Biodegradation of lactic acid and polyethylene glycol based polyester urethanes

Abstract

A novel polyester urethane based on lactic acid and polyethylene glycol 400 (PEG400) was synthesized. The biodegradation of the polyester urethane under soil burial condition and by cultured bacteria (Pseudomonas aeruginosa) at different temperatures (5, 15, 37ºC) was studied. The biodegradation was assessed from the weight loss, tensile strength and ultimate elongation as well as chemical changes by FTIR spectroscopy and visual changes by optical and scanning electron microscopy. After 30 days of exposure of the polyester urethane films to cultured Pseudomonas aeruginosa around 33-36% degradation in terms of weight loss was observed. Under soil burial degradation the samples have shown 62% weight loss in 180 days but there is around 98 to 99% loss in tensile strength and elongation at break.