Waterborne polyurethane molecular structure designed and its acetic acid and ammonia absorption efficiency

In this study, waterborne polyurethane (WPU) resins consisted of carboxylic acid and side-chained EO (ethylene oxide) functional groups were prepared via a prepolymer ion-hybrid reaction process. After dipping the WPU on fabrics, the dipped fabrics showed promising deodorization properties for both basic and acidic odors and also showed good wash durability because of the presence of those characteristic groups. Basic odors were neutralized via carboxylic acid groups on the WPU, whereas acidic odors were absorbed by the EO groups through hydrogen bonding. Fourier transform infrared spectroscopy (FT-IR) was used to examine the functional groups of carboxylic acid and EO groups, before and after dipping the WPU on the fabrics. The deodorization properties of the dipped fabrics were associated with the content of the functional groups existing on the WPU molecular chain. Scanning electron microscope (SEM) analysis also revealed that the dipped fabrics had a promising wash durability and deodorization properties after 5 times of laundering because WPU particles were still strongly adhered to the fabrics. More side-chain EO groups, more acetic acid molecules were absorbed; while more-COOH groups in polymer chain, more ammonium molecules were absorbed. Table 2 shows that the synthesized WPU’s possess very highly washed durability.