Optical and dielectric properties of polyvinylchloride/polymethylmethacrylate blends

The optical and dielectric properties of prepared polyvinychloride/atactic polymethylmethacrylate (PVA/alpha -PMMA) blends are studied as a function o f applied field frequency and PMMA content. The observed optical energy gap s and the energy gap tails were determined from the measured absorption spe ctra. It was found that the applied frequency and the a-PMMA concentration have some effects on the physical parameters such as the optical energy gap , the glass transition temperature (T-g), the dielectric constant, and the refractive index. Correlation between the determined optical energy gaps ar id the measured T-g is presented. The observed changes in these physical pa rameters are due to structural changes in the amorphous domains, impurities and space charge within the interfaces in the mixed phases. (C) 2001 Elsev ier Science Ltd. All rights reserved.