Abstract
Light resistance and alkali exhaustion of nylon treated with aqueous alkali solution were measured.
(1) Nylon taffeta, when treated in aqueous caustic soda solution, was improved in light resistance. The higher the temperature of the solution, the earlier the improvement was observed.
(2) LiOH, KOH as well as NaOH had good effects on the light resistance of nylon, but Na2CO3 and NaHCO3 had only poor effects.
(3) The treatment reduced the OH- concentration of the solution, that is, alkali was exhausted by nylon. As the OH- concentration of the solution and the time of the treatment increased, alkali exhaustion approached a saturation value, which was approximately equal to the carboxyl group content of nylon.
Alkali is probably exhausted to neutralize the carboxyl group of nylon, but it is still in doubt why neutralization of the carboxyl group can improve the light resistance of nylon.
