Nylon-PTFE

In the field of polymer engineering, nylon materials are widely used in moving friction parts due to their excellent mechanical strength, toughness, and chemical resistance. However, with the increasing speed of machinery and more complex working conditions, wear under dry or boundary lubrication has become a major issue. To address this, engineers have developed self-lubricating systems that improve nylon’s tribological properties, allowing it to operate stably even with minimal or no lubrication. The key to designing self-lubricating nylon lies in controlling the interfacial energy during friction. Conventional nylon surfaces are prone to adhesive wear because of their strong molecular polarity, which leads to the formation of adsorption layers at the contact interface and increases the friction coefficient. To mitigate this, solid lubricants such as polytetrafluoroethylene (PTFE), molybdenum disulfide (MoS₂), graphite, and aramid fibers are introduced. These fillers form micro-lubrication films on the surface, reducing shear stress and thus minimizing wear. Interfacial compatibility and filler dispersion play a decisive role in composite design. For instance, in PTFE-modified nylon, if the particles are uniformly dispersed and surface-treated with a coupling agent, the friction coefficient can drop by 30%–50%. Moreover, the addition of nano-silica (SiO₂) or carbon nanotubes (CNTs) enhances surface hardness and thermal conductivity, dissipating frictional heat and preventing thermal fatigue or melting adhesion. Importantly, the performance of self-lubricating nylon is not a simple additive effect. Different lubricants can exhibit synergistic or competitive interactions. When PTFE and graphite coexist, they form multi-layer lubrication films — one acting as support, the other providing low-shear sliding — achieving stable tribological balance. Improper ratios or poor adhesion, however, can lead to particle detachment and accelerated wear. Processing quality also affects results. During extrusion or injection molding, improper temperature control may cause lubricant degradation or poor dispersion. Therefore, optimizing melt viscosity and shear rate is crucial. Surface modification methods such as plasma treatment and fiber coating are also used to strengthen interfacial bonding. Future research is moving toward intelligent and sustainable self-lubricating systems, such as incorporating microcapsules that release lubricants when cracks form, enabling self-healing, or combining bio-based nylon with green lubricants. Overall, the design of self-lubricating nylon has evolved from simple material modification to an integrated approach involving physical, chemical, and thermal interfacial engineering.