SOLVENT SWELLING
Although polyurethane is generally recognised as being highly resistant to solvents, it is nevertheless recommended that where necessary, samples of less common solvents be supplied for evaluation in our laboratory to enable us to supply the most suitable grade. Resistance to solvent swelling is increased as polyurethane hardness increases. All polyurethanes will absorb solvents to some degree. However, what is most important is the ability of the polyurethane to resist edge breakdown when subjected to solvent ingression.