Effect of polar interactions on the structure and rheology of EVA/Montmorillonite nanocomposites

Abstract

In this study we utilized X-ray diffraction, transmission electron microscopy (TEM) and various types of simple shear flow experiments to investigate the effect of the polarpolar interaction between ethylene-vinyl acetate co-polymers (EVA) and organo-silicates on the nanoscale structures and rheological properties of their melt blends.The WAXS intensities and TEM micrographs demonstrate that the exfoliation and the intercalation of nanoclays respectively prevail in EVA/Cloisite 30B nanocomposites and EVA/Cloisite 15A nanocomposites, respectively. The master curves obtained from transient shear flow tests and their Arrhenius plot demonstrate the formation of sidetethered structure in the melt blends of EVA/ Cloisite 30B nanoclay. Finally, by means of performing a series of large-strain relaxation tests and regression techniques, the single integral Wagner model, that is expected to appropriately describe the rheometric experiment data of melt blends, was established, and then a comparison of the calculated and measured viscosity and first normal stress is presented.

Investigation of enhancing effect of nano-montmorillonite on fire-retardant added low-density polyethylene–ethylene vinyl acetate hybrid system

“…In other words, this would reduce the compatibility of NMMT and ATH fillers in LE matrix with noticeable decrement in the tensile strength. This observation was also found to be different from previous studies of Merinska et al 16 and Su et al 17 They reported that the addition of NMMT in polymer could provide reinforcement effect to the polymer matrix by modifying the interfacial adhesion between the NMMT particles and polymer matrix. However, the tensile strengths of 80, 120 and 150 phr ATH added LE blends were observed to gradually increase with the increasing of NMMT loading levels.…”

Polypropylene/Ethylene—And Polar—Monomer-Based Copolymers/Montmorillonite Nanocomposites: Morphology, Mechanical Properties, and Oxygen Permeability

“…From the nanocomposites point of view, these two ethylene- and polar-monomer-based copolymers (EVA and EVOH) have a much higher number of polar functional groups than the typically used polyolefin-MAH-grafted copolymers, making them good candidates to produce exfoliated MMT structures. In the case of the binary EVA/MMT nanocomposites, mainly exfoliated structures with intercalated tactoids have been reported [ 25 , 26 , 27 , 28 ], whereas for the binary EVOH/MMT nancomposites, intercalated structures with small exfoliation are seen [ 29 , 30 , 31 , 32 ]. In this way, according to MMT exfoliation, better barrier properties are expected for the PP/EVA/MMT nanocomposites.…”

Structural, thermal and mechanical properties of polymer nanocomposites based on organosoluble polyimide with naphthyl pendent group and layered double hydroxide

“…4 In many cases, addition of only a small amount of nano-clay to the polymer matrix is sufficient to make noticeable improvements in mechanical properties, thermal stability, heat distortion temperature, barrier performance, and flame retardance. 5 –12 There are three main methods to prepare polymer–clay NCs, that is, solution methods, melt-processing methods, and in situ polymerization. 13 Most of the published works have focused on organically modified smectite clays, in particular montmorillonites, as fillers of polymeric composites.…”