A process for the preparation of a crosslinked polymer of a vinyl imidazolium compound

A process for the preparation of a crosslinked polymer of a vinyl imidazolium compound, comprising the steps of - polymerizing a vinyl imidazolium compound in the presence of a crosslinking agent in an aqueous medium, so that a hydrogel is obtained which has a cross-linked polymer of the vinyl imidazolium compound, - drying the hydrogel at an ambient pressure of 0.6 to 1.1 bar to obtain a dried crosslinked polymer obtained from the vinyl imidazolium compound, crosslinked polymer of a vinyl imidazolium compound having improved mechanical properties and use as a medical product