC. The foam also demonstrated excellent reusability, retaining over 85% of its initial absorption capacity after 10 consecutive absorption-desorption cycles. This work provides a viable strategy for engineering biodegradable and recyclable oil-sorbent materials, while also advancing the application potential of PLA-based composites in sustainable environmental remediation technologies.

Graphical abstract

Keywords

poly(lactic acid) / talc / supercritical carbon dioxide foaming / open-cell / cyclic compression / oil absorption.

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