Supramolecular adhesive gels based on biocompatible poly(2-ethyl-2-oxazoline) and tannic acid via hydrogen bonding complexation

A facile fabrication of strongly adhesive hydrogel based on high-molecular-weight poly(2-ethyl-2-oxazoline) (PEOX) and tannic acid (TA) has been demonstrated. PEOX and TA form instantaneous complex gel via strong hydrogen bonding interaction by simple mixing in an aqueous system. The characteristics of the PEOX-TA complex gels was investigated by using Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and scanning electron microscopy to reveal their network structure, composition, and thermal properties. The prepared wet complex gel system demonstrated excellent adhesive performance on different substrates with comparable results to pure PEOX polymer. It was considered that many factors affect the adhesive performance of the PEOX-TA gel such as the TA content, the molecular weight of PEOX, and water content. This adhesive gel system has potential for use in various fields including biomedical application as a novel and low-cost adhesive or sealant. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48285.