Polymer PU–PTHF–PU Significantly Enhances the Mechanical Properties of Poly(lactic acid) Matrix Oil–Water Separation Fiber Membranes

As the global economy continues to expand, the issue of oily wastewater pollution has garnered significant attention. Consequently, this paper reports a poly(lactic acid)-based coblended fiber membrane for oil–water separation. The synthesis of a polyurethane–poly(tetrahydrofuran)–polyurethane (PU–PTHF–PU) polymer at 25 °C and its incorporation at 20 wt % into fibrous membranes resulted in a water contact angle of 138°. The coblended fibrous membranes exhibited a tensile strength of 8.05 MPa and an elongation at break of 46.53%, simultaneously improving the rigidity and toughness of the fiber membrane, endowing the poly(l-lactic acid) (PLLA) fibrous membranes with good hydrophobicity and mechanical properties. Featuring a maximum permeate flux of 3898 L·m–2·h–1, an oil recovery efficiency of 99.4%, and outstanding stability and durability, the PU–PTHF–PU/PCL/PLLA [PCL = poly(ε-caprolactone)] fibrous membrane represents an ideal solution as an all-biobased biodegradable membrane for oil–water separation.