Preparation and Adhesive Properties of Complex Gels from Polyaspartamides and Tannic Acid

Several polyaspartamide copolymers were prepared from polysuccinimide, the thermal polycondensation product of aspartic acid, via a successive ring-opening reaction using ethanolamine and other amine nucleophiles. H-1 NMR and FTIR spectroscopy were used to identify the chemical structure of the polyaspartamide copolymers. A complex gel was formed upon adding tannic acid (TA) as both a physical cross-linker and adhesive enhancer to the polymer solution at different compositions in an aqueous system. The complexation behavior was investigated and the adhesive properties of the resulting complex gels were measured and compared each other. The thermal properties of the complex gels were also investigated using thermogravimetric analysis. Strong multiple hydrogen-bonding interactions between TA and the polymer chain are considered to be responsible for the formation of these biocompatible complex gels, which have potential use as novel biocompatible adhesive materials.