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The Impact of Ultra-Low Amounts of Amino-Modified MMT on Dynamics and Properties of Densely Cross-Linked Cyanate Ester Resins

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The Impact of Ultra-Low Amounts of Amino-Modified MMT on Dynamics and Properties of Densely Cross-Linked Cyanate Ester Resins

Vladimir Bershtein et al. Nanoscale Res Lett.

Abstract

Abstract: Thermostable nanocomposites based on densely cross-linked cyanate ester resins (CER), derived from bisphenol E and doped by 0.01 to 5 wt. % amino-functionalized 2D montmorillonite (MMT) nanoparticles, were synthesized and characterized using Fourier transform infrared (FTIR), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDXS), wide-angle X-ray diffraction (WAXD), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), far-infrared (Far-IR), and creep rate spectroscopy (CRS) techniques. It was revealed that ultra-low additives, e.g., 0.025 to 0.1 wt. %, of amino-MMT nanolayers covalently embedded into СER network exerted an anomalously large impact on its dynamics and properties resulting, in particular, in some suppression of dynamics, increasing the onset of glass transition temperature by 30° to 40° and twofold rise of modulus in temperature range from 20°C to 200°C. Contrarily, the effects became negligibly small or even negative at increased amino-MMT contents, especially at 2 and 5 wt. %. That could be explained by TEM/EDXS data displaying predominance of individual amino-MMT nanolayers and their thin (2 to 3 nanolayers) stacks over more thick tactoids (5 to 10 nanolayers) and the large amino-MMT aggregates (100 to 500 nm in thickness) reversing the composite structure produced with increasing of amino-MMT content within CER matrix. The revealed effect of ultra-low amino-MMT content testifies in favor of the idea about the extraordinarily enhanced long-range action of the 'constrained dynamics' effect in the case of densely cross-linked polymer networks.

Pacs: 82.35.Np Nanoparticles in polymers; 81.05.Qk Reinforced polymers and polymer-based composites; 81.07.Pr Organic-inorganic hybrid nanostructures.

Keywords: Cyanate ester resins; Dynamics; Montmorillonite; Nanocomposites; Properties.

Figures

Figure 1
Figure 1
FTIR spectra of neat CER matrix, amino-MMT, and CER/amino-MMT nanocomposites. The spectra are shifted vertically for the sake of clarity.
Figure 2
Figure 2
Schemes of synthesis and chemical structure of CER/amino-MMT nanocomposites. Polycyclotrimerization of cyanate ester resin (a), chemical interaction between cyanate groups of CER and amino groups of amino-MMT (b), and the idealized structure of the hybrid CER/amino-MMT nanocomposites (c).
Figure 3
Figure 3
TEM micrographs obtained for CER/amino-MMT nanocomposites. 5 (a), 2 (b), 1 (c, d), and 0.1 (e, f) wt. % nanoparticles.
Figure 4
Figure 4
WAXD patterns of CER/amino-MMT (95/5) mechanical mixture (1) and the nanocomposite (2).
Figure 5
Figure 5
Typical TEM micrograph and the EDX spectra for CER/amino-MMT (99.9/0.1) nanocomposite. The EDX spectra, taken from 2-nm spots in diameter at this nanolayer (1) and within the surrounding matrix (2), are also shown.
Figure 6
Figure 6
Far-IR spectra of neat CER matrix and the CER/amino-MMT nanocomposites. Numbers indicate amino-MMT contents. (a) Changing of the spectrum due to introducing 0.05 wt. % amino-MMT; (b) the absorption band of ring vibrations (librations), and (c) the absorption band of skeletal torsional vibrations which is practically identical for neat matrix and the nanocomposites with 0.05, 0.5, and 1 wt. % MMT.
Figure 7
Figure 7
DMA: temperature dependencies of tan δ for the neat CER matrix and the CER/amino-MMT nanocomposites. Inset: T g values taken as the temperatures of these peaks’ maxima versus amino-MMT content plot.
Figure 8
Figure 8
Glass transition temperatures of the CER/amino-MMT nanocomposites as estimated by DSC and DMA. Black squares indicate glass transition temperatures for the neat CER matrix.
Figure 9
Figure 9
DMA: storage modulus E ′ as a function of amino-MMT content in the CER/amino-MMT nanocomposites. Black squares indicate E′ values for the neat CER matrix.
Figure 10
Figure 10
Creep rate spectra for the neat CER matrix and the CER/amino-MMT nanocomposites. Tensile stress σ applied: 0.5 MPa (a) and 0.05 MPa (b).
Figure 11
Figure 11
TGA curves for the CER/amino-MMT nanocomposites. Numbers indicate nanofiller contents.

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References

    1. Gupta RK, Kennel E, Kim K-J (eds). Polymer Nanocomposites: Handbook. New York: CRC Press, Taylor & Francis Group; 2009.
    1. Reddy BP (ed). Advances in diverse industrial applications of nanocomposites. InTech; 2011.
    1. Nicolais L, Borzacchiello A, Lee SM (ed). Wiley Encyclopedia of Composites. Wiley; 2012
    1. Papaspyrides CD, Kiliaris P (eds). Polymer green flame retardants. Elsevier; 2014.
    1. Bergaya F, Lagaly G (eds). Handbook of clay science. In Developments in Clay Science, vol.5, 2nd ed. Elsevier; 2013.
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