(28c) Semi-Crystalline Polymer Dissolution, Recrystallization, and Morphology Response to Solvent Vapor Treatment

Poly(ε-caprolactone) (PCL) is a semicrystalline, biodegradable polyester predominately used in biomedical engineering applications as a tissue scaffold and a drug delivery medium. However, researchers in the packaging industry have expanded its utility by exploiting its biodegradability for sustainable packaging materials. Degree of crystallinity, crystal morphology, and crystallite size are known to affect degradation rates of PCL fibers and films, so morphological control is important to designing PCL materials for its growing applications. Inspired by the use of solvent vapor annealing (SVA) to control block copolymer morphology and solvent-induced crystallization in semicrystalline polymers, we are studying how SVA impacts PCL crystallization processes and crystal morphology for a range of film thicknesses. Using a suite of morphological characterization techniques, including atomic force microscopy, optical microscopy, and X-ray scattering, we investigate the roles of solvent choice, extent of film swelling, and solvent evaporation rate on the final film morphology. Additionally, we utilize in-situ grazing incidence wide-angle X-ray scattering to probe the mechanisms of polymer dissolution during solvent uptake and recrystallization during solvent removal.