Effect of thermal history on mechanical properties of polyetheretherketone below the glass transition temperature

Abstract

SynopsisTensile properties of polyetheretherketone (PEEK) have been studied at 125, 25, and -100°C for thin films prepared with different therxnal histories. Initial morphology was controlled by rate of cooling from the melt. Amorphous films resulted from quenching the melt, while semicrystalline films were obtained by cooling the melt at Merent rates, or by crystallization of the rubbery amorphous state. The films were characterized using density, X-ray scattering, differential scanning calorimetry, and infrared spectroscopy. Scanning electron microscopy was used to examine fracture surfaces. Degree of crystahity and rate of cooling from the melt affected the tensile properties at all test temperatures. For films with nearly the same degree of crystallinity, those which were more slowly cooled from the melt fractured at the lowest strain. The amorphous films were most tough, drawing to 233% at -100°C and to over 500% at 125OC. Films crystallized from the rubbery amorphous state had streas-strain behavior intermediate between that of the amorphous and melt-crystallized films at all test temperatures. Density measurements on the drawn material indicate that void formation occurs simultaneously with the formation of fibrillar crystals. Necking resulted in density increases for amorphous films, and density decreases for the semicrystalline films.

The influence of a compatibilizer on the thermal and dynamic mechanical properties of PEEK/carbon nanotube composites

“…• C), attributed to the β relaxation [45], associated with local motions of the ketone groups, and an intense sharp peak (at 148.3…”

PEEK biomaterials in trauma, orthopedic, and spinal implants

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Development and characterization of PEEK/carbon nanotube composites

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