Method of plasticizing and densifying hydrophilic polymeric biomaterials and hydrophilic polymeric biomaterials

A continuous, half-continuous or static method of plasticizing and densifying hydrophilic polymeric biomaterials, said hydrophilic polymeric biomaterial having at least one surface, comprising the steps of:

• (a) providing the hydrophilic polymeric biomaterial;
• (b) softening said surface of the hydrophilic polymeric biomaterial to be compressed by applying heat to increase the temperature of the hydrophilic polymeric biomaterial;
• (c) compressing the hydrophilic polymeric biomaterial by applying an elevated pressure onto the softened surface of said hydrophilic polymeric biomaterial obtained in step (b) at an elevated temperature for a pre-determined period of time;
• (d) decreasing the temperature applied to the hydrophilic polymeric biomaterial;
• and
• (e) decreasing the pressure applied to the hydrophilic polymeric biomaterial;
• wherein:
• a plasticizing liquid is added to said surface of the hydrophilic polymeric biomaterial to be densified before step (b), such that said liquid penetrates said surface during step (b), and
• the plasticizing liquid is a non-imidazolium-based ionic liquid (IL), an organic superbase or a Deep Eutectic Solvent (DES).