Article pubs.acs.org/Macromolecules
Mapping the Influence of Solubility and Dielectric Constant on Electrospinning Polycaprolactone Solutions C. J. Luo,*,† E. Stride,†,‡ and M. Edirisinghe† †
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, U.K. Institute of Biomedical Engineering, Department of Engineering Science, Old Road Campus, University of Oxford, Oxford OX3 7DQ, U.K.
‡
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S Supporting Information *
ABSTRACT: Solvent−polymer interactions critically influence not only the viscoelasticity and the critical minimum solution concentration required for electrospinning but also the diameter, crystallinity, tensile strength, aspect ratio, and morphology of the electrospun fibers. Hence, a good understanding of the solvents and nonsolvents available and electrospinnable for a polymer of interest is important. The electrospinnability−solubility map uniquely presents the solubility and the electrospinnability of all solvents for a polymer in a single figure. Poly(ε-caprolactone) (PCL), an important polymer in biomedical applications, has been electrospun in a few conventional solvent systems, but a comprehensive mapping of its solvents for electrospinning has not been performed. Based on 49 common solvents of diverse solubility parameters and functional groups, the spinnability−solubility graph for electrospinning PCL solutions was mapped for the first time to enable a comprehensive understanding of the processability of all solvent choices for electrospinning PCL solutions. Furthermore, to date, many studies have demonstrated the importance of the dielectric constant (relative permittivity) of solvents in solution electrospinning, but few have systematically investigated its influence for a broad range of solvent systems. Based on the comprehensive PCL solvent map, this work studies the influence of dielectric constant of solvent systems on the electrospinning of PCL solutions. PCL (Mn = 80 000 g/mol) fiber diameters
