Facile preparation and evaluation of allylamine hydrochloride-based porous hydrogel without calcium and aluminum: an alternative candidate of phosphate binder

In this study, sevelamer analogue porous hydrogels are prepared by a free radical copolymerization method of which allylamine hydrochloride serves as the provider of activated amino groups and N,N′-methylene bisacrylamide acts as the diene monomer. A series of hydrogels are prepared by varying the ratio of allylamine hydrochloride to N,N′-methylene bisacrylamide. The obtained hydrogels are well-characterized by infrared spectroscopy, powder X-ray diffraction and scanning electron microscope. The binding capacities of hydrogels were compared to commercial available preparations. The results demonstrate that prepared hydrogels are capable of removing phosphorus ions from simulated gastroenteric environments. The result indicates that the secondary amines also possess the phosphorus binding capacities. The destructive tests give the result that the prepared hydrogel possesses a good stability in acid environment and oxidation environment, suggesting a good stability in gastrointestinal tract. The obtained hydrogel may have potential applications not only in the treatment of hyperphosphatemia, but also in environmental management and wastewater treatment.