Modelling migration of substances from polymers into drinking water. Part 2 – Partition coefficient estimations

Publication date: Available online 28 March 2019Source: Polymer TestingAuthor(s): P.V. Mercea, A. Kalisch, M. Ulrich, H. Benz, O.G. Piringer, V. Toşa, R. Schuster, P. SejersenAbstractThe permeation through and diffusion/migration of a series of additives, their degradation products and other organic substances from high density polyethylene, polybutylene, polypropylene and cross linked polyethylene films into water was investigated experimentally with two different methods in the 20–60 °C temperature range. Vapour absorption experiments were also conducted in the same temperature range to determine the equilibrium concentration of some organic substances in the same polymers. The goal was to determine partition coefficients, KPW's, of the investigated substances at a polyolefine-water boundary. It was found that in general the temperature dependence of the obtained KPW's was well represented by the van't Hoff law. Some of these results also suggested that the magnitude of the p KPW's and their apparent activation enthalpies is influenced by the presence of other substances solved in water. The vapour absorption experiments also provided polyolefin-air partition coefficients, KPA's.In the second part of this work the obtained pools of KPW's, for each of the investigated polymers were used to develop an approach to estimate theoretically and without any further experimentation “conservative” partition coefficients, K+PW's, for any organic substance, with a solubility ...
Source: Polymer Testing - Category: Chemistry Source Type: research