Electrospinning of alkyne polycarbodiimide fibers

A small series of alkyne polycarbodiimides was thoroughly examined using electrospinning technique. To generate various elongated morphologies including fibers with a diameter ranging from 446 nm to 3.3 µm, we utilized solvents such as pyridine, dichloroethane, and tetrachloroethane. The choice of solvent was dictated by particular polycarbodiimide backbone structure bearing alkyne terminated alkyl pendants. In addition to our findings of continuous fibers by the scanning electron microscopy (SEM), we also applied optical microscopy to discover secondary structures, such as hemispheres and beads which may result from concentration/ solubility issues. The major finding is that heavily grafted alkyl polycarbodiimides are more prone to form discrete fibers, i.e., the presence of n-hexyl and n-dodecyl side chains may facilitate electrospinning. Overall, rigid polymer scaffolds carrying modifiable flexible pendants with functional groups seemed to be highly important and practical for various material science applications, such as development of carbonized fibers and novel drug delivery platforms.