Molecular Interaction Mechanism and Mechanical Performance of Lignin/Gelatin Composites by Molecular Dynamics Simulation Study

Owing to the weak intermolecular interaction and inferior mechanical properties, the application of biobased gelatin as a textile fiber can be limited. Although lignin is a promising biobased filler for reinforcing gelatin, the interaction mechanism and mechanical performance of lignin/gelatin composites remain insufficiently explored. In this work, the molecular interaction mechanism in lignin/gelatin blends was systematically investigated by using molecular dynamics (MD) simulations. Simulation models of gelatin composites with varying lignin contents (0, 5, 10, and 20%) were constructed to elucidate the influence of the lignin content on the molecular interaction and mechanical performance. The results implied that the addition of lignin into the gelatin matrix has a significant effect on the hydrogen bonding interaction, which is primarily formed between the hydroxyl/amino groups in gelatin and the hydroxyl groups in lignin. The mechanical properties of the 10% lignin/gelatin composite achieved optimal values, attributed to the improved interfacial interaction and compatibility between lignin and gelatin. The simulation findings were further validated by the experimental data. This study provides valuable insights into the potential fabrication of lignin-reinforced gelatin textile fibers with enhanced mechanical properties.