Preparation of the Pure Poly(ϵ-caprolactone)-Urea Complex by Electrospray

Abstract

In this work, we demonstrate that electrospray is a simple and efficient method for preparing pure supramolecular complexes between a polymer and a small molecule. Such complexes are often difficult to prepare by conventional methods because of the kinetically favored crystallization of the small molecules. However, the fast solvent evaporation involved in electrospray can circumvent small molecule crystallization. Pure samples of the poly(ϵ-caprolactone)-urea complex were successfully prepared for the first time using the electrospray technique. Infrared spectroscopy, X-ray diffraction and differential scanning calorimetry were used to confirm the purity of the electrosprayed complex and to determine the phase diagram for this system. The electrospray method is similar in concept to the electrospinning approach that we have recently demonstrated, but it proves to be complementary for some challenging samples such as the poly(ϵ-caprolactone)-urea complex.

Keywords:

• Electrospray
• Phase diagram
• Poly(ϵ-caprolactone)
• Supramolecular complex
• Urea

ACKNOWLEDGMENTS

This work was supported by a grant and a graduate scholarship (HA) from the Natural Sciences and Engineering Research Council of Canada (NSERC). We thank Dr. T. Maris and S. Essiembre for their help with the XRD and DSC measurements.