Crystallization of poly(ε-caprolactone) at the air-water interface studied by IRRAS and GI-WAXS. (20th May 2020)

• Record Type: Journal Article
• Authors: Hasan, Nazmul; Fuchs, Christian; Schwieger, Christian; Busse, Karsten; Dolynchuk, Oleksandr; Kressler, Jörg
• Is Part Of: Polymer. Volume 196(2020)
• Publication Date: 2020-05-20
• Subjects: Poly(ε-caprolactone) -- Langmuir film -- Crystallization -- IRRAS -- GI-WAXS; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2020.122468
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Poly (ε-caprolactone) (PCL) dissolved in chloroform was spread on the water surface of a Langmuir trough and after solvent evaporation, the surface pressure vs area ( π-A ) Langmuir isotherm was recorded. An extended plateau region indicates a 1st order phase transition related to PCL crystallization as also confirmed by Brewster angle microscopy (BAM). Infrared reflection absorption spectroscopy (IRRAS) and grazing incidence wide angle X-ray scattering (GI-WAXS) reveal details of the PCL crystallization process on a molecular level. The IRRAS and GI-WAXS experiments confirm that crystallization occurs at the plateau region of the π-A Langmuir isotherm. GI-WAXS also confirms that the polymer chains in the crystals are tilted by ≈ 21° with respect to the water surface normal direction. This value is consistent with IRRAS data at a maximum compression state of ≈ 2 Å 2 . Graphical abstract: Image 1 Highlights: PCL crystallizes on the water surface upon compression. Crystallization can be tracked directly on the water surface with BAM, IRRAS, and GI-WAXS. GI-WAXS confirms an orthorhombic unit cell of PCL. IRRAS and GI-WAXS indicate that PCL chains in the crystalline state are tilted by ≈ 21°.