Effects of swelling on the effective mechanical and electrical properties of a carbon black-filled polymer

Mechanical properties of heterogeneous systems based on carbon black (CB) filled semi-crystalline ethylene butyl acrylate (EBA) copolymer nanocomposites are characterized using nano-indentation technique. The size effect and CB content dependence on the deformation behavior at room temperature were investigated. The phenomenology for hardness response (H) indicates a typical enhancement of the H when the indentation depth (h) decreases as for the usual elastomeric materials. All H-h curves, fitted according to the Meyer's empirical power law and Franck elasticity model, highlight the so-called length-scale-dependent deformation. Similar trend is observed for the elastic modulus. Furthermore, it is evidenced that the increases of CB content increases the mechanical properties of composites, that is, hardness and elastic modulus. This behavior can be mainly related, on the one hand, to the change of the meso-structure, formed by the interconnected network of polymer and the aggregates of CB particles and to the nature of the polymer matrix, on the other hand. The mechanical properties characterized from micro and submicron indentations were compared to that characterized at macroscopic scale to highlight the possible correlations between the two scales. This investigation can interest many applications of polymer composites for rubber technology such as tires industry, soft robotic, and adhesives.

Section: Methodssupporting

confidence: 61%

Nano‐indentation for probing mechanical properties of nanocomposites based on ethylene butyl acrylate copolymer and carbon black

Bentoumi¹,

Mdarhri

Montagne

et al. 2019

“…38 Fitting the stress-strain curve with the 2-parameter MR model is not appropriate to represent the stress-strain data of CB filled EBA samples as reported elsewhere. 30 Because each curve is characterized by two inflection points, we find that the 5-parameter model (MR5) is more suitable to describe this nonlinear mechanical response of the stress-strain curves of our samples as illustrated in Figure 4a, in accordance with previous results of the archival literature. 38,39 The corresponding fitting parameters are listed in Table 3 and we observe that the correlation coefficient is found typically equal to 0.999.…”

Section: Analysis Using Phenomenological Modelssupporting

confidence: 87%

“…The samples swollen with this manner are then axially stretched until moderated deformations typically (40%). As reported by us elsewhere, 29,30 a significant reduction of the mechanical properties was observed owing to the decrease of the effective crosslinks density υ cross . For both dry and swollen samples, the υ cross can be determined by T A B L E 1 A summary of the parameters of the phenomenological and micromechanical models used in our analysis.…”

Section: Methodssupporting

confidence: 68%

“…PP E ND IX B: KINETICS OF SOLVENT SORPTION/DESORPTION IN EBA/CB COMPOSITE SAMPLES UNDER FREE-SWELLING CONDITIONS IN TOLUENETo compare the sorption/desorption kinetics in the CB-EBA composites, both time variations of the percentage of toluene sorption Q t,sorption and desorption Q t,desorption are measured at room temperature according to the experimental protocol detailed elsewhere 29,30. Then, Q t,sorption and Q t,desorption (mol%) are calculated from…”

mentioning

confidence: 99%

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Assessing robustness of hyperelastic models for describing nonlinearity of the mechanical response for pristine and swollen carbon black filled elastomers

Boulman,

Mdarhri,

Nezili

et al. 2024

Self Cite

We consider the hyperelastic response of semi‐crystalline ethylene–co‐butyl acrylate (EBA) samples filled with carbon black (CB) particles. Such material is structurally complex with its microstructure being characterized by many structural parameters including crosslink density, filler/matrix interfaces, crystallinity, filler network, and chain entanglement which have different degrees of influence on the effective mechanical properties. We evaluate the ability of a number of analytical models to correctly reproduce the non‐linear elastic mechanical response of these samples. We do this by considering either dry samples, or samples which are swollen by a non‐polar solvent (toluene) at equilibrium, and subjected to uniaxial tension at room temperature. As test cases, we focus on six physical models for the purpose of analyzing the stress–strain curves of samples with different cross‐linking densities. Among these frameworks, we show that the Mooney–Rivlin (MR), Ogden, and eight‐chain models accurately describe the stress–strain curves of both dry and swollen CB‐EBA samples. These findings highlight the possibility of attaining a diverse set of mechanical properties of filled polymer samples by tailoring their structural parameters.

Mechanical and physical properties of flexible polyurethane foam filled with waste tire material recycles

Nezili,

El Aboudi,

et al. 2024

In this work we use ground tire rubber (GTR) powder obtained by grinding worn tire treads as reinforcer agent in flexible polyurethane (PU). Characterization of the microstructure of the as‐received powder is achieved using a series of standard techniques including scanning electron microscopy (SEM), granulometry‐laser, Fourier transform infrared spectroscopy (FTIR), and x‐ray diffraction (XRD). To have complementary physical information the composition and thermal characteristics of the GTR powder, thermogravimetry analysis (TGA) is also performed. The set of these preliminary characterizations shows that the GTR powder particles can be used as reinforcing fillers. For the purpose of good compatibility with the PU matrix, the GTR powder is subjected to chemical treatments for reducing the impurities on the powder particles and to create functional groups at their surface. Subsequently, a series of GTR/PU composite samples are prepared with different weight fractions of GTR using free rising foam method. The GTR/PU composites are then characterized to assess the effect of the GTR content and their chemically pre‐treatment on thermal stability, compression mechanical behavior as well as sound attenuation properties. Collectively, these results indicate a significant improvement of both thermal and mechanical properties of the GTR/PU composites compared to the pristine PU matrix. Furthermore, it is also emphasized that the sound absorption response shows a significant shift of the maximum of the absorption coefficient toward lower frequencies resulting from simultaneous increase in air‐flow resistivity and tortuosity which can have great potential application in the field of underwater acoustics. The effects of chemical treatments and GTR amount are also discussed. It is also shown that the results show improvement when H2O2 solvent is used in comparison with NaOH, and the optimal properties are reached for PU samples containing 20 wt% of GTR whatever the pre‐treatment is.