Evaluation by IR spectroscopy of the degradation of different types of commercial polyethylene exposed to UV radiation and domestic compost in ambient conditions

• Published in: Journal of applied polymer science 2021-04, Vol.138 (14), p.n/a
• Main Authors: Martínez, Karla I., González‐Mota, Rosario, Soto‐Bernal, Juan José, Rosales‐Candelas, Iliana
• Format: Article
• Language: English
• Subjects: Biodegradability; Biodegradation; Carbonyls; Composting; domestic compost; Exposure; fotodegradation; High density polyethylenes; Infrared spectroscopy; IR spectroscopy; Low density polyethylenes; Materials science; Oxidation; Polyethylene; Polyethylene films; Polymers; Polysaccharides; Spectrum analysis; Ultraviolet radiation; UV‐B radiation
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.50158

Different types of commercial polyethylene films, low‐density polyethylene (LDPE), high‐density polyethylene (HDPE), and biodegradable polyethylene (BIO‐PE), were exposed to UV‐B radiation at different exposure time and domestic composting during spring and fall at ambient conditions. The effects of UV‐B radiation and domestic composting on LDPE, HDPE, and BIO‐PE degradation were characterized by FTIR spectroscopy. LDPE, HDPE, and BIO‐PE exposed to UV‐B radiation underwent photo oxidation reactions leading to the formation of carbonyl (CO) and vinyl (CH2CH) groups and hydrophilic surface modification. Also, the exposure of LDPE, HDPE, and BIO‐PE to domestic composting at ambient conditions at different seasons suffered biodegradation reactions leading to the formation of polysaccharides. In both different seasons LDPE, HDPE, and BIO‐PE underwent partial biodegradation, remaining in the domestic composting as unwanted polymer debris. However, biodegradation in domestic composting is not recommended as feasible disposal routes for nonbiodegradable and commercially labeled as biodegradable PE. Commercial polyethylene films of different types were exposed to UV‐B radiation in order to increase their biodegradation in domestic compost. UV‐B radiation causes PE chain scission and photooxidation reaction, leading the modification of the chemical structure. UV‐B radiation causes the formation of unsaturated chemical groups, increasing the biodegradability of all the types of PE analyzed; nevertheless, during domestic compost treatment they underwent only partial biodegradation, remaining in the compost as polymer debris.