Green and eco-friendly poly(lactic acid) / poly(butylene succinate-co-adipate) foams fabricated via supercritical CO2 foaming for efficient oil-contaminated wastewater treatment.

This work presents a fully bio-based poly(lactic acid) (PLA)/poly(butylene succinate-co-adipate) (PBSA) porous material using supercritical CO2 foaming technology to address oil spill and energy challenges. Incorporating PBSA with varying BA (butylene adipic) segment ratios reduces glass transition temperature of PLA from 67 °C to 55 °C, while cold crystallization temperature of PLA shifts from 122 °C to 103 °C. Additionally, tensile modulus and complex viscosity decrease, owing to flexible chain segments of PBSA. Under optimal PBSA segment ratio (butylene succinate (BS):butylene adipate (BA) = 8:2) and PBSA content (15 wt%), the 15 %-BA20 foam exhibits expansion ratio of 56 and open-cell content of 98.1 %. The improvement in cellular structure significantly enhances the adsorption capacity and hydrophobicity. Oil adsorption behavior with a maximum of 55 g/g for CCl4. After 10 cycles, the 15 %-BA20 foam retains 91 % of its original performance, showing 12 % improvement in reusability compared to PLA foam. 15 %-BA20 foam degrades 6 % in soil over 180 days, 3-fold increase over PLA foam (< 2 %) with similar expansion ratio. PLA/PBSA foams exhibit excellent oil-water separation performance and degradability, making sustainable solution for reducing oil spills.