Enhancing flame retardant and wrinkle-resistant performances of silk fabric with bio-based Maillard reaction products between glucose and poly(glutamic acid)

Bio-based materials have garnered considerable attention in the flame retardant field due to their inherent safety and environmental benefits. This study introduces a novel and eco-friendly flame retardant prepared through the Maillard reaction between glucose and poly(glutamic acid) for treating silk fabric. The study elucidates the synthesis of Maillard reaction products (MRPs) and verifies their deposition onto the silk fabric surface by observing changes in surface morphology, functional groups, and charged characteristics. The flammability tests demonstrate that MRPs treated silk fabric had a high limiting oxygen index of over 27% and a charred length of less than 12 cm, indicating effective flame retardancy. Moreover, the introduction of MRPs led to a significant decrease in smoke release when silk fabric underwent combustion. This observation can be attributed to the enhanced char formation and increased thermal degradation temperature of MRPs treated silk fabric. The electrostatic interaction between silk fiber and MRPs contributed to the fabric's resistance to repeated washing. Moreover, MRPs treated silk fabric retained their tensile properties and showed enhanced wrinkle-resistant performance. Generally, this research opens up a new path for the green preparation of halogen-free and phosphorus-free flame retardant protein fibers.