Self-reinforced polymer composites based on polytetrafluoroethylene

The development of self-reinforced polymer composites, representing a relatively new group of composite materials, is a promising direction in the field of polymer chemistry. The method of self-reinforcement is used to combine the materials of a single polymer possessing different molecular, supramolecular, and structural features. The high adhesion and mechanical properties of such self-reinforced composites are achieved by the formation of a homogeneous system without an interfacial boundary. In addition, self-reinforcement offers the opportunity of using polymer waste for manufacturing high-strength composites, thus contributing to environmental load mitigation. In this work, we investigate the phase composition and properties of self-reinforced polymer composites based on polytetrafluoroethylene. Self-reinforced composites were prepared by mixing powders of industrial and recycled polytetrafluoroethylene followed by compression molding and pressureless sintering. The crystallinity degree of the as-obtained materials calculated by X-ray phase analysis equaled 41–68%. The performed dynamic mechanical analysis showed that the introduction of a powder of regenerated polytetrafluoroethylene into industrial polytetrafluoroethylene increases the elastic modulus of the obtained materials significantly (up to 2.0–3.1 GPa). The study of deformation and strength characteristics confirmed the feasibility of using up to 30 wt% of recycled polytetrafluoroethylene, obtained by mechanical abrasion, for manufacturing composites with good performance properties. The findings also indicate that the phase composition of the material depends on the method of polymer waste processing, determining the heat resistance and mechanical properties of the obtained self-reinforced polymer composites.