One‐Step Polymethyl Methacrylate Emulsion Synthesis: Feasibility of Lubrication

This study reports the synthesis of polymethyl methacrylate (PMMA) emulsions with varying mass fractions via a one‐step polymerization method and investigates their potential as aqueous lubricants. Comprehensive characterization reveals that PMMA particles exhibit a jellyfish‐like morphology and core‐shell structure, with the 15.04 wt.‐% PMMA‐E‐80 emulsion showing optimal performance. Tribological tests demonstrate that this emulsion significantly reduces friction and wear under water‐lubricated conditions, attributed to the formation of a dense lubricating film on the friction interface through synergistic physical deposition and chemical adsorption of PMMA nanoparticles. This film bears load via elastic deformation, adjusts interfacial shear through macromolecular chain rearrangement, and reduces contact stress by filling surface gaps, while also inhibiting electrochemical corrosion. Beyond lubrication, the emulsion's tunable particle size and film‐forming properties enable potential applications in hydrophobic coatings, adhesion promotion, and functional composite surfaces via additive incorporation. The findings provide a theoretical basis for PMMA emulsions as high‐performance green water‐based lubricants and versatile surface modification materials, highlighting their comprehensive application potential in fields requiring high wear resistance, corrosion protection, and surface functionalization.