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Diffusivity of a drug preservative in bromobutyl rubber
Author(s) -
Hoyt Michelle A.,
Balik C. M.
Publication year - 1996
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.10582
Subject(s) - sorption , desorption , swelling , natural rubber , materials science , thermal diffusivity , polymer , fick's laws of diffusion , penetrant (biochemical) , hildebrand solubility parameter , kinetics , solubility , thermodynamics , polymer chemistry , diffusion , analytical chemistry (journal) , chemistry , composite material , organic chemistry , physics , adsorption , quantum mechanics
Sorption of phenylethyl alcohol (a model drug preservative) by bromobutyl rubber (a polymer used in drug packaging) is characterized by relatively low apparent diffusivities at room temperature (D ≈ 10 −10 cm 2 /s) and a high solubility that leads to considerable swelling of the polymer. The sorption curves for thin samples exhibit non‐Fickian anomalies, which are normally observed only in glassy polymers, including two‐stage sorption and sorption overshoot. The desorption curves were much more Fickian. The swelling kinetics were very slow, and true equilibrium was not reached in the time frame of most of the experiments, which ranged up to 78 days. This produced lower apparent diffusivities and higher activation energies for sorption compared to desorption.