Comparing physical properties of PEKK and PEEK

Journal of the Mechanical Behavior of Biomedical Materials, 2011

PEEK Polyetheretherketone Small punch test Crystallinity Mechanical properties Radiopacifier Barium sulphate

Physica B: Condensed Matter, 1992

Polymer Engineering & Science, 2010

This study focuses on the influence of molecular weight on the rheological, thermal, and mechanical behavior of poly(ether-ether-ketone) (PEEK), a semicrystalline high-performance polymer. The results show that the molecular weight of PEEK has significant influence on its rheological, thermal, and mechanical behavior. It was found that PEEK has the unique characteristic of two shear-thinning regions. The shear viscosity and the stress relaxation time of PEEK increase significantly as molecular weight increases. In general, the Cox-Merz rule is valid for all grades of PEEK. As molecular weight increases, the melting temperature of PEEK decreases slightly, but its isothermal and nonisothermal crystallization temperatures drop dramatically. As molecular weight increases, the crystallinity, the crystallization rate, and the magnitude of crystallization activation energy decrease. The crystallization kinetics study indicates that PEEK tends to form spherical crystalline structures, regardless of its molecular weight. As molecular weight increases, the tensile strength at yield, the tensile modulus, and the flexural modulus of PEEK decrease slightly, whereas the tensile strength at break, the tensile strain at break, the modulus of toughness, and the impact strength of PEEK increase significantly.

Journal of materials science. Materials in medicine, 2016

Polyetheretherketone (PEEK) is a polyaromatic semi-crystalline thermoplastic polymer with mechanical properties favorable for bio-medical applications. Polyetheretherketone forms: PEEK-LT1, PEEK-LT2, and PEEK-LT3 have already been applied in different surgical fields: spine surgery, orthopedic surgery, maxillo-facial surgery etc. Synthesis of PEEK composites broadens the physicochemical and mechanical properties of PEEK materials. To improve their osteoinductive and antimicrobial capabilities, different types of functionalization of PEEK surfaces and changes in PEEK structure were proposed. PEEK based materials are becoming an important group of biomaterials used for bone and cartilage replacement as well as in a large number of diverse medical fields. The current paper describes the structural changes and the surface functionalization of PEEK materials and their most common biomedical applications. The possibility to use these materials in 3D printing process could increase the sci...

The Daresbury Synchrotron Radiation Source (SRS) and the Institut Laue-Langevin Neutron Source have been used in studies of the structure of poly (aryl-ether-ether -ketone) (PEEK). Particular emphasis has been placed on achieving complementarity between low and high angle x-ray diffraction and neutron high angle diffraction. These approaches are illustrated by studies of preferential crystallite orientation and super-lattice structure in annealed drawn sheets of PEEK. The impact of the high brilliance of the SRS is illustrated by time-resolved high angle fibre diffraction studies of the drawing and annealing of PEEK.

Macromolecules, 1993

Low molecular weight compounds extracted from PEEK have been identified by I3C NMR, infrared spectroscopy, and size-exclusion chromatography as being cyclic PEEK oligomers. The molecular weight of these cyclic oligomers is larger than 1OOO. Their wide-angle X-ray scattering powder pattern and crystal habit are totally different from those of the polymer. DSC experiments reveal that the oligomers crystallize in two different crystal types. The nucleation rate of these crystals is rather slow because of the large size of the molecules which have to be incorporated in the nucleus. Consequently, moderate cooling rates give rise to glassy oligomers. A very high Tg value is observed for the oligomers, in accordance with their low configurational entropy in the amorphous state due to their cyclic structure.

Macromolecules, 2000

Crystals of monodisperse linear poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4phenylene) (PEEK) oligomers have been reinvestigated by wide-angle and small-angle X-ray scattering and atomic force microscopy (AFM). For the shorter oligomer investigated (containing six phenyl groups), a correlated packing of the chains is observed in the direction of the chain axis, with the formation of crystals being much thicker than the oligomer extended chain length. This results from the alignment of chain ends in planes, as revealed by AFM. A crystal structure is proposed for this oligomer, consistent with both AFM and X-ray diffractometry results. By contrast, the longer oligomer (containing 12 phenyl groups) presents a crystalline morphology consisting of stacks of atomically uncorrelated thin lamellar crystals, whose thicknesses are about the extended chain length computed for the oligomer. This is due to random staggering of the chains along their axes in the crystals, as suggested previously. CP/MAS 13 C solid-state NMR proton spin-lattice relaxation experiments reveal that these morphological differences induce variations in the chain dynamics of the oligomers and confirm that only the longer oligomer can be taken as a good model for a isolated crystal phase. From this study, reference values at room temperature are proposed for the specific mass of a perfect PEEK crystal [1.412(1) g‚cm -3 ] and for the proton spin-lattice relaxation time of such a crystal [3.6(2) s].

JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH, 2019

A number of materials have been proposed for use as biomaterials, including hydrophilic, phase-separated and zwitterionic polymers. The mechanisms responsible for the bio/blood compatibility (bioinertness) of these polymers at the molecular level have not been clearly demonstrated, although many theoretical and experimental efforts have been made to understand these mechanisms. Water interactions have been recognized as fundamental for the biological response to contact with biomaterials. We have proposed the 'intermediate water' concept, in which water clearly exhibits defined peaks for cold crystallization in the differential scanning calorimetry chart and presents a strong peak at 3400 cm À1 in a time-resolved infrared spectrum. We found a localized hydration structure consisting of three hydrated waters in poly(2-methoxyethyl acrylate). We hypothesized that intermediate water, which prevents the proteins and blood cells from directly contacting the polymer surface, or non-freezing water on the polymer surface has an important role in the bio/blood compatibility of polymers. We will provide an overview of the recent experimental progress and a theoretical description of the bio/blood compatibility mechanisms as determined by thermal, spectroscopic and surface force measurements.

Carboxylated polyethersulfone (PES-COOH) was doped with various concentrations of ZnYCdO hybrid metal oxides on the surface of the polymer matrix to produce PES-COOH-ZnYCdO nanocomposites as a thin film. PES-COOH was fabricated by two-steps process: acetylating reaction followed by oxidation reaction, and its structure was investigated using proton nuclear magnetic resonance ( 1 H-NMR) and Fourier-transform infrared (FT-IR) spectroscopy. Then, the fabricated PES-COOH-ZnYCdO nanocomposites (NCs) were characterized using common characterization techniques which include: scanning electron microscope (SEM), X-ray powder diffraction (XRD), FT-IR, thermal analysis, SEM with energy dispersive X-Ray (EDX) spectroscopy and transmission electron microscopy (TEM). FT-IR and XRD analysis confirmed the interactions between carboxylate ions present on the polymer surface metric and the metals that were present as ZnYCdO nanoparticles. Based on values calculated from FT-IR spectra of the PES-COOH-ZnYCdO NCs, the metals and carboxylate ions formed bindentate complexes. Also, the signal peaks of the XRD for ZnYCdO were shifted to a lower degree which also confirmed the interactions between the nanoparticles and PES-COOH. A selective Cd 2+ metal ion sensor was fabricated by coating of a glassy carbon electrode (GCE) with the slurry of PES-COOH-ZnYCdO NCs polymers. The NCs assembled film onto GCE was implemented to successive detection of Cd 2+ metal ion in phosphate buffer medium. To evaluate the sensor analytical performances, a calibration curve has been plotted from current versus concentration of electrolyte (Cd 2+ ion). It is found linear (r 2 = 0.9939) over linear dynamic range (LDR) of 0.1 nM~0.1 mM concentration of Cd 2+ ion by electrochemical approach. The sensitivity and detection limit (DL) are 5.4589 μAμM −1 cm −2 and 17.39 ± 0.87 pM respectively were calculated from the slope of calibration plot. Therefore, the resultant Cd 2+ sensor shows good sensitivity, reproducibility with high accuracy, wider dynamic range, short response time, very lower detection limit and long-term stability with similar performances. Journal of Polymer Research (2018) 25: 262 https://doi.org/10.1007/s10965-018-1643-y PES-COOH PES-COOH-ZnYCdO (2%) PES-COOH-ZnYCdO (5%) PES-COOH-ZnYCdO (10%) PES-COOH-ZnYCdO (20%) 3401.2 262 Page 6 of 15 J Polym Res (2018) 25: 262 Fig. 2 FT-IR spectra of (a) PES, PES-COCH 3 , and PES-COOH and (b) PES-COOH and PES-COOH-ZnYCdO (2%), PES-COOH-ZnYCdO (5%), PES-COOH-ZnYCdO (10%), and PES-COOH-ZnYCdO (20%)