Characterization of ethylene-vinylalcohol copolymer doped with chlorophyll

Thin films of ethylene-vinylalcohol copolymer (EVAI) doped with different concentrations of chlorophyll, from 5 up to 20 wt%, have been obtained. Studies were carried out utilizing DSC and X-ray diffraction to characterize the thermal and structural properties of EVAI-chlorophyll systems. Results reveal that addition of chlorophyll destroys the semicrystalline structure of the host polymer. The optical properties of pure and doped samples have been discussed by the analysis of the UV absorption spectra in the wavelength range 200-1000 nm. The dependence of the relaxation processes on both chlorophyll concentration and temperature has been discussed using the data from dielectric and isothermal depolarization current measurements. (C) 2002 Elsevier Science Ltd. All rights reserved.