Solubility considerations in relative block crystallization and morphology of PEO‐b‐PCL films. Issue 3 (17th February 2020) - Tower, Cole W.
Abstract: Poly(ethylene oxide)‐ block ‐poly(ε‐caprolactone) (PEO‐ b ‐PCL) is a heavily investigated amphiphilic crystalline‐crystalline diblock copolymer. Its macroscopic physical properties are influenced by the crystallization behavior, which is robust due to similar crystallization temperatures of PEO and PCL. As such, tailoring the crystallinity and crystalline morphology should be advantageous to achieving desired changes in film properties. One method to manipulate the crystallization, analyzed here, is the selective solvation of one block during solvent casting. By careful solvent selection, the crystallization of PEO and PCL during solvent evaporation led to changes in relative crystallinity and film morphology. The effect of environmental humidity on the crystallization mechanism and relative block crystallization was explored in detail using Fourier‐transform infrared spectroscopy. Abstract : Crystallization in polymers is a physical property that has a strong influence on other engineering properties, such as strength and degradation rate. This research shows that crystallization in copolymer films with two types of crystals is manipulated by film fabrication conditions, namely casting solvent and drying temperature. Control over the crystallization process allows for control over macroscopic properties.