Generation of multihollow structured poly(methyl methacrylate) fibers by electrospinning under pressurized CO₂

Electrospinning is one of the simple techniques for the production of polymer nano-microfibers. In this study, hollow fibers from poly(methyl methacrylate) (PMMA) were formed by electrospinning under pressurized carbon dioxide (CO₂) in a single processing step. The experiments were conducted at temperatures and pressures in the range 27–37°C and 4–6 MPa, respectively. At 5 MPa, CO₂ seemed to have enough affinity to dissolve a portion of dichloromethane (DCM) to assist its evaporation. Under subcritical CO₂, electrospun products with hollow core fibers having diameters of 4–16 μm were generated. The results confirmed that the change of operating parameters had a strong influence on the morphologies (crack or hollows) of the electrospun products. This study demonstrated that this process offers the possibility that electrospinning under pressurized CO₂ will become an essential and useful method for the generation of polymer structures with hollow interiors. POLYM. ENG. SCI., 56:752–759, 2016.