Tenside-Free Biodegradable Polymer Nanofiber Nonwovens by “Green Electrospinning”

This work highlights the formation and use of tenside-free biodegradable polyester dispersions in water for making water stable nanofibers in accordance with the method of “Green Electrospinning”. The concept was to use the amphiphilic block copolyesters poly[(hexamethylene adipate)-block-(methoxypolyethylene glycol)] (PHA-b-MPEG) and poly[(e-caprolactone)-block-(methoxypolyethylene glycol)] (PCL-b-MPEG) for making tenside-free water dispersions. Different copolymers with varied block lengths were synthesized and converted to high-concentration aqueous dispersions by the solvent displacement method followed by dialysis. The dispersions were electrospun with solid contents of up to 28 wt %. Via addition of small amounts of a high-molecular weight poly(ethylene oxide) as a template polymer, the dispersions were processed to nanofiber nonwovens by electrospinning. Water stable PHA-b-MPEG and PCL-b-MPEG nanofibers were obtained by aqueous extraction of the nanofibers.