Electrospun supramolecular polymer fibres

The electrospinning of urethane based low molecular weight polymers differing only in the nature of the hydrogen bonding end-groups has been investigated. For the end-groups with the lowest binding constants at maximum solubility only droplets, are produced at the electrode; in contrast, increasing the binding constant of the end-group results in electro- spun fibres being produced. The properties of the fibres produced are subject to changes in solvent, concentration and temperature. Typical diameters for these fibres were found to be some 10 s of lm, rather than the sub-micron dimensions often produced in electrospin- ning systems. Such diameters are related to the high initial concentrations required; this also may influence the rate of solvent removal and preferential surface solidification which feature in these examples. A simple theoretical model is used to relate the association con- stant to the molecular weight required for fibre formation; significantly lower levels of association are required for higher molecular weight macromonomers compared to smal- ler molecular systems.