Anisotropic absorption spectra of polyester films in the ultraviolet and vacuum ultraviolet regions

Reflection spectra of polyethylene terephthalate (PET) and polyethylene naphthalate films were measured for 50 to 600 nm, using a Seya-Namioka type monochromator at UVSOR, and were converted into absorption spectra by Kramers-Kronig formula. Dichroic nature of drawn films was clearly displayed in the whole region. Previous analysis was confirmed to be true that the third absorption peak of PET, which appeared in the ' limit of atmospheric measurement, consisted of two peaks of different polarization. Their VI and VII absorption bands at 13.3-15.5 eV originated in transitions associated with sigma electrons, and had absorption coefficients of 1.1-1.3 x 10(6) cm(-1). (C) 2002 Elsevier Science B.V. All rights reserved.