Polymethyl methacrylate (POM) is a linear thermoplastic engineering plastic with a main chain composed of repeating units of (-CH₂-O-). It can be regarded as a “precise sliding component alternative to metals” - it forms a high crystalline structure through the ring-opening polymerization of formaldehyde or trioxymethane under cationic or anionic catalysis, thus possessing extremely high rigidity and hardness, excellent fatigue resistance, low friction coefficient and self-lubrication (outstanding wear resistance), and good resistance to organic solvents and hydrolysis. The working temperature range of POM can reach -40°C to 120°C. POM not only has good dimensional stability but also can be precisely molded through injection molding, extrusion and other processes. It is widely used in precision gears, bearing bushings, conveyor belt chains, lock case bodies, zipper sliders, automotive fuel system components, and medical inhalation devices, etc., in motion transmission scenarios that require high rigidity, fatigue resistance and self-lubrication.