Abstract
Blends of two biodegradable polymer, polyvinyl alcohol (PVA) and 2-hydroxy ethyl cellulose (2HEC) were prepared with different compositions by using cast technique. X-ray diffraction (XRD) scans revealed the semi-crystalline nature of the blends for low concentration of 2HEC up to 50 wt% and the amorphous nature for higher ones. Infrared spectra (IR) of blend samples indicate that there is a compatibility between PVA and 2HEC through the formation of hydrogen-bonding between their polar groups. The absorption coefficient spectral analysis revealed the existence of long and wide band tails of the localized states. The absorption edge and band tails were estimated for pure and blend films from their optical absorption spectra. The thermal stability and thermal behavior of blends were investigated under non-isothermal conditions by thermogravimetry (TG) and differential thermal analyses (DTA). A single glass transition temperature for each blend was observed, which supports the existence of compatibility of such system. The kinetic parameters such as activation energy, entropy, enthalpy and Gibbs energy based on TG data for all samples in first decomposition region were determined using Coats-Redfern relation.