Migration modeling with new polymer-migrant systems

4 Migration modeling with new polymer-migrant systems 

From a practical point of view it is useful to develop a scheme as reliable and as simple as possible to model theoretically the migration in new polymer migrant systems for which experimental data are not yet available. In the following such a step by step scheme will be presented. 

As a first step it is useful to test the interaction between the plastic and food simulants that differ as much as possible from the plastic in their polarities. A quick overview about the absorption behavior of the plastic is obtained by immersion of samples into olive or corn oil at the highest desired used temperature for 1-2 hours and then determining the amount of oil absorbed gravimetrically. 

Once an adequate simulant is selected which shows no or only little interaction with the plastic, the next step is to perform a migration experiment using a well known additive as a reference compound. This selected additive must be well soluble in the chosen food simulant in order to give a guarantee of a partition coefficient as low as possible (Chapter 4). In most cases one can select for this purpose an additive used in the plastic sample under investigation and run the migration experiment as shown in the previous section. 

Once these two experimental steps are done their results can be used to obtain the necessary specific parameters in Eq. (15-3), which then can be used in conjunction with Eq. (7-51) to perform migration estimations for a new or unknown plastic material. 

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