Abstract
The permanganic etching method was applied to various poly(ethylene terephthalate) (PET) fibers having different crystallinity. It turned out for each filament of the PET fibers that the reduction of fiber diameter and the treatment time of etching have a rectilinear relationship between them, as in the case of aqueous alkaline hydrolysis of PET ones. We could express well this rectilinear relationship with a mathematical equation derived from a simple model for etching. A correlation between the apparent rate constant and the amorphous content for as-spun fibers suggested the fact that amorphous portions of PET fiber were preferentially removed by permanganic etching. This fact was confirmed from the evaluation of relative crystallinity of the etched surface region by the microlaser Raman measurement for a given fiber.
