ELECTROKINETIC PROPERTIES OF MODIFIED POLYESTER FIBERS

Electrokinetic properties of easily dyed cationic dyeable polyester (ED-CDPET) fibers of different deniers and cationic dyeable polyester (CDPET) fibers containing varying numbers of sulfonic groups are examined when cationic dye solutions are streamed through their plugs. There is a decrease in the negative zeta potential with more sulfonic groups in the chemical composition of fibers. This may be attributed to enhanced adsorption of dye cations by the increased number of polar sulfonic groups on the fibers. Of the two fibers, ED-CDPET exhibits lower negative zeta potential compared to CDPET with identical sulfonic group content, which may be attributed to the improved accessibility of the sulfonic groups to the dye cations. Maximum denier ED-CDPET shows the least negative zeta potential of the samples of various deniers studied. Heat setting(at 180 degrees C, 90 seconds) lowers the negative zeta potential, which may be due to decreased surface area. Results in surface charge density and surface conductivity are also discussed.