Equal channel angular extrusion of ultra-high molecular weight polyethylene.
Ultra-high molecular weight polyethylene (UHMWPE), a common bearing surface in total joint arthroplasty, is subject to material property tradeoffs associated with conventional processing techniques. For orthopaedic applications, radiation-induced cross-linking is used to enhance the wear resistance of the material, but cross-linking also restricts relative chain movement in the amorphous regions and hence decreases toughness. Equal Channel Angular Extrusion (ECAE) is proposed as a novel mechanism by which entanglements can be introduced to the polymer bulk during consolidation, with the aim of imparting the same tribological benefits of conventional processing without complete inhibition of chain motion. ECAE processing at temperatures near the crystalline melt for UHMWPE produces (1) increased entanglements compared to control materials; (2) increasing entanglements with increasing temperature; and (3) mechanical properties between values for untreated polyethylene and for cross-linked polyethylene. These results support additional research in ECAE-processed UHMWPE for joint arthroplasty applications.
Thayer School of Engineering at Dartmouth College, 14 Engineering Drive, Hanover, NH 03755, United States. Electronic address: Steven.D.Reinitz.TH@Dartmouth.edu.
Steven D
SD
Reinitz
Thayer School of Engineering at Dartmouth College, 14 Engineering Drive, Hanover, NH 03755, United States.
Alexander J
AJ
Engler
Thayer School of Engineering at Dartmouth College, 14 Engineering Drive, Hanover, NH 03755, United States.
Evan M
EM
Carlson
Thayer School of Engineering at Dartmouth College, 14 Engineering Drive, Hanover, NH 03755, United States.
Douglas W
DW
Van Citters
D001178:Arthroplasty; D006801:Humans; D011095:Polyethylenes / Q000737:chemistry*
D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene
DMA; DSC; ECAE; Entanglements; UHMWPE