Wietzke, S.Reuter, M.Nestle, N.Klimov, E.Zadok, U.Fischer, B.Koch, M.2012-07-032012-07-032011Journal of Infrared, Millimeter and Terahertz Waves, 2011; 32(7):952-9591866-68921866-6906http://hdl.handle.net/2440/71990We have measured the frequency-dependent dielectric function of semicrystalline polybutylene terephthalate (PBT) in the terahertz region between 100 GHz and approximately 2.8 THz. A characteristic band is observed around 2.38 THz. The intensity of this band is a good indicator of the degree of crystallinity of the different samples. A potential assignment of this band is proposed,based on the comparison with spectroscopic data of the structurally very similar polyethylene terephtalate (PET). Furthermore, the frequency-dependent index of refraction of PBT reveals more insight about the morphology and different thermal history of the samples under investigation.en© Springer Science+Business Media, LLC 2011Terahertz time-domain spectroscopypolybutylene terephthalatePBTdegree of crystallinitymorphologystructuremacromoleculeindex of refractionrefractive indexabsorption coefficientthermal historyamorphous domainssemi-crystalline polymernon-destructiveanalysisJournal article002011903610.1007/s10762-011-9810-924546