Effects of electron beam irradiation on commercial polypropylene: Kinetic study of antioxidant degradation

Abstract

The long-term influence of electron beam irradiation on food packaging materials (OPP) was studied. After irradiating the material at dose levels of 2, 5 and 10 kGy, w e have shown a partial or complete disappearance of the antioxidant (Irganox 1010 and lrgafos 168) over time and a release of five new compounds resulting from antioxidant degradation. All of these degradation compounds have been identified and quantitatively analysed in relation to post-irradiation time and absorbed dose. These results allow an explanation of the antioxidants' behaviour during storage of the irradiated polypropylene at room temperature.

Antioxidants and their migration into food simulants on irradiated LLDPE film

“…These degradation products are believed to be formed as a result of reactions between antioxidants and the free radicals formed in the film. During the irradiation, Irgafos 168 yielded 2,4-DTBP by breaking its O-P bond and its corresponding phophate (Bourges et al, 1992). But oxidized form of Irgafos 168 was not detected in this study GC method used.…”

“…They are still under the tests for possible toxicological effects (Lau & Wong, 2000). In order to evaluate the chemical or toxicological risk caused by irradiation, it is necessary to identify and quantify the migration and degradation products (Bourges, Bureau, & Pascat, 1992). As a result of migration, the residues of pentaerythrityl-tetra-kis [3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (Irganox 1010) and octadecyl-3- (3,5-ditert-butyl-4-hydroxyphenyl) used as antioxidants in polyvinyl chloride (PVC), polypropylene (PP) and polyethylene (PE) have been detected in irradiated packaged foods.…”

“…Incremental increases in girradiation proportionally reduced the amounts of extractable degradation compounds depending upon the types of polymer and antioxidant (Sadler et al, 2001). Electron beam irradiation of PP at dose level ranging from 2.5 to 10 kGy yielded radiolysis products, 2,4-di-tert-butylphenol (2,4-DTBP) and tris-(2,4-di-tert-butylphenyl) phosphate from Irgafos 168 and 2,6-di-tert-butyl-p-bezoquinone (2,6-DTBBQ) from Irganox 1010 (Bourges et al, 1992). They were found in aqueous food simulants packaged in PP.…”

“…They were found in aqueous food simulants packaged in PP. Because the absorbed dose by simulants could be lower than the dose absorbed by PP and the migrated compounds from PP were decomposed into unknown products, the quantities of the migrated compounds in simulants were smaller than those of compounds in PP (Bourges et al, 1992;Bourges, Bureau, & Pascat, 1993). A maximum dose needed to deplete Irgafos 168 in highdensity polyethylene (HDPE) was found to be $7 kGy when measured by the infrared (IR) spectroscopy method (Carlsson, Krzymien, Descheˆnes, Mercier, & Vachon, 2001).…”

Evaluation of e-beam, γ- and X-ray treatment on the chemistry and safety of polymers used with pre-packaged irradiated foods: a review

“…There was no eOE ort to quantify yields. Bourges et al (1992Bourges et al ( , 1993 conducted a similar study on Irganox 1010 and Irgafos 168. Following irradiation (410 kGy, e-beam) and storage, Irgafos gave rise only to its corresponding phosphate.…”