Diffusion and solubility of n‐alkanes in polyolefines

The diffusion and partition coefficients (relative solubility constants) of n‐alkanes (from carbon nos. 12–32) have been determined by a permeation method (pouch method) for the polyolefines LDPE, HDPE, and PP–copolymer, and PP–homopolymer at room temperature. The activation energies for the diffusion are interpreted in the meaning of the rate transition theory. Correlations exist between the activation energy δE and the heat of vapourization δvHs as well as between the activation energy δE and the Arrhenius preexponential factors D0. These correlations are useful for the prediction of the diffusion coefficients of n‐alkanes with carbon numbers larger than 32.