Prediction of Diffusion Coefficients in Plastic Materials

Plastics properties can be tailored through control of their syntheses and processing to fit every desired application, packaging beeing a major one. Measurable residual amounts or conversion products from the many different raw materials and processing aids used in the various plastic synthesis processes can remain in the finished material along with many chemically different additives which are incorporated into the polymer matrix. All these compounds can diffuse from the plastics into its environment, for example into foodstuffs, pharmaceuticals or other goods packed in plastic materials, as well into the atmosphere and other environments. A theoretical modeling of diffusion coefficients of n-alkanes in a polymer, wich allows to better correlate the diffusion behavior with well defined properties of the polymer matrix, is presented.