Interaction of a Group of Low Molecular Weight Organic Acids with Insoluble Polyamides I. Sorption and Diffusion of Formic, Acetic, Propionic, and Butyric Acids into Nylon 66

Abstract

Insoluble polyamides are being used more in pharmacy and medicine as containers and parts of devices for the storage and administration of drugs and drug-like compounds. In previous reports, results have been presented which indicate that nylon will attract and sorb solute molecules which have acidic functional groups. The purpose of this study was to investigate the sorption of formic, acetic, propionic, and butyric acids by nylon 66 at a number of temperatures and concentrations. Equilibrium sorption isotherms were prepared from the data to evaluate the degree of sorption. Apparent diffusion coefficients of each of the acids were evaluated by kinetic sorption studies; these values were compared to results obtained by the use of diffusion cells. Results of these experiments revealed that the affinity of the aliphatic acids for the nylon discussed here were less than those having higher molecular weights and/or those weak organic acids having a phenyl group. Insoluble polyamides are being used more in pharmacy and medicine as containers and parts of devices for the storage and administration of drugs and drug-like compounds. In previous reports, results have been presented which indicate that nylon will attract and sorb solute molecules which have acidic functional groups. The purpose of this study was to investigate the sorption of formic, acetic, propionic, and butyric acids by nylon 66 at a number of temperatures and concentrations. Equilibrium sorption isotherms were prepared from the data to evaluate the degree of sorption. Apparent diffusion coefficients of each of the acids were evaluated by kinetic sorption studies; these values were compared to results obtained by the use of diffusion cells. Results of these experiments revealed that the affinity of the aliphatic acids for the nylon discussed here were less than those having higher molecular weights and/or those weak organic acids having a phenyl group.