Comparative study of the crystallization behavior and morphologies of carbon and glass fiber reinforced poly(ether ether ketone) composites

Abstract

This work aims to perform a systematic investigation on the crystallization behavior and morphologies of carbon and glass fiber reinforced PEEK. The nonisothermal and isothermal crystallization behavior was investigated by differential scanning calorimetry (DSC). The resultant morphologies were assessed by wide angle X-ray diffraction (WAXD), small angle X-ray scattering (SAXS), and polarized optical microscopy (POM) to provide details on spherulitic level, crystalline structure at unit cell, and lamellar levels. It was found that the crystallization ability of carbon fiber filled PEEK was better than that of neat PEEK, while the behavior of glass fiber filled PEEK was in an opposite trend. The incorporation of carbon fiber (or glass fiber) led to a looser packing of the unit cell or a less crystal perfection of PEEK but did not change its crystal form as well as its long period of lamellae. The isothermal crystallization kinetics was analyzed by the Avrami model, suggesting that the crystallization mechanism of carbon fiber filled PEEK was different from that of neat PEEK and its glass fiber filled composites. Nevertheless, the POM results showed that fiber-induced transcrystallization in PEEK matrix was not evidenced for either carbon or glass fiber filled PEEK. Finally, the effect of carbon and glass fiber on the crystallization of PEEK matrix was discussed to some extent.

Post-weld annealing of friction stir welded carbon fiber reinforced low-melt polyaryletherketone

“…Incorporation of fibers does not change the crystal form of PEEK. 16,46 Therefore, shifts exclusive to the polymer peaks in welded specimens compared to the non-welded base material indicates that FSW slightly increases the unit cell spacing, resulting in a reduction in crystal packing.…”

“…15 The formation of a transcrystalline region, or crystals oriented along the fiber/matrix interface, promotes improved interfacial shear strength between the polymer and fibers. 16 Low crystallinity can be beneficial under circumstances that requires ductility. However, low crystallinity increases permeability in the polymer that allows for diffusion of gases.…”

Effect of Fiber Type and Content on Surface Quality and Removal Mechanism of Fiber-Reinforced Polyetheretherketone in Ultra-Precision Grinding

“…In general, the physical properties of the material affected the amount of the deformation of the surface material during grinding, and the material with high plasticity swelled more on both sides of the grooves than the material with weak plasticity. On the one hand, adding carbon fibers to PEEK could increase the crystallinity of the PEEK matrix [ 34 ], and as the crystallinity of PEEK increased, the tensile strength of PEEK and the modulus would increase and the plasticity capacity would weaken [ 35 ]. Therefore, adding carbon fibers could effectively reduce the degree of material swelling on both sides of the PEEK matrix grooves and improve the grinding surface quality.…”

Bottom‐up analysis framework for the continuous multidirectional carbon fiber‐reinforced PEEK composite laminates

“…This behavior is primarily attributed to the following three factors. Firstly, the carbon fibers in the composites not only accelerate the crystallization behavior of PEEK but also promote the formation of transcrystalline regions around the carbon fibers, 70,71 leading to a higher modulus around the fibers. [72][73][74] Secondly, the FE-RVE model established in this study does not consider the influence of interfacial phases.…”