Migration Of Chemical Substances In Plastic Packaging Material Under Microwave Conditions

In order to study the migration behavior of chemical substances in packaging material under microwave conditions, this paper researches on migration of polyolefin antioxidants Irganox1076 and Irgafos 168 in reconciled edible oil, maize oil and rapeseed oil under thermal and microwave treatment. Then the results are analyzed by HPLC. The effects of temperature, heating time, microwave power and oil type etc on migration are discussed. At last, comparison between constant-temperature water bath and microwave treatment on migration of antioxidants 1076 and 168 is made. The results of which can provide the base of deeper theoretic research and the guide for subsequent experiment research.Firstly, the diffusion of chemical substances in polymer and its factors are discussed, the single-layer and two-layer model of migration are analyzed too.Secondly, migration behavior of antioxidants 1076 and 168 in 3 edible oils is studied under 20℃, 40℃, 60℃and 80℃and gains following conclusions. Namely, the temperature determines migration kinetics of antioxidants 1076 and 168 such as the higher temperature with the higher migration rate and the shorter migration equilibrium time. Oil type has little effect on migration behavior. Migration rate of antioxidant 1076 is higher than that of antioxidant 168 under the same conditions. In temperature range of 20℃to 60℃, diffusion coefficient (D) of antioxidants 1076 and 168 in PE film has relationship with absolute temperature, namely lg D is linear with the reciprocal of temperature.Then, migration of polyolefin antioxidants 1076 and 168 in 3 edible oils under microwave power of 100W, 250W, 440W, 600W and 900W by a NN-T251W Panasonic microwave oven which is equipped with FISO Microwave Workstation is studied and gains following conclusions. Oil type has little effect on migration behavior and migration rate of antioxidant 1076 is higher than that of antioxidant 168 under the same conditions. The higher microwave power results in the higher migration rate and the higher migration quantity under the same heating time. And the migration quantity of antioxidants is determined by both microwave power and heating time.Finally, the results of migration under microwave treatment is compared with that of constant-temperature water bath treatment, it shows that it is feasible to carry out accelerated migration experiment of chemical substances in packaging material by microwave treatment.