Degradation of polyethylene film samples containing oxo-degradable additives

OXANA YASHCHUK; FLORENCIA PORTILLO; ELIDA HERMIDA

Procedia Materials Science

Elsevier

Año: 2012 vol. 1 p. 439 - 445

2211-8128

The introduction of the so called oxo-biodegradable additives in the Argentine market motivated the assessment of the effects of abiotic and biotic factors on the structure and mechanical behavior of polyethylene with oxo-degradable additives (PE+AD). Samples of oxo-degradable packaging films found in local shops together with polyethylene films with and without d2w® additive (AD) were annealed at different temperatures between 50 and 110ºC and submitted to ultraviolet radiation at different irradiances (0,35; 0,45; 0,89 and 1,20 W/m2). Furthermore, aged oxo-degradable films were set in a controlled compost bioreactor in order to evaluate their biodegradation ability. Experimental results showed that elongation at break was the mechanical property more sensitive to the polymeric degradation. The structural changes determined by FT-IR remarked the importance of the UV degradation time over the irradiation rate; the carbonyl index of the degraded samples pointed out that chain scission was a thermally activated process. Regarding degradation due to UV radiation, at the same dose, the elongation at break is lower at lower irradiance both in PE and PE+AD samples. On the other hand, thermal degradation of PE without additive is more susceptible to degradation than PE + AD. At the beginning of the biodegradation tests, PE + AD showed a higher CO2 production rate with respect to PE; however, this rate reduced along the first 30 days, reaching the CO2 production of PE without additive. The maximum biodegradation observed for both PE and PE+AD samples was 24.0% after 90 days of incubation.