The Effect of Ethylene Glycol on the Alkali Hydrolysis of Poly(ethylene Terephthalate) Fibers

Ethylene Glycol이 Poly(ethylene Terephthalate) 섬유의 알칼리 가수분해에 미치는 영향

Poly(ethylene terephthalate)(PET) fabrics were treated with various concentrations of NaOH and ethylene glycol(EG) at different temperatures to investigate the effects of EG, which was produced during the hydrolysis of PET by NaOH. The dissolution rate constant was calculated by Kuriyama's equation. It showed a linear relationship to the concentration of NaOH and an exponential relationship to treating temperature the concentration of EG. Apparent activation energy of dissolution was 18.9-21.0 Kcal/mol and decreased slightly with increasing the concentration of EG but no relationship between the concentration of NaOH and apparent activation energy was noted. The tensile strength of NaOH treated filament decreased rapidly with the increase of weight loss and there was no difference between PET filament treated in ethylene glycolic and aqueous NaOH solutions. The density and crystallinity of treated PET increased with the increase of weight loss. It was more prominent in ethylene glycolic than in aqueous NaOH solution. More moisture regain was noted PET fabrics treated in ethylene glycolic NaOH solution in disregard of higher crystallinity, which was assumed to be due to hydrophilic characteristics of sodium carboxylate on the end of PET molecular chains. PET was swelled in EG three times more than in water under the same conditions. The dissolution rate constant in ethylene glycolic NaOH solution was seven to eleven times larger than in aqueous solution and the lower the concentration of NaOH was, the more the effect of EG was.