Temperature-dependent IR-transition moment orientational analysis applied to thin supported films of poly-ε-caprolactone. Issue 48 (30th November 2017)

• Record Type: Journal Article
• Authors: Kossack, Wilhelm; Schulz, Martha; Thurn-Albrecht, Thomas; Reinmuth, Jörg; Skokow, Viktor; Kremer, Friedrich
• Is Part Of: Soft matter. Volume 13:Issue 48(2017)
• Page Start: 9211
• Page End: 9219
• Publication Date: 2017-11-30
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/c7sm01988b
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : A novel experimental setup based on infrared spectroscopy is described. It enables one to determine the molecular order of amorphous strands and crystalline lamellae in polymer films depending on temperature. Abstract : A novel experimental setup is described which enables one to carry out infrared transition moment orientational analysis (IR-TMOA) depending on temperature. By this, three dimensional molecular order parameter tensors of IR-active transition dipole moments with respect to the sample coordinate system can be determined in their thermal evolution (35 °C < T < 59 °C). As an example crystallinity and macroscopic order of poly-ε-caprolcatone are monitored. Both remain largely unaltered up to T ∼ 50 °C, above which they decrease. These reductions are explained as the melting of flat-on crystalline lamellae that make up about 34% of the crystalline material. The remaining crystallites are arranged into bulk-like, confined spherulitic structures and do not melt by more than (3 ± 3)%. Therefore, flat-on oriented lamellae are supposed to be kinetically favored by confinement during melt crystallization but are thermodynamically less stable than two-dimensionally confined bulk-like spherulites.