Improvement in Mechanical Properties of 3D‐Printed PEEK Structure by Nonsolvent Vapor Annealing

Abstract

AbstractThe broad applications of 3D‐printed poly‐ether‐ether‐ketone (3D‐PEEK) structures are largely hampered by their inadequate mechanical properties that can be improved by post treatments. At present, thermal annealing is generally used to improve the mechanical properties of 3D‐PEEK. However, it cannot simultaneously improve strength and ductility. Here, a cost‐effective postprocessing method is developed to improve the mechanical properties of 3D‐PEEK, based on annealing in nonsolvent vapor at room temperature. The annealing in nonsolvent vapor at room temperature simultaneously improves the strength, ductility, and fracture energy of as‐printed 3D‐PEEK by 22.6%, 151.3%, and 109.1%, respectively. The improved mechanical properties are attributed to enhanced interfacial bonding, increased crystallinity, decreased pinhole defects, and stress relaxation in the 3D‐PEEK. Moreover, the annealing in both polar solvents (such as acetone and chloroform) and nonpolar solvents (such as n‐hexane) are demonstrated to be effective for improving the mechanical properties of 3D‐PEEK. The nonsolvent vapor‐annealed 3D‐PEEK can thus have potential applications in the fields of medical implants, automotive, aerospace, and more.