Rapid hydrophilic modification of poly(ethylene terephthalate) surface by using deep eutectic solvent and microwave irradiation

Rapid hydrophilic modification of poly(ethylene terephthalate) (PET) fabric was carried out by deep eutectic solvent, ethylene glycol-choline chloride (EGC), under microwave irradiation. EGC is an inexpensive eco-friendly solvent, which is easy to handle along with low toxicity. Results showed that alkali concentration and microwave irradiation time were critical factors in determining surface characteristics of PET. The EGC-treated PET fabric showed highly hydrophobic surface with long wicking time (>2000 s) and high contact angle (135°) at 60 s of microwave irradiation time. However, by merely adding 0.5% sodium hydroxide, the EGC-treated PET fabric surface was drastically changed to highly hydrophilic surface with instant wicking time. The structure of modified PET was studied by various instrumental analyses such as Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy. Tensile strength and methylene blue staining tests were also carried out to determine characteristics of the modified PET fabrics.