Enhancing the Electrospinnability of Low Molecular Weight Polymers Using Small Effective Cross-Linkers

Abstract

The electrospinning of continuous fibers normally requires the presence of a network of topological entanglements in solution, limiting the spinnability of low molecular weight polymers. Here, we show that a supramolecular approach can improve, and even render possible, the electrospinning of low molecular weight polymers, illustrated here with poly(4-vinylpyridine) (P4VP), by creating effective (i.e., physical) cross-links via hydrogen bonding or coordination interactions in solution using small molecules. The addition to P4VP solutions in dimethylformamide of 4,4′-biphenol (BiOH), which hydrogen bonds to P4VP, and nitromethane, a poor solvent for P4VP that increases BiOH hydrogen bonding to P4VP, decreases the concentration needed to prepare fibers of 50 kg/mol P4VP by a factor of 2 and enables the formation of unbeaded fibers. Hydrogen bonding in solution is quantified by infrared spectroscopy, and the impact of the supramolecular interactions on the P4VP concentration needed to form a physical network...