Microbial degradation of thermo-oxidized low-density polyethylene

• Published in: Journal of applied polymer science Vol. 73; no. 8; pp. 1435 - 1440
• Main Authors: Volke-Sepúlveda, T., Favela-Torres, E., Manzur-Guzmán, A., Limón-González, M., Trejo-Quintero, G.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 22.08.1999; Wiley
• Subjects: Applied sciences; Chemical reactions and properties; Degradation; Exact sciences and technology; Fourier transform infrared spectroscopy; Organic polymers; Phanerochaete chrysosporium; Physicochemistry of polymers; polyethylene biodegradation; thermal analysis; Biodegradation; Differential scanning calorimetry; Fourier transformation; Molecular structure; Thermogravimetry; Thermooxidative degradation; Basidiomycetes; Crystallinity; Experimental study; Fungi; Infrared spectrometry; Low density ethylene polymer; Investigation method; Phanerochaete chrysosporium; Structure modification; Pretreatment; Thallophyta
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/(SICI)1097-4628(19990822)73:8<1435::AID-APP12>3.0.CO;2-#

Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) were used to determine the relative heat of fusion, crystallinity, and composition of thermo‐oxidized low‐density polyethylene (LDPE) inoculated with Phanerochaete chrysosporium and incubated for 3 months at 30°C under nonaseptic conditions. DSC analysis of thermo‐oxidized samples (150°C, 120 h) followed by microbiological treatment showed a remarkable reduction on the heat of fusion (36%) compared to that of untreated LDPE. TGA allowed determination of changes due to the biological activity but not those that occurred by thermal treatment. A significant increase in the carbonyl index of the thermally treated (150°C, 120 h) LDPE samples was observed due to the increase in the oxidation level during this treatment. In contrast, the double‐bond index (evaluated by FTIR) increased considerably (23%) as a result of the microbial treatment. The observed structural and morphological modifications of the biologically treated LDPE indicate that the reduction of the chain size may be carried out by scission mechanisms. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1435–1440, 1999