Long‐term migration data, by radioactivity measurements, are presented for the systems poly(vinyl chloride) (PVC)/labelled dioctyl phthalate (DOP)/methanol, n‐propanol, or n‐butanol. At equilibrium, migration levels determined exceed 85% for methanol and reveal complete removal for the higher alcohols. Migration kinetics failed to be described by the long‐term Fickian approximation with a diffusion coefficient independent of concentration. Nevertheless, qt/q∫, where q∫ the amount migrated at infinite time and qt the amount lost up to time t, increases linearly with (time)1/2/(thickness) during the initial stages of the process and then a linear also relationship appears, but with severely reduced slope. Similar data concerning the systems PVC/DOP/petroleum oils confirm the behavior observed.
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C. D. Papaspyrides (1986) studied this question.
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