The mechanics of reinforcement of polymers by graphene nanoplatelets

Young, Robert J.; Liu, Mufeng; Kinloch, Ian A.; Li, Suhao; Zhao, Xin; Vallés, Cristina; Papageorgiou, Dimitrios G.

doi:10.1016/j.compscitech.2017.11.007

Cited by 265 publications

(195 citation statements)

References 32 publications

Supporting

Mentioning

185

Contrasting

Order By: Relevance

“…Although the tensile testing results revealed good levels of reinforcement for the PMMA-NH-GNPs/PMMA composites (considerably superior than those found for the non-modified GNPs based composites), the effective modulus found here for this filler was still much lower than the 350 GPa theoretically predicted for the mechanical modulus of GNPs [32,33].…”

contrasting

confidence: 68%

“…Young et al [32] recently developed a theory which explains why it is not possible to realise the promised 1 TPa or 350 GPa moduli for graphene or GNPs, respectively, in low modulus polymeric matrices. This theory predicts that the Young's modulus of a nanocomposite will be independent of the Young's modulus of the nanofiller, and highlights the importance of three structural parameters: (i) aspect ratio of the nanofiller, (ii) orientation of the nanofiller, and (iii) strength of the interface with the matrix (the theory shows that a strong nanofillermatrix interface leads to good stress-transfer and hence better reinforcement than a weak interface).…”

mentioning

confidence: 99%

See 1 more Smart Citation

PMMA-grafted graphene nanoplatelets to reinforce the mechanical and thermal properties of PMMA composites

Vallés

Papageorgiou

Lin

et al. 2020

Carbon

Self Cite

View full text Add to dashboard Cite

In order to realise the potential of graphene nanocomposites it is vital to control the degree of dispersion and achieve a strong graphene/polymer interface. Herein, we developed a facile 'grafting to' functionalisation approach for graphene nanoplatelets. NH2-terminated graphene nanoplatelets (NH2-GNPs) prepared by a diazonium coupling were used as a 'platform' to covalently graft PMMA chains to the surface of graphene through an amidation between the -NH2 groups and PMMA chains (PMMA-NH-GNPs). A degree of PMMA grafting of ~3.8 wt.% (one chain per ~40 carbon atoms) was found to both improve the dispersion of the GNPs in a PMMA matrix and give strong graphene/polymer interfaces compared to asprovided GNPs. Thus, 2 wt.% of PMMA-NH-GNPs in PMMA was found to increase the elastic modulus, strength and strain at break of PMMA, whereas the incorporation of unmodified GNPs showed poor levels of reinforcement at all loadings. Furthermore, Tg and Td of PMMA were increased by 15 °C and 29 °C, respectively, by adding 5 wt.% of PMMA-NH-GNPs, whereas incorporating unmodified GNPs led to smaller increases. This work offers the possibility of controlling the properties of graphene/polymer composites through * Corresponding authors. cristina.valles@manchester.ac.uk; Tel: +44(0)161 306 1454 ian.kinloch@manchester.ac.uk; Tel: +44(0)161 306 3615 2 chemically tuning the graphene/polymer interface, which will have broad implications in the field of nanocomposites.

show abstract

contrasting

confidence: 68%

mentioning

confidence: 99%

PMMA-grafted graphene nanoplatelets to reinforce the mechanical and thermal properties of PMMA composites

Vallés

Papageorgiou

Lin

et al. 2020

Carbon

Self Cite

View full text Add to dashboard Cite

show abstract

“…6b values of E f = 14 GPa and E eff = 26 GPa were determined for the nanofiller used here. Although the tensile testing results revealed good levels of reinforcement for these GNPs epoxy composites, the modulus found for these nanoplatelets is much lower than their estimated 300 GPa value [22]. For the GNP/epoxy-Oven composites, the stress and strain at break (Fig.…”

Section: Mechanical Properties Of the Gnp/epoxy Compositesmentioning

confidence: 82%

Electrically conductive GNP/epoxy composites for out-of-autoclave thermoset curing through Joule heating

Xia

Zeng

et al. 2018

Composites Science and Technology

Self Cite

View full text Add to dashboard Cite

The development of scalable Out-of-Autoclave (OoA) in-situ thermoset curing methods are required to overcome important drawbacks related to the autoclave-based processing methods typically used in industry. The incorporation of graphene, an electrothermal carbon nanomaterial with the ability to transform electric energy into heat through Joule heating, emerges as a promising route to replace the conventional processing methods. In this work the electrical behaviour of both uncured and oven cured GNPs/epoxy composites with loadings of up to 10 wt.% were evaluated and electrical percolation thresholds were established for both. Above the critical loading found for oven cured materials (~ 8.5 wt.%) the electrically conducting networks of GNPs formed in the matrix showed the ability to act as integrated nanoheaters when an electric current was passed through them, successfully curing the composites by Joule heating. Composites prepared by this OoA curing method (as an alternative to the traditional oven based one) at 10 wt.% loading of GNPs were also prepared and compared to the oven cured ones. They showed more compact composite 2 structures, with less microvoids and a preferred orientation of the GNPs in the matrix relative to the oven cured material at identical loading, as revealed by electron microscopy and polarized Raman spectroscopy, respectively. This microstructure and anisotropy induced by the electrically-induced (i.e. OoA) cure led to GNPs/epoxy composites with superior electrical and mechanical properties (revealed by tensile testing). The well-distributed GNP nanoparticles acting as nanoheaters integrated in a thermosetting matrix, in combination with excellent mechanical and electrical performances achieved for the overall graphene/epoxy composites and the simplicity associated to the method, should open the door to novel industrial applications.

show abstract

“…Therefore, the stress at the laser-focused point of the nanoplatelet is higher than the average stress along the flakes, leading to higher filler modulus acquired by Raman measurements (ER) than the filler modulus determined by tensile testing (Ef) [21].…”

Section: Raman 2d Band Shiftmentioning

confidence: 99%

Modelling mechanical percolation in graphene-reinforced elastomer nanocomposites

Liu

Kinloch

Young

2019

Composites Part B: Engineering

Self Cite

View full text Add to dashboard Cite

Graphene is considered an ideal filler for the production of multifunctional nanocomposites; as a result, considerable efforts have been focused on the evaluation and modeling of its reinforcement characteristics. In this work, we modelled successfully the mechanical percolation phenomenon, observed on a thermoplastic elastomer (TPE) reinforced by graphene nanoplatelets (GNPs), by designing a new set of equations for filler contents below and above the percolation threshold volume fraction (Vp). The proposed micromechanical model is based on a combination of the well-established shear-lag theory and the rule-of-mixtures and was introduced to analyse the different stages and mechanisms of mechanical reinforcement. It was found that when the GNPs content is below Vp, reinforcement originates from the inherent ability of individual GNPs flakes to transfer stress efficiently. Furthermore, at higher filler contents and above Vp, the nanocomposite materials displayed accelerated stiffening due to the reduction of the distance between adjacent flakes. The model derived herein, was consistent with the experimental data and the reasons why the superlative properties of graphene cannot be fully utilized in this type of composites, were discussed in depth.2

show abstract

The mechanics of reinforcement of polymers by graphene nanoplatelets

Cited by 265 publications

References 32 publications

PMMA-grafted graphene nanoplatelets to reinforce the mechanical and thermal properties of PMMA composites

PMMA-grafted graphene nanoplatelets to reinforce the mechanical and thermal properties of PMMA composites

Electrically conductive GNP/epoxy composites for out-of-autoclave thermoset curing through Joule heating

Modelling mechanical percolation in graphene-reinforced elastomer nanocomposites

Contact Info

Product

Resources

About