Room temperature extrusion 3D printing of polyether ether ketone using a stimuli-responsive binder

TitleRoom temperature extrusion 3D printing of polyether ether ketone using a stimuli-responsive binder
Publication TypeJournal Article
Year of Publication2019
AuthorsLee, CU, Vandenbrande, J, Goetz, AE, Ganter, MA, Storti, DW, Boydston, AJ
JournalAdditive Manufacturing
Date PublishedAug
ISBN Number2214-8604

write technology. The room-temperature extrusion printing method was enabled by a unique formulation comprised of commercial PEEK powder, soluble epoxy-functionalized PEEK (ePEEK), and fenchone. This combination formed a Bingham plastic that could be extruded using a readily available direct-ink write printer. The initial green body specimens were strong enough to be manipulated manually after drying. After printing, thermal processing at 230 degrees C resulted in crosslinking of the ePEEK components to form a stabilizing network throughout the specimen, which helped to preclude distortion and cracking upon sintering. A final sintering stage was conducted at 380 degrees C. The final parts were found to have excellent thermal stability and solvent resistance. The T-g of the product specimens was found to be 158 degrees C, which is 13 degrees C higher than commercial PEEK as measured by DSC. Moreover, the thermal decomposition temperature was found to be 528 degrees C, which compares well against commercial molded PEEK samples. Chemical resistance in trifluoroacetic acid and 8 common organic solvents, including CH2Cl2 and toluene, were also investigated and no signs of degradation or weight changes were observed from parts submerged for 1 week in each solvent. Test specimens also displayed desirable mechanical properties, such as a Young's modulus of 2.5 GPa, which corresponds to 63% of that of commercial PEEK (reported to be 4.0 GPa).