title: Terahertz time-domain spectroscopy as a tool to monitor the glass transition in polymers.
abstract: We demonstrate the suitability of terahertz time-domain spectroscopy as a non-destructive, contact-free tool to monitor the glass transition in polymers--a core feature of the amorphous phase. Below the glass transition temperature T(g), segmental motions along the polymer chain are frozen due to the lack of free volume between neighboring macromolecules. We show that this transition also reflects in the temperature dependence of the refractive index at terahertz frequencies. Two domains can be identified, which differ in their sensitivity to temperature changes. To verify the proposed approach, we determine the glass transition temperature T(g) of semi-crystalline poly(oxymethylene) (POM) with terahertz time-domain spectroscopy and validate the results by destructive differential scanning calorimetry (DSC) measurements.
authors.affiliation: Institut für Hochfrequenztechnik, Technische Universität Braunschweig, Schleinitzstrasse 22, 38106 Braunschweig, Germany. steffen.wietzke@ihf.tu-bs.de
authors.forename: Steffen
authors.initials: S
authors.lastname: Wietzke
authors.forename: Christian
authors.initials: C
authors.lastname: Jansen
authors.forename: Tilmann
authors.initials: T
authors.lastname: Jung
authors.forename: Marco
authors.initials: M
authors.lastname: Reuter
authors.forename: Benjamin
authors.initials: B
authors.lastname: Baudrit
authors.forename: Martin
authors.initials: M
authors.lastname: Bastian
authors.forename: Sangam
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Martin
authors.initials: M
authors.lastname: Koch