Effect of particle morphology on viscoelastic and flexural properties of epoxy–alumina polymer nanocomposites

Abstract

Nanocomposites were synthesised by dispersing two different types of alumina nanoparticles in epoxy matrix by ultrasonication. Alumina nanoparticles of two shapes, rod and spherical were selected to investigate the effect of particle morphology on viscoelastic and flexural properties of nanocomposites. Specific surface area of both the selected nanoparticles was kept in the similar range. Good dispersion of nanoparticles was observed through transmission electron microscopy. The addition of nanoparticles in epoxy had significant enhancement in the viscoelastic properties and moderate improvement in flexural properties of composites. Composites having alumina nanorods showed higher improvement both in storage modulus as well as in flexural properties in comparison to composites having spherical alumina nanoparticles. Efficacy of Mori-Tanaka method was explored in modelling storage modulus of nanocomposites. Assorted size of alumina nanorods based on particle size distribution was used to model composites with nanorods to see the effect of size assortment on storage modulus.

Nanoparticle Loading of Unentangled Polymers Induces Entanglement-Like Relaxation Modes and a Broad Sol–Gel Transition

“…The loading of nanoparticles (NPs) into polymeric matrices generally yields a mechanical reinforcement of the polymer nanocomposites (PNCs) relative to the neat polymer host, even at low NP loadings. − The growing availability of NPs with controllable affinities and the development of instrumentation to probe small length scales have spurred renewed studies in mechanical reinforcement as well as viscoelasticity of PNCs. − A detailed study of the mutual interplay between NPs and host polymer chains, linking structural properties, modified relaxation dynamics of polymer chains and NPs, and dynamic mechanical and rheological properties of PNCs, is imperative for quantitative and predictive engineering of function-specific PNCs. − …”

Strain rate dependency on failure load and stress intensity factor of single lap steel joints bonded with epoxy adhesive reinforced with nano‐Al2O3 sphere and rod particles

“…Due to the formation of agglomerates, the nano‐Al 2 O 3 did not create a chemical bond appropriately with epoxy in the matrix. Hiremath and Shukla 31 observed that at high wt% of nano‐Al 2 O 3 , the viscosity of nanocomposites increases because a non‐uniform dispersion of nano‐Al 2 O 3 takes place in the matrix. At higher wt% of nano‐Al 2 O 3 , the distance among the nanoparticles reduced in 0.1 mm thickness of the adhesive layer.…”

“…Spherical‐shaped nano‐Al 2 O 3 (nanospheres) was provided by Nanostructured and Amorphous Materials, Inc. Sigma‐Aldrich Corporation, India provided rod‐shaped nano‐Al 2 O 3 (nanorods). The properties of the adherend, adhesive 31 and nano‐Al 2 O 3 31 are mentioned in Table 1.…”

Thermal stability of gamma irradiated ethylene propylene diene monomer composites for shielding applications

“…Load transfer between particles and EPDM matrices contribute toward the flexural strength of the composites. 44 Flexural properties found to increase upon irradiation comparing to unirradiated samples. The flexural properties found to be related to the crosslinking of the EPDM composites.…”

“…Flexural modulus is a measure of a materials stiffness or resistance to bending action, the sampling configuration is known as the threepoint bend test. 44 The flexural properties are measured by using Dynamic Mechanical Analyzer up on a constant frequency and temperature in rubbery region at 25 C. Figure 5 shows the effect of irradiation doses on the flexural characteristics for four EPDM blends with different wt% of fillers (W, BaSO 4 ). Load transfer between particles and EPDM matrices contribute toward the flexural strength of the composites.…”