Microwave-Crosslinked Polymer Binder MA-AANa/D Biodegradable in an Aqueous Environment–Selected Own Research

The article presents a series of studies on a new polymer binder in the form of an aqueous composition of MA-AANa/D in the aspect of its reusability in the casting process and its safe storage in landfills. FT-IR analysis confirmed that microwave radiation induces crosslinking of both the MA-AANa/D binder and the moulding sand containing it. It was found that after simple treatment of the microwave-cured binder, its original binding properties can be restored, as the hydrogen-bond networks formed under microwave irradiation are reversible. The bending strength (Rgu) tests of both fresh and regenerated moulding sands bonded with MA-AANa/D confirmed that the achieved curing degree meets the requirements for mould and core production. In addition, the biodegradability of the MA-AANa/D binder was evaluated using the Zahn-Wellens test. The progressive biodegradation was monitored through chemical oxygen demand (UV-Vis) measurements and the corresponding biodegradation degree (<i>R_t</i>). The results confirmed that MA-AANa/D is fully biodegradable in aqueous environments, as evidenced by an <i>R_t</i> value of 63.5% after 28 days of testing.