Synthesis and characteristics of aqueous reactive urethane oligomer containing sulfoisophthalate sodium salt

This research studied urethane oligomers, which contains the sulfonic acid group and different reactive groups. First, the transesterification of dimethyl 5‐sulfoisophthalate sodium salt were performed with ethylene glycol or polyethylene glycol of different molecular weights to produce PEG soft chains possessing sulfonic acid group. Subsequently, isophorone diisocyanate used as a hard chain was connected to the two terminals of the sulfonated diols, which finally were blocked by methyl ethyl ketoxime or hydroxyethyl methacrylate or 2, 3‐Epoxy‐1‐propanol to form three kinds of aqueous reactive urethane oligomers (MSE, HSE, and OSE). The MSE oligomer had the greatest particle diameter, particle variance, and streaming current readings; the HSE oligomer, and the OSE oligomer had the second large and the smallest readings of the aforementioned measurements, respectively; whereas the contact angle and surface tension appeared with an opposite trend. Within the thermal properties of oligomer, the Tg of oligomer followed the trend: OSE < HSE < MSE; however, Tm and ΔH show an opposite tendency. With regard to the reactivity of the oligomers toward PET fabric, the add‐on for the variety of oligomers was in the quantity order of MSE > HSE > OSE series, and the washing durability was rated in the order of HSE > MSE > OSE series.