3D Printable All-Polymer Epoxy Composites

• Published in: ACS applied polymer materials 2021-11, Vol.3 (11), p.5559-5567
• Main Authors: Shen, Liyang, Wang, Tung-ping, Lee, Ting-Han, Forrester, Michael, Becker, Andrew, Torres, Sabrina, Pearson, Connor, Cochran, Eric W
• Format: Article
• Language: English
• Subjects: 3D printing; block copolymer; composites; epoxy; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; toughening
• ISSN: 2637-6105; 2637-6105
• DOI: 10.1021/acsapm.1c00889

Herein, 3D printable polymer-toughened epoxy resin composites are reported. Epoxy resins are widely used due to their excellent properties, such as thermal and chemical stability. However, their applications are limited by traditional mold-based manufacturing and their high brittleness. Mixtures of homopolymers, diblock copolymers, and triblock copolymers composed of poly­(phenylene ether), poly­(styrene), poly­(methyl methacrylate), and poly­(ethylene oxide) that self-assemble into micelles in the uncured resin are employed, providing a balance of structure, creep resistance, and flowability that enables 3D printing processing techniques and retention of shape from the time of printing throughout the cured state. The precured ink is solid at room temperature and has strong shear-thinning behavior at elevated temperature for printing. As the printed parts cure, the polymer morphology evolves via reaction-induced phase separation to yield finished composites with enhanced mechanical properties, including a 40% increase in the impact strength compared to the neat epoxy, without compromising thermal properties.