Strength characteristics, structure and wear resistance of ptfe-commercial carbon composites

Abstract

The present work is devoted to investigations of the structure, mechanical properties, and wear resistance of composites based on polytetrafluoroethylene filled by 0.3–20.0% of commercial carbon. The methods used were mechanical testing, X-ray phase analysis, scanning calorimetry, scanning electron microscopy, and triboengineering tests. The wear resistance of low-filled PTFE-based composites containing 1–5% of ultradispersed commercial carbon was found to increase sharply, by up to 500–600 times, whereas the main strength characteristics of these composites, including relative elongation at rupture and tensile strength, remained at levels close to that of pure polytetrafluoroethylene (PTFE). This effect is attributed to the active cross-linking role of ultradispersed carbon particles, which promote the formation of a transient supermolecular structure in the low-filled composites; this structure is a combination of the unfilled PTFE structure and a spherulite-like supermolecular structure.