Comparative Analysis of PET, PTT and PBT Yarns Hydrolyzed by Alkali

Alkaline hydrolysis is a useful method for enhancing properties of polyesters. In this study, the alkali hydrolysis of three polyester filament yarns (poly(ethylene terephthalate) (PET), poly(trimethylene terephthalate) (PTT) and poly(butylene terephthalate) (PBT)) was comparatively investigated under various conditions such as alkali concentration, solvent mixture, process duration and temperature. The weight loss under different conditions was evaluated. Scanning electron microscopy was used for morphological evaluation of the samples. Tenacity loss was also determined for hydrolyzed polyester yarns. While the effect of the different contions on weight loss of PET yarns was the highest, that of PBT yarns was the lowest. While PBT yarns lost nearly their half weight at 100 % ethanol, PTT yarns lost almost all of their weight and PET yarns were completely degraded. PBT yarns showed the fewest diameter loss percentages above 30 ºC. PTT yarns showed the highest tenacity loss for the similar weight loss values.