Electrospinning Fabrication, Structural Analysis, Thermomechanical, Lyophobic, and Biocompatible Properties of Cottonseed Protein Isolate/Poly(ethylene oxide) Composite Fiber Mats

Macroscopic, robust, lyophobic, and biocompatible protein fiber mats derived from cottonseed protein isolate (CPI) as a renewable feedstock were successfully fabricated by electrospinning, with the incorporation of poly(ethylene oxide) (PEO) for fiber spinnability improvement. Influences of spinning solution concentration, CPI:PEO ratio, fiber-collecting velocity, and epoxidized linseed oil (ELO) content on the fiber mat properties were investigated. The fiber mats collected at high speeds showed clear increases in tensile strength and stiffness, which were largely due to the stretching effect on favoring polymer chain alignment, crystal orientation, and protein secondary structure ordering, as revealed by SAXS/WAXS and ATR-FTIR peak deconvolution analysis across multiple scales including the fundamental molecular level. In addition, the mechanical properties and thermal stability of the fiber mat can be further improved using ELO as a green cross-linking agent. Furthermore, the CPI/PEO fiber mats show excellent solvent resistance, reduced surface free energy, low water vapor permeability, and superior biocompatibility. The reported fiber mats hold great potential in biomedical dressing, air filtration, and biodegradable packaging applications.