Determination of matrix crystallinity of composites by X‐ray diffraction

Spahr, Douglas E.; Schultz, J. M.

doi:10.1002/pc.750110402

Cited by 13 publications

(7 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Assuming a two phase (crystalline and amorphous) model for PEEK, the crystalline fraction can be evaluated. In order to simulate the broad halo coming from a fully amorphous sample, different model backgrounds from the literature were tried [39][40][41]. In Figure 2, one of the plausible backgrounds is represented.…”

Section: X-ray Diffraction Measurementsmentioning

confidence: 99%

Tribological and mechanical properties of graphene nanoplatelet/PEEK composites

Puértolas

Castro

Morris

et al. 2019

Carbon

164

View full text Add to dashboard Cite

Poly(ether ether ketone) (PEEK) is a relevant thermoplastic in industry and in the biomedical sector. In this work, the lubricant capability of graphene nanoplatelets (GNPs) is used for improving the PEEK wear properties. Nanocomposites were prepared by solvent-free meltblending and injection molding at various compositions between 1 and 10 wt. % of GNPs. The Raman G band shows a progressive increment proportional to the bulk GNP percentage. From calorimetric data, the polymer matrix structure is interpreted in terms of a 3-phase model, in which the crystalline phase fluctuates from 39 to 34% upon GNP addition. Thermal conductivity varies in accordance with the polymer crystallinity. Tensile and flexural tests show a progressive increase in the modulus, as well as a decrease in the fracture strength and the work of fracture. Most important, the composite surface undergoes a substantial improvement in hardness (60%), together with a decrease in the coefficient of friction (-38%) and a great reduction in the wear factor (-83%). Abrasion and fatigue wear mechanisms are predominant at the lowest and highest GNP concentrations respectively. In conclusion, GNPs are used without any chemical functionalization as the filler in PEEK-based materials, improving the surface hardness and the tribological properties.

show abstract

Section: X-ray Diffraction Measurementsmentioning

confidence: 99%

Tribological and mechanical properties of graphene nanoplatelet/PEEK composites

Puértolas

Castro

Morris

et al. 2019

Carbon

164

View full text Add to dashboard Cite

show abstract

“…The determination of the DOC thus involves the separation of the peaks scattered by the amorphous phase and the peak reflected by the crystalline phase, which can be very cumbersome (6). A fully amorphous template of the polymer can be first prepared and its XRD peak measured to be used as a reference for the evaluation (7) in Eq 1.…”

Section: Doc Measurementmentioning

confidence: 99%

“…POLYMER COMPOSITES, DECEMBER 1995, Vol. 16, No 6. glass samples with similar treatment conditions are shown in Figs.…”

mentioning

confidence: 98%

X‐ray diffraction analysis technique for determining the polymer crystallinity in a polyphenylene sulfide composite

1995

View full text Add to dashboard Cite

The degree of crystallinity in polymers is commonly known to significantly affect their mechanical properties. To that extent, it also affects the mechanical properties—such as compression, buckling, and creep—of thermoplastic composites that are matrix dominant. For this reason, it is important that the degree of crystallinity in a thermoplastic composite be precisely determined, which is the focus of this paper. In particular, the crystallinity for a thermoplastic poly(phenylene sulfide) composite reinforced with glass fibers is determined using an X‐ray diffraction technique (XRD). While conventional methods have been adopted for homogeneous phases, a modified method has been adopted to account for the heterogeneous nature of the composite. The results have also been compared with results obtained using DSC and DMA techniques, indicating that the XRD method yielded lower values, which are considered to be more accurate. This was attributed to the absence of a recrystallization effect in the XRD method, which was unavoidable in the other two methods.

show abstract

“…The amorphous phase has a broad peak at 20 = 19-20" and the carbon fibers have a peak at 20 = 25". 22 Comparing the X-ray spectra of the PEEK composite consolidated at various cooling rates (Fig. 6a) shows that at slower rates (I"C/min) the area of the crystalline peaks was the largest when compared with the amorphous peak, meaning that the degree of crystallinity increases with reducing cooling rate.…”

Section: Effect Of Crystallinitymentioning

confidence: 97%

Preadhesion Laser Surface Treatment of Carbon Fiber Reinforced PEEK Composite

Rotel

Zahavi

Buchman

et al. 1995

The Journal of Adhesion

View full text Add to dashboard Cite

An excimer UV laser (193 nm) was used for preadhesion surface treatment of PEEK (polyetheretherketone) composite. This method presented an alternative to other limited and polluting conventional surface treatment methods. Experimental results indicated that laser preadhesion treatment significantly improved the shear and tensile adhesion strength of structural epoxy FM 300 2K bonded PEEK composite adherends compared with untreated and Sic blasted substrates. Best results were obtained with laser energies of0.18 or 1 J/P.cm.' Shear strength of laser-treated joints was improved by 450% compared with that of untreated PEEK composite and by 200% compared with Sic-blasted pretreatment at ambient and at extreme temperatures. An order of magnitude of improvement was found in the tensile strength-of laser-treated PEEK composite in a sandwich structure compared with non-treated or abraded sandwich joints. The mode of failure changed from adhesive to cohesive as the number of pulses or laser energy increased during treatment. The latter phenomenon was correlated with surface cleaning as revealed by XPS, with morphology changes as revealed by scanning electron microscopy, and by chemical modification as indicated by FTIR and XPS. The bulk of the PEEK composite adherend was not damaged by the laser irradiation during treatment as indicated by the identical flexural strength before and after laser treatment. It can be concluded that the excimer laser has a potential as a precise, clean and simple preadhesion surface treatment for PEEK composite.

show abstract

Determination of matrix crystallinity of composites by X‐ray diffraction

Cited by 13 publications

References 7 publications

Tribological and mechanical properties of graphene nanoplatelet/PEEK composites

Tribological and mechanical properties of graphene nanoplatelet/PEEK composites

X‐ray diffraction analysis technique for determining the polymer crystallinity in a polyphenylene sulfide composite

Preadhesion Laser Surface Treatment of Carbon Fiber Reinforced PEEK Composite

Contact Info

Product

Resources

About