Effect of hyperbranched surface-migrating additives on the electrospinning behavior of poly(methyl methacrylate)

Poly(methyl methacrylate) (PMMA) was electrospun in the presence of a low molecular weight, hyperbranched poly(ethylene imine) additive partially functionalized with perfluorinated and aliphatic end-groups (M(n) approximately 1600 g/mol). The additive exhibited surface segregation with an insignificant influence on the rheological behavior of PMMA solutions. A morphological transition from beaded electrospun fibers to uniform fibers was observed upon introduction of additive at low PMMA concentrations. XPS revealed a surface enrichment of fluorine and nitrogen, which are both present in the hyperbranched additive. Surface fluorine content depended primarily on the amount of additive in solution, and a dependency on the PMMA/additive weight ratio was not observed.