EVA/clay nanocomposite by solution blending: Effect of aluminosilicate layers on mechanical and thermal properties

Abstract

Ethylene vinyl acetate (EVA)/clay nanocomposites were synthesized by blending a solution of ethylene vinyl acetate copolymer containing 12% vinyl acetate abbreviated as EVA-12 in toluene and dispersion of dodecyl ammonium ion intercalated montmorillonite (12Me-MMT) in N,N-dimethyl acetamide (DMAc). X-ray patterns of sodium montmorillonite (Na + -MMT) and 12Me-MMT exhibited d 001 peak at 2θ = 7.4 o and 2θ = 5.6 o respectively; that is, the interlayer spacing of MMT increased by about 0.39 nm due to intercalation of dodecyl ammonium ions. The XRD trace of EVA showed no peak in the angular range of 3-10 o (2θ). In the XRD patterns of EVA/clay hybrids with clay content up to 6 wt% the basal reflection peak of 12Me-MMT was absent, leading to the formation of delaminated configuration of the composites. When the 12Me-MMT content was 8 wt% in the EVA-12 matrix, the hybrid revealed a peak at about 2θ = 5.6 o , owing to the aggregation of aluminosilicate layers. Transmission electron microscopic photograph exhibited that an average size of 12-15 nm clay layers were randomly and homogeneously dispersed in the polymer matrix, which led to the formation of nanocomposite with delaminated configuration. The formation of delaminated nanocomposites was manifested through the enhancement of mechanical properties and thermal stability, e.g. tensile strength of an hybrid containing only 2 wt% 12Me-MMT was enhanced by about 36% as compared with neat EVA-12.

Exertion of Inhibiting Effect by Aluminosilicate Layers on Swelling of Solution Blended EVA/Clay Nanocomposite

“…This is because of the fact that, beyond 4-6 wt.-% of clay content, aluminosilicate layers probably start to aggregate in the EVA matrix as observed in our earlier works on EVA. [17][18][19][20] An exclusive TEM photograph of EVA/12Me-MMT nanocomposite containing 2 wt.-% filler was produced with the help of high resolution microscope (CM 12, Philips) with an acceleration voltage of 120 kV, where it is observed that the aluminosilicate layers are dispersed homogeneously and randomly on nano-level in EVA matrix shown in Figure 4(a). Additionally, another one TEM photograph of EVA/12Me-MMT nanocomposite with 8 wt.-% 12Me-MMT is displayed in Figure 4(b), where the aggregated aluminosilicate layers marked by dark densed portion are noticed very distinctly.…”

“…[17][18][19][20] Square or rectangular shape of these nanocomposites were cut and weighed. The weighed (W i ) samples were immersed in xylene and allowed to swell at room temperature (28.5 8C).…”

“…In our previous work on EVA/clay nanocomposites we reported that the EVA matrix was thermally and mechanically reinforced when dodecyl ammonium ion intercalated montmorillonite is dispersed on nanometer scale. [17][18][19][20] EVA/organoclay nanocomposites were also synthesized via melt intercalation method by Li et al [21] , Zanetti et al [22] and Alexandre et al [23] Li et al [21] showed that the dispersion of organoclays in the EVA matrix depends on the hydrophobicity of the organoclays and especially the polar interactions between the silicate layers and EVA chains. Zanetti et al [22] developed EVA/octadecyl ammonium ion intercalated fluorohectorite nanocomposites and investigated their thermal stability.…”

Mechanical and Thermal Properties of Clay-poly(norbornene) Nanocomposites from Ruthenium Alkylidene-mediated Surface-initiated Polymerization

“…( Alexandre & Dubois, 2000;Awad et al, 2009;Braganca et al, 2007;Kawasumi et al, 1997;Kaynak et al, 2009;Maiti et al, 2002;Pramanik et al, 2003;Ray et al, 2003). The stable grafting of the polymer chains to the inorganic clay substrate may have also contributed to the increased tensile modulus of the clay-filled poly(norbornene) films.…”

Effects of interface affinity on the rheological properties of zinc oxide nanoparticle-suspended polymer solutions

“…1,2 When inorganic nanoparticles are incorporated in the polymer solutions, their flow properties might be changed differently from those of micronsized particle filled ones due to unusually large specific surface area. The adsorption phenomena of polymers on solid nanoparticles are known to influence strongly the microstructure of polymer/particle systems.…”