Development and characterization of PEEK/carbon nanotube composites

Abstract

New poly(ether ether ketone) (PEEK) based composites have been fabricated by the incorporation of single-walled carbon nanotubes (SWCNTs) using melt processing. Their structure, morphology, thermal and mechanical properties have been investigated. Scanning electron microscopy observations demonstrated a more uniform distribution of the CNTs for samples prepared following a processing route based on polymer ball milling and CNT dispersion in ethanol media. Thermogravimetric analysis indicated a remarkable improvement in the thermal stability of the matrix by the incorporation of SWCNTs. Differential scanning calorimetry showed a decrease in the crystallization temperature with increasing SWCNT content, whilst no significant changes were observed in the melting of the composites. The

Influence of carbon nanotubes on the thermal, electrical and mechanical properties of poly(ether ether ketone)/glass fiber laminates

“…2b corresponds to a region between fiber tows of the laminate incorporating 1.0 wt% non-wrapped arc-SWCNTs, showing the existence of small CNT agglomerates (see the circle marked on the image). As can be visualized in the inset, the aggregates form a highly entangled interconnected structure, with SWCNT bundle diameters in the range 30-60 nm, values similar to those found previously for PEEK/arc-SWCNT composites [25]. These SWCNT aggregates (bigger than 2 lm) envelop the fiber tows but do not penetrate into them.…”

“…Arc and laser-grown SWCNTs were synthesized following the procedures reported in our previous works [25,26]. The compatibilizing agent poly(1-4-phenylene ether-ether sulfone), PEES (M w $ 38,000 g/ mol, T g = 192°C, d 25°C = 1.38 g/cm 3 ), was provided by Sigma-Aldrich in pellet form.…”

“…To extend its structural applications, several studies have been devoted to enhance the properties of PEEK via incorporation of fillers such as glass fibers [20][21][22] and carbon fibers [23,24]. Recently, our group has demonstrated that the properties of this high-performance material can be significantly enhanced by the addition of single-walled carbon nanotubes (SWCNTs) [25,26]. In particular, the addition of small amounts of SWCNTs wrapped in compatibilizing agents such as polysulfone, an amorphous thermoplastic miscible with and structurally similar to PEEK, leads to a remarkable increase in the storage and Young's modulus, T g and degradation temperatures of the matrix [27,28].…”

High performance PEEK/carbon nanotube composites compatibilized with polysulfones-I. Structure and thermal properties

“…It is worthy to notice that the average bundle diameters of the SWCNTs dispersed in PSF and PEES (Table 1) are smaller than the values obtained from SEM images of the non-wrapped SWCNTs [17]. This indicates that the addition of the polysulfones leads to a significant CNT disentanglement and debundling, and thereby confirms their efficiency as compatibilizing agents.…”

“…Over the last decades many studies have been reported on the structural [11], mechanical [12] and thermal [13] characterization of this linear aromatic polymer, albeit only a few papers deal with such composites made of a PEEK matrix; the most relevant are those published by Shaffer et al [14], working with vapor-grown carbon nanofiber/PEEK composites, Deng et al [15], dealing with multi-walled carbon nanotube (MWCNT)/PEEK nanocomposites, and Song et al [16], who prepared sandwich like SWCNT paper/PEEK composites. Recently, our group reported the synthesis and characterization of PEEK/SWCNT composites [17]. We have developed strategies to efficiently incorporate the nanotubes in the PEEK matrix.…”