Mechanical Properties and Characterization of a Catechol-Polymer Biocomposite for 3D Printable Dental Applications

In recent years, polymers containing catechol groups—originally inspired by the adhesive proteins found in mussels—have drawn growing attention from researchers and biomaterial developers, especially for use in dentistry. These materials exhibit excellent surface adhesion due to the unique properties of catechol groups and their ability to form hydrogen bonds, making them valuable across various applications. Dopamine and its naturally occurring derivative, 3,4-dihydroxyphenylalanine (DOPA), were selected as the foundation for creating a polymerizable monomer. This was achieved through a chemical reaction with methacrylic anhydride to produce dopamine methacrylamide (DMA). The newly synthesized compound was then thoroughly analyzed using FT-IR, 1H-NMR, and 13C-NMR spectroscopy to confirm its structure. Following this, DMA was combined with ethoxylated di-GMA (EBPDMA) in different ratios to develop formulations suitable for DLP 3D printing. To create catechol-functionalized polymers, free radical polymerization was carried out in DMF using dopamine methacrylamide and methyl methacrylate (MMA). The resulting cross-linked polymer networks were analyzed using gel permeation chromatography (GPC), along with FT-IR and 1H-NMR techniques, to better understand their structural characteristics. Finally, the mechanical performance of the developed materials was assessed through a series of tests, including measurements of compressive strength, flexural strength, and hardness, all conducted using a universal testing machine (UTM).