Effect of silica‐based nanofillers on the properties of a low‐density polyethylene/ethylene vinyl acetate copolymer based thermoplastic elastomer

Abstract

The effect of pristine silica nanoparticles on a model low-density polyethylene (LDPE)-ethylene vinyl acetate copolymer (EVA) thermoplastic elastomer blend system is explored in this article. Pristine silica nanoparticles were melt-blended with the LDPE-EVA system at 1.5, 3, and 5 wt % loadings through the variation of the sequence of addition. In one of the compositions, coupling agent bis [3-(triethoxysilyl)propyl] tetrasulfide (Si-69) was used to improve the interaction of hydrophilic silica fillers with the polymer matrix. The blends were compressionmolded, and their mechanical, dynamic mechanical, and thermal properties, X-ray diffraction patterns, and morphology were evaluated. The properties of the blends were found to be strong functions of the sequence of addition of nanofillers during their preparation. With Si-69 as a coupling agent, the dynamic storage modulus of nanosilica-based composites was found to increase up to 35%. An appreciable improvement in the tension set properties of the thermoplastic elastomer nanocomposites was observed in all the nanosilica-based films. Morphological studies and dynamic properties clearly indicated that the differential properties of these blend systems primarily stemmed from the extent of dispersion and alternation of crystalline morphology, which in turn was a strong function of preferential incorporation in the LDPE or EVA matrix and the agglomeration tendency of the nanofillers.

Effect of controlled electron beam irradiation on the rheological properties of nanosilica‐filled LDPE‐EVA based thermoplastic elastomer

“…15 In all the compositions, EVA domains have been found to exist as dispersed phase in the continuous matrix. 17 However, it has been found that in CS/3-1, in the continuous phase, due to intermixing of EVA and LDPE silica particles remained associated in both phases as well as in the interface. This intermixing phenomenon has been proven by extensive FTIR and TEM analysis in one of our recent publications.…”

“…15 Because of intermixing, crystallinity of LDPE matrix was reduced. 17 On the contrary, for CS/3-2 no such intermixing was found as the silica-EVA masterbatch was prepared previously before mixing them with LDPE. Here, silica particles were mostly found to be associated with the EVA domains.…”

“…It again invokes the possibility of better interfacial bonding which outweigh the effect of changes in crystallinity in this case than that of other samples. 17 In CS/3-2/2R, interfacial bonding is inferior such that strain retention capacity at moderate range of elongation is less. The stress ratio for all samples begins to fall at higher strains when compared with that of unirradiated samples.…”

Polyblend Nanocomposites

“…The mechanical and dielectric properties of PVDF/ MWCNTs nanocomposites were improved with PU addition (77). The addition of a silane coupling agent to nano silicafilled LDPE/EVA thermoplastic elastomer polymer blends leads to significant increases in the tensile strength, Young's modulus, extensibility and dynamic properties (78).…”

Effect of end‐capped nanosilica on mechanical properties and microstructure of LLLDPE/EVA blends

“…1 Linear low-density polyethylene (LLDPE)/ethylene vinyl acetate copolymer (EVA) blends are used extensively in many applications such as wire and cable coating industry as insulation or jacket, shrinkable films, and multilayer packaging. The polymer blending is one of the economical and easy routes for developing new materials with novel properties.…”