Thermo-Oxidation and Biodegradation Study of Low-Density Polyethylene /Starch Films by IR Spectroscopy

This article reports a study of the thermo-oxidation and biodegradation in the soil of low-density polyethylene/starch films (LDPE/starch) by infrared spectroscopy: Films of LDPE/Starch blends of different composition (starch content range from ۰ to ۱۵% w/w),were prepared and exposed to thermo-oxidation at different temperatures at ۸۰, ۹۰ and ۱۰۰°C,and buried in the soil of public dump during ۳۰۰ days. The oxidation, for films subjected to thermal oxidation, was revealed by the appearance of absorption bands of carbonyl groups centered at ۱۷۱۵ cm-۱. After the induction period, which varies from ۱۲ to ۱۴ days according to the concentration of starch incorporated in the films, the indication of carbonyl croup increases with time and temperature of exposition. During the first ۳۰ days, the rate of oxidization is the weaker, the larger percentage of starch in the film of LDPE. The biodegradation of films buried in the soil for ۳۰۰ days, was followed by infrared spectroscopy. The carbonyl index calculated at ۱۷۱۵ cm-۱ and at ۱۷۴۴ cm-۱ showed the oxidation of films LDPE/starch. This index increases with time of burial and starch percentage incorporated into LDPE films during the first ۱۸۰ days in soil burial, then decreases.

کلیدواژه ها:

Low-density Polyethylene (LDPE) ، Starch ، Biodegradation ، Thermo-oxidation ، Blends