Ionic Liquid‐Assisted Spinning of Glutaraldehyde‐Modified Melamine‐Formaldehyde Fibers: Process Optimization and Enhanced Mechanical Properties

ABSTRACT Melamine‐formaldehyde (MF) fibers are key flame‐retardant materials for protective textiles and high‐temperature filtration, but their industrialization is limited by high brittleness and reliance on organic solvents. This study proposes a modification strategy using an ionic liquids (ILs)/water system combined with glutaraldehyde (GA) crosslinking. Five ILs exhibiting excellent solubility for MF‐GA (MFG) prepolymers were screened via the COSMO‐RS model. Atomic simulations (Multiwfn and VMD) confirmed that IL‐prepolymer interactions are dominated by hydrogen bond (HBond) and electrostatic forces, with anions playing a significantly stronger role in dissolution and molecular stabilization. Continuous MFG fibers prepared by wet‐dry spinning using the optimized [Emim]DEP/water system showed a 15.8% increase in elongation at break. The char yield reached 22.3% (a 36.8% increase compared to unmodified MF fibers' 16.3%), demonstrating enhanced thermal stability. The performance improvement is attributed to the uniform crosslinked network and the dual function of ILs in plasticizing and stabilizing reaction intermediates through anion‐dominated effects. This integrated “computational screening ‐ atomic simulation ‐ preparation of long fibers” scheme offers a green route for optimizing MF fibers and clarifies the core principle of anion regulation in IL‐prepolymer dissolution.