The Critical Surface Tension of Wool

A rapid method for the measurement of the critical surface tension γc values of individual wool fibers is described. Using this method, a comprehensive study of the wettability of untreated wool fibers has been carried out, and subsequent changes in γc after various chemical treatments have been monitored. It is shown that the value of γc obtained depends on the liquid series used for the measurement; the use of aqueous alkanol solutions for such measurements is criticized. The value of γ c for Hcrcosset-57 has been measured, and the spreading coefficient S and work of adhesion WA for this polymer on wool have been re-evaluated.