title: Porous poly-ether ether ketone (PEEK) manufactured by a novel powder route using near-spherical salt bead porogens: characterisation and mechanical properties.
abstract: Porous PEEK structures with approximately 85% open porosity have been made using PEEK-OPTIMA® powder and a particulate leaching technique using porous, near-spherical, sodium chloride beads. A novel manufacturing approach is presented and compared with a traditional dry mixing method. Irrespective of the method used, the use of near-spherical beads with a fairly narrow size range results in uniform pore structures. However the integration, by tapping, of fine PEEK into a pre-existing network salt beads, followed by compaction and "sintering", produces porous structures with excellent repeatability and homogeneity of density; more uniform pore and strut sizes; an improved and predictable level of connectivity via the formation of "windows" between the cells; faster salt removal rates and lower levels of residual salt. Although tapped samples show a compressive yield stress >1 MPa and stiffness >30 MPa for samples with 84% porosity, the presence of windows in the cell walls means that tapped structures show lower strengths and lower stiffnesses than equivalent structures made by mixing.
authors.affiliation: Manufacturing Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: Abdur R
authors.initials: AR
authors.lastname: Siddiq
authors.affiliation: Manufacturing Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, UK. Electronic address: andrew.kennedy@nottingham.ac.uk.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Kennedy
mesh_terms: D001577:Benzophenones; D001672:Biocompatible Materials / Q000737:chemistry; D019245:Compressive Strength; D007659:Ketones / Q000737:chemistry*; D008422:Materials Testing / Q000379:methods; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers; D016062:Porosity; D011208:Powders / Q000737:chemistry*; D019736:Prostheses and Implants; D012492:Salts / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D013314:Stress, Mechanical
chemical_list: D001577:Benzophenones; D001672:Biocompatible Materials; D007659:Ketones; D011108:Polymers; D011208:Powders; D012492:Salts; C063834:polyetheretherketone; D011092:Polyethylene Glycols; D012965:Sodium Chloride
keywords: Characterisation; Compressive strength; PEEK; Porosity; Powder processing