Aggregation behavior and hydrolysis rate of amphiphilic water-dispersed polyester with different contents of sulfonate groups in NaOH aqueous solution

Abstract

Amphiphilic water-dispersed polyester (WPET) has broad application prospects in the textile field. However, due to the potential interactions between WPET molecules, the stability of WPET solution is susceptible to external factors. In NaOH solution, WPET was first aggregated and then hydrolyzed, and the molecular structure of WPET had a certain effect on the aggregation behavior and hydrolysis rate. In this paper, the aggregation patterns and hydrolysis rate of hydrophilic WPETs with different sulfonate contents in NaOH solution were studied. The results showed that the sulfonate content had a great effect on the aggregation behavior and hydrolytic process in NaOH solution in the PEG-free water-dispersed polyester. Compared with the water-dispersed polyester 9.5 % S-0 % PEG with low sulfonate content, the conformation of the water-dispersed polyester with high sulfonate content 14.1 % S-0 % PEG was looser (ρ = 1.65), and NaOH was more likely to penetrate into the molecule. Hence it is more sensitive to NaOH solution and has the characteristics of rapid aggregation and rapid hydrolysis. The increase of NaOH concentration can accelerate the aggregation and hydrolysis of WPET. Furthermore, the aggregation mechanism of WPET in NaOH solution was revealed. These findings are very useful for predicting the stability and phase transition of water-dispersed polyester in NaOH solution and are of great significance for promoting the application of water-dispersed polyester in the textile field.