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

Abstract

This article describes the influence of a hexamethyldisilane-treated nanosilica (end-capped SiO 2 ) on morphological and tensile properties of linear low-density polyethylene (LLDPE)/ethylene vinyl acetate copolymer (EVA) blends prepared by one step melt mixing process via a twin screw extruder. The treatment replaces many of the surface hydroxyl groups on the nanosilica with extremely hydrophobic trimethylsilyl groups. Transmission electron microscopic results revealed that the treated nanosilica formed small aggregates in polymer matrix and they were mostly localized in the LLDPE matrix besides localizing in EVA droplets and at LLDPE/EVA interface. These nanoparticles had compatibilizing role on the blend system and at high content changed morphology from biphasic toward a monophasic. Addition of the end-capped nanosilica to the blend and increasing its content increased the Young's modulus, tensile strength as well as elongation at break of the nanocomposites. Different models were used to predict the Young's modulus of the nanocomposites. It was found that the experimental data were better fitted by Counto model than the other models. Melt rheological investigations on the nanosilica filled LLDPE/EVA blend system showed that incorporation of the treated nanosilica, even up to 10 wt %, did not lead to a solid-like behavior at low-frequency indicating ease of processing of such highly filled system.

Dynamic mechanical analysis and thermal properties of LLDPE/EVA/modified silica nanocomposites

“…One other probable reason for this behavior is the observed changes in the blend morphology. [15] In the case of nanocomposite containing 3 wt.% nanosilica, some of nanoparticles are localized within the EVA droplets. At low temperatures, such EVA droplets are at their glassy state, and thus, the stress transfer to the nanoparticles enclosed within these droplets would be possible.…”

“…They showed that the treated nanosilica formed small aggregates in polymer matrix and they were mostly localized in the LLDPE matrix besides localizing in EVA droplets and at LLDPE/EVA interface. Moreover, these nanoparticles had compatibilizing role on the blend system and at high content changed morphology from biphasic toward a monophasic [15]. In this work, the influence of hexamethyldisilane-treated nanosilica (end-capped SiO 2 ) on microstructure and dynamic mechanical properties of LLDPE/EVA system will be investigated.…”

Nanoindentation study on mechanical properties and curing depth of dental resin nanocomposites

“…Additionally, Counto developed an effective model for a two‐phase particulate composite by assuming perfect bonding between the matrix and the filler. This model predicts moduli in good agreement with a wide range of test data . The elastic modulus is computed as …”

Cellulose triacetate/LUDOX‐SiO2 nanocomposite for synthesis of pervaporation desalination membranes

“…Besides, SiO 2 nanoparticles play a role as physical transfusion coupling between polymer parts, which reduces cracks or cavities at the membrane weak points. 48 above 15 wt% in polysulfone (PSF) membranes, the tensile strength decreased due to the accumulation of SiO 2 particles in PSF membrane. 47 These results imply that the presence of SiO 2 as inorganic nanoparticles strengthens the nanocomposite membrane due to the good dispersion of SiO 2 nanoparticles and the solid interaction between SiO 2 nanoparticles with the CTA matrix.…”