Organic Compound Migration in Plastics: Molecular Principles

Mathematical models exist for predicting the migration rate of compounds in polymers so long as diffusion and solubility of the migrating compounds in the polymer are known. Many of these equations have existed and had their validity confirmed by over 100 years of use. However, the application of these models have been limited by the difficulty of quantifying diffusion and solubility values in polymers. This difficulty has resulted in literature data which are highly varied and unreliable. Over the past several years the NCFST has been compiling migration data on organic compounds in plastics.This database appears to be the largest every compiled using a single test method. The data has led to mathematical predictions of migration which have been the basis of millions of dollars worth of decisions concerning plant design and process control for recycled polymers. They have provided a basis for understanding which polymers are recyclable back into food contact polymers and have led to predictions on how likely it is for radiolytic products to migrate from irradiated packages into foods. The data has also provided a basis for determining whether a polymer is a functional (ie effective) barrier in multilaminate structures.