Physicomechanical Properties and Utilization of Hydrogels Prepared by Physical and Physicochemical Crosslinking

Abstract

Research concerning physical hydrogels, their morphological characteristics, swelling ability, and related mechanical properties is of increasing significance over last fifteen years due to their controllable degradability and desirable biocompatibility. Additionally, it is very important that physical crosslinking methods such as freeze-thaw cycling, heat treatment, ionic interactions, hydrophobic interactions, hydrogen bonding interactions, self-assembly stereocomplexation as well as other non-covalent interactions do not require use of chemical crosslinking agents which may induce allergic or toxic side effects. Physical crosslinked hydrogels have found their applications so far in pharmaceutical and medical areas. The engineering applications of physical hydrogels are still limited due to low mechanical toughness and short-term stability. This review explores mainly used physical crosslinking methods with examples of polymers crosslinkable with physical junctions. Special focus is given to methods improving mechanical rigidity of physical hydrogels based on anionic polysaccharides and poly(vinyl alcohol).