Shear exfoliation of graphite into graphene nanoflakes directly within polyetheretherketone and a spectroscopic study of this high modulus, lightweight nanocomposite

Lynch-Branzoi, Jennifer; Ashraf, Ali; Tewatia, Arya; Taghon, Meredith; Wooding, Jamie P.; Hendrix, Justin; Kear, B. H.; Nosker, Thomas

doi:10.1016/j.compositesb.2020.107842

Cited by 28 publications

(21 citation statements)

References 40 publications

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“…This is probably the influence of the melt processing of the composites. The exfoliation of graphite in a molten polymer under the influence of high-shear stresses formed during melt compounding has already been emphasized for several polymers [ 15 , 38 ].…”

Section: Resultsmentioning

confidence: 99%

Control of Dielectric and Mechanical Properties of Styrenic Block Copolymer by Graphite Incorporation

et al. 2022

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The structure–property relationship of dielectric elastomers, as well as the methods of improving the control of this relationship, has been widely studied over the last few years, including in some of our previous works. In this paper, we study the control, improvement, and correlation, for a significant range of temperatures, of the mechanical and dielectric properties of polystyrene-b-(ethylene-co-butylene)-b-styrene (SEBS) and maleic-anhydride-grafted SEBS (SEBS-MA) by using graphite (G) as filler in various concentrations. The aim is to analyze the suitability of these composites for converting electrical energy into mechanical energy or vice versa. The dielectric spectroscopy analysis performed in the frequency range of 10 to 1 MHz and at temperatures between 27 and 77 °C emphasized an exponential increase in real permittivity with G concentration, a low level of dielectric losses (≈10−3), as well as the stability of dielectric losses with temperature for high G content. These results correlate well with the increase in mechanical stiffness with an increase in G content for both SEBS/G and SEBS-MA/G composites. The activation energies for the dielectric relaxation processes detected in SEBS/G and SEBS-MA/G composites were also determined and discussed in connection with the mechanical, thermal, and structural properties resulting from thermogravimetric analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses.

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Section: Resultsmentioning

confidence: 99%

Control of Dielectric and Mechanical Properties of Styrenic Block Copolymer by Graphite Incorporation

et al. 2022

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“…Graphite with part A and part B was mixed in a 1:1 ratio through simple hand mixing and highspeed planetary shear mixing techniques (two different procedures result in different dispersion in polymer composites). Another mixing of a higher percentage of graphite (40% G) in Eco ex part A and part B both was done in a Randcastle batch mixer, where bulk graphite is exfoliated to graphene via shear exfoliation 31 (two samples were prepared, rst sample is 100 rpm & 3 minutes of mixing, second one is 100 rpm & 10 minutes of mixing). Simple hand mixing, planetary mixing (mixed at 2000 rpm for 1 minute) and batch mixing samples will be referred to as 2.5/5/7.5/10% G Hand, 2.5/5/7.5/10% G Planetary, and 40% G Batch throughout this manuscript respectively.…”

Section: Methodsmentioning

confidence: 99%

Automatic Dispersion, Defect, Curing, and Thermal Characteristics Determination of Polymer Composites using Micro-Scale Infrared Thermography and Machine Learning Algorithm

Rahman

Ashraf

2022

Preprint

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Infrared thermography is a non-destructive technique that can be exploited in many fields including polymer composite investigation. Based on emissivity and thermal diffusivity variation, components, defects, and curing state of the composite can be identified. However, manual processing of thermal images that may contain significant artifacts, is prone to erroneous component and property determination. In this study, thermal images of different graphite/graphene-based polymer composites fabricated by hand, planetary, and batch mixing techniques were analyzed through an automatic machine learning model. Filler size, shape, and location can be identified in polymer composites and thus, the dispersion of different samples was quantified with a resolution of ~ 20 µm despite having artifacts in the thermal image. Thermal diffusivity comparison of three mixing techniques was performed for 40% graphite in the elastomer. Batch mixing demonstrated superior dispersion than planetary and hand mixing as the dispersion index (DI) for batch mixing was 0.07 while planetary and hand mixing showed 0.0865 and 0.163 respectively. Curing was investigated for a polymer with different fillers (PDMS took 500s while PDMS-Graphene and PDMS Graphite Powder took 800s to cure), and a thermal characteristic curve was generated to compare the composite quality. Therefore, the above-mentioned methods with machine learning algorithms can be a great tool to analyze composite both quantitatively and qualitatively.

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“…In addition, the neat PEEK displays peaks at 2θ = 18.82°, 2θ = 20.56°, 2θ = 22.29°, and 2θ = 28.68° belonging to the 110, 111, 200, and 211 planes of the orthorhombic PEEK structure, respectively. The XRD pattern of the hot pressed sample also exhibits a sharp broad peak at the same angle of 2θ = 26.55° as graphite due to the beginning of crystallization [29].…”

Section: Xrd Analysismentioning

confidence: 98%

Hot pressed PEEK/Graphite thin film laminate composites: Thermal properties and mechanical behavior

Sariyev

Abdikadyr

Baitikenov

et al. 2023

Preprint

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This work studies high-performance laminate composite materials made of graphite and poly(ether-ether-ketone) (PEEK). The composites were fabricated using a hot press method at a temperature below 310°C, and their structural, thermal, and mechanical properties were evaluated and discussed. SEM images of the laminate cross-section indicated a solid interfacial interaction between PEEK and graphite due to the high joining load. Thermogravimetric analysis (TGA) results showed that 3-layered PEEK/graphite/PEEK (PGP) and 5-layered PEEK/graphite/PEEK/graphite/PEEK (PG)2P composites had better thermal stability at high temperatures compared to neat PEEK. The mechanical properties tests showed that PGP had a higher Ultimate Tensile Strength (UTS) by 52% compared to neat graphite. However, adding another layer of graphite (PG)2P caused a decrease in UTS by 9.6% due to the higher volume fraction of graphite. The nanoindentation tests confirmed these findings: Young's modulus increased from 1.64 to 2.58 GPa, and the hardness increased from 0.164 to 0.178 GPa for PGP and (PG)2P, respectively. Additionally, XRD analysis indicated that the crystallinity of fabricated composites increased by 35.5% compared with pristine PEEK. The present study confirms that using PEEK and graphite sheets in composite fabrication through hot pressing improves thermal and mechanical properties.

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Shear exfoliation of graphite into graphene nanoflakes directly within polyetheretherketone and a spectroscopic study of this high modulus, lightweight nanocomposite

Cited by 28 publications

References 40 publications

Control of Dielectric and Mechanical Properties of Styrenic Block Copolymer by Graphite Incorporation

Control of Dielectric and Mechanical Properties of Styrenic Block Copolymer by Graphite Incorporation

Automatic Dispersion, Defect, Curing, and Thermal Characteristics Determination of Polymer Composites using Micro-Scale Infrared Thermography and Machine Learning Algorithm

Hot pressed PEEK/Graphite thin film laminate composites: Thermal properties and mechanical behavior

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