Superhydrophobic PBAT/PLA Fibrous Membrane with Excellent Mechanical Performance for Highly Efficient Oil–Water Separation

Polylactic acid (PLA) membranes offer advantages such as biodegradability, non-toxicity, and biocompatibility for oil–water separation. However, it remains challenging to fabricate PLA membranes with sufficient mechanical strength and hydrophobicity for practical applications. In this study, a superhydrophobic fibrous membrane based on PLA and Polybutylene terephthalate adipate (PBAT) is prepared via electrospinning, followed by a high-humidity treatment. The effects of PBAT content and high humidity treatment on the morphology, hydrophobicity, and mechanical properties of PBAT/PLA composite fiber membranes are investigated. The results show that the introduction of PBAT effectively enhances the fiber diameter, crystallization, hydrophobicity, and mechanical properties of PBAT/PLA fibers. Moreover, the high humidity treatment further improves the mechanical and hydrophobic properties of the membranes. When 0.2 g of PBAT is added and the high humidity treatment lasts for 24 h, the resulting PBAT/PLA fibrous membrane exhibits an outstanding water contact angle (WCA) of 158.23°, tensile strength of 3.802 MPa, excellent oil–water separation flux (6500 L/(m²·h)), and efficiency of 99.80%, demonstrating great potential for oil–water separation applications.