Effect of Accelerator Structure on the Alkali Deweighting Efficiency of Polyester Fabrics

Surface alkali deweighting is an important link to enhance the added value of polyester (PET) textiles. However, the traditional high-concentration liquid alkali treatment has the problem of high pollution and high risk, which runs counter to cleaner production. To reduce the amount of alkali, quaternary ammonium salt accelerators with different structures were used to improve the alkali deweighting efficiency of polyester fabric. The effects of sodium hydroxide, accelerator dosage, molecular structure of accelerator, and holding time on alkali deweighting of polyester fabric were studied. The mechanism was analyzed based on surface morphology, zeta potential. In addition, the differences, such as hydrophilicity, breaking strength, whiteness, and dyeing properties of pretreated textiles, were further compared. The results showed that the alkali deweighting efficiency of accelerator containing benzyl groups was better than that of the accelerator with same alkyl chain containing methyl groups at the same concentration. Meanwhile, as the hydrophobic chain changes from dodecyl to cetyl, and octadecyl, the deweighting efficiency increased markedly, especially for the accelerator containing benzyl group. The 0.5 g/L of octadecyl dimethyl benzyl ammonium chloride (1827) combined with 10 g/L of sodium hydroxide can save 72.2% of alkali consumption to obtain weight loss rate of 20%. Also, the polyester fabrics treated with accelerators showed good hydrophilicity, breaking strength, and dyeing property compared to conventionally treated polyester fabric with the same weight loss rate. These findings provide a new idea for reducing the amount of alkali effectively and basic dyeing of polyester fabrics.