Efficient Production and Experimental Analysis of Bio-Based PLA-CA Composite Membranes via Electrospinning for Enhanced Mechanical Performance and Thermal Stability

Environmentally friendly biopolymer nanofibrous composite membranes with enhanced mechanical properties and thermal stability were fabricated via electrospinning with different compositions of polylactic acid (PLA) and cellulose acetate (CA). Firstly, PLA and CA composite membranes were prepared and optimized. Then, the optimized membranes were annealed at temperatures ranging from 80 °C to 140 °C, for annealing times between 30 and 90 min. The developed membranes were characterized by FE-SEM, XRD, FR-IT, TGA, DSC, tensile testing, water contact angle, and resistance to hydrostatic pressure. PLA 95-CA 5 was the optimum composite, with a tensile strength 9.3 MPa, an average fiber diameter of 432 nm, a water contact angle of 135.7°, and resistance to a hydrostatic pressure of 16.5 KPa. Annealing resulted in further improvements in different properties. The annealed membranes had thermally stable microporous structures, without shrinkage or deterioration in nanofiber structure, even at an annealing time of 90 min and an annealing temperature of 140 °C. By increasing either the annealing time or temperature, the crystallinity and rigidity of the nanofiber composite membranes were increased. The annealed membrane demonstrated a tensile strength of 12.3 MPa, a water contact angle of 139.2°, and resistance to a hydrostatic pressure of 36 KPa. Electrospinning of PLA-CA composite membranes with enhanced mechanical properties and thermal stability will pave the way for employing PLA-based membranes in various applications.