Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Microorganisms
Research on Microbes
Database
Bibliography
Publications
Library
E-Resources
Microbiology Experts
Events
Online Submission
Access Statistics

Site Visitors

blog tracking


 
Polymer Degradation and Stability
Vol.
94, No.6, 2009; Pages: 965 - 970

Abiotic and biotic degradation of oxo-biodegradable polyethylenes

Telmo F.M. Ojeda, Emilene Dalmolin, Maria M.C. Forte, Rodrigo J.S. Jacques, Fátima M. Bento, Flávio A.O. Camargo

Department of Soil, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS 91540-000, Brazil.

Abstract

Conventional polymeric materials accumulate in the environment due to their low biodegradability. However, an increase in the biodegradation rate of these polymers may be obtained with the addition of pro-degrading substances. This study aimed to evaluate abiotic and biotic degradation of polyethylenes (PEs) using plastic bags of high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) formulated with pro-oxidant additives as test materials. These packaging materials were exposed to natural weathering and periodically analyzed with respect to changes in mechanical and structural properties. After a year of exposure, residue samples of the bags were incubated in substrates (compost of urban solid waste, perlite and soil) at 58°C and at 50% humidity. The biodegradation of the materials was estimated by their mineralization to CO2. The molar mass of the pro-oxidant-activated PE decreased and oxygen incorporation into the chains increased significantly during natural weathering. These samples showed a mineralization level of 12.4% after three months of incubation with compost. Higher extents of mineralization were obtained for saturated humidity than for natural humidity. The growth of fungi of the genera Aspergillus and Penicillium was observed on PE films containing pro-oxidant additives exposed to natural weathering for one year or longer. Conventional PE films exposed to natural weathering showed small biodegradation.

Keywords: High-density polyethylene; Linear low-density polyethylene; Pro-oxidant additives; Weathering; Respirometry.


 

 

 
Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution