Ionizing radiation as adjuvant for the abiotic degradation of plastic bags containing pro-oxidant additives

摘要

The effects of ionizing radiation in promoting the abiotic degradation mechanisms in oxo-degradable plastic bags were studied. Commercial plastic bags, containing pro-oxidant additives, were irradiated with gamma photons and accelerated electrons at doses of 5 and 10 kGy. Then, the irradiated bags were exposed to abiotic degradation, either thermal aging or accelerated weathering. Mechanical and microstructural characterizations were performed to follow the degradation. Plastic bags containing additives did not show important changes in their structure after ionizing radiation and thermal aging. Meanwhile, accelerated weathering combined with gamma photons irradiation produce fragmentation of all the samples after 120 h of degradation. It was concluded that the combination of ionizing radiation and accelerated weathering allows the breakage of polyethylene chains trough accelerating the activation of pro-oxidant additive. Additionally, polyethylene molecules are degraded with pre-treatment of ionizing radiation even if they do not contain the pro-oxidant additive.