Surface modification and aging effect of polysulfonamide yarns treated by atmospheric pressure plasma

The effect of atmospheric pressure plasma treatment on wettability and dyeability of polysulfonamide (PSA) yarns and aging behavior were investigated. The helium and helium/oxygen plasma-treated PSA yarns were stored for different time varying from 10 to 60 days at the condition of 25 °C and 65 % relative humidity. The water absorption time and K/S value were used to determine the wettability and dyeability of polysulfonamide yarns before and after plasma treatment. The changes in surface morphology and chemical composition were analyzed by Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS). The plasma treatments resulted in the decrease in water absorption time and the increase in K/S value, especially for the helium/oxygen plasma-treated PSA yarns dyed with cationic dyestuff. SEM observation confirmed that the PSA fiber surface was roughed and XPS analysis showed that the polar groups on PSA fiber surface increased after the plasma treatments. As plasma treatment time increased and oxygen gas was added, a greater degree of etching was achieved and more polar groups such as hydroxyl and carboxyl groups produced on PSA fiber surface, contributing to a better wettability and thus a better dyeability of the yarns. Almost no apparent aging effect was observed within 10 days. And then with the increasing storage time, the water absorption time and K/S value firstly quickly and then slowly increased and decreased. However, after 30 days, almost no aging effect was observed. The atmospheric pressure plasma treatment had no obviously influence on tensile strength of PSA yarns.