Double Network Hydrogel from Acrylic Acid

Hydrogels attract great attention due to their soft and wet nature, similar to that of biomaterials. Recent innovations in several tough hydrogels show their potential as structural biomaterials, such as cartilage. In order for tough hydrogels to be used in biomedical applications, their required mechanical properties such stiffness, strength, toughness, damping, fatigue resistance and self-healing, along with biocompatibility are considered for every application. In this study, hydrogels were synthesized batch-wise with acrylic acid, methacrylamide, and poly-propylene glycol diacrylate. Sodium dodecyl sulfate was introduced to the polymer network to reduce the swelling, an issue presented in a water environment. Acrylic acid and methacrylamide are added followed by potassium persulfate in order to randomly co-polymerize the monomers at 75 °C. The resulting material displayed both hydrophilic and hydrophobic interactions, as well as a high tensile strength. The gel formations were physically characterized by Fourier Transform Infrared spectroscopy analysis and UV-Vis spectroscopy. Mechanical properties of the hydrogel were examined using shear rheology and tensile testing.