Physiochemical properties of differently pretreated cellulosic fibers

Surface characteristics of differently pretreated flax fibers have been studied using electrokinetic analysis (EKA) and inverse gas chromatography (IGC). Semi-retted and retted flax fibers were scoured and bleached conventionally. All pretreated flax fibers showed negative zeta-potential at all pH values, indicating an acidic fiber surface. The isoelectric point was not reached at pH 3 and can be estimated to be near a pH of 2 or even below, a value where the fibers will be damaged. Inverse gas chromatography measurements showed differences in the surface energy among the differently pretreated flax fibers irrespective of the relative humidity. The group of retted flax fibers in general was found to have higher surface energies than the corresponding semi-retted group. On the other hand, within the same flax fibers group (retted or semi-retted), it was found that the surface energy decreases in the order bleached fibers > scoured fibers > raw fibers.