| Abstract Scope |
Poly(tetrafluoroethylene) (PTFE) is high-performance polymer that offers unique properties such as chemical resistance and thermal stability. However, these valuable properties make PTFE challenging to process. Prior efforts in additive manufacturing of PTFE via vat photopolymerization or material extrusion of a colloidal suspension yielded 3D parts that were brittle and/or weak. In this work, the authors test the hypothesis that a pressure-assisted post-processing strategy (e.g., pressure pre-treatment before thermal post-processing) can further eliminate defects, improve part densification, and enhance mechanical properties of printed PTFE parts. Scanning electron microscopy confirms that the pressure-assisted post-process facilitates polymer coalescence and eliminates microvoids, thus enabling fabrication of porosity-free solid parts. These samples also exhibited significant enhancement in mechanical performance, including elongation at break (936% increase compared to pressure-free post-processing), Young’s modulus (113% increase), tensile strength (68% increase), yield stress (40% increase), and toughness (3320% improvement). |