Photo-Biodegradation of LDPE /banana starch films

Abstract

The effects of starch content, photosensitizer content and compatibilizer on photo-biodegradability of polymer blend films from low-density polyethylene (LDPE) and banana starch were investigated. The compatibilizer and photosensitizer used in the films were polyethylene-graft-maleic anhydride (PE-g-MA) and benzophenone, respectively. Dried banana starch of 0-20% w/w of LDPE, benzophenone of 0-1% w/w of LDPE and PE-g-MA of 10% w/w of banana starch were added to LDPE. The photodegradation of the blend films was performed by an outdoor exposure and simulated condition in Xenotest Beta Lamp. The progress of photodegradation was followed by determining the carbonyl index derived from FT-IR measurement and the change in tensile properties. Biodegradation of the blend films was investigated by microbial degradation and soil burial test. Biodegradation process was followed by measuring the changes in physical appearance, weight loss and tensile properties of the films. The results showed that both photo-and biodegradation rates increased with increasing amount of banana starch, while the tensile properties of films decreased. The blends with higher amount of benzophenone showed higher rate of photodegradation, although their biodegradation rate was reduced with an increase in benzophenone content. The addition of PE-g-MA in polymer blends led to an increase in tensile properties whereas the photo-biodegradation slightly decreased compared to the films without PE-g-MA.