Effect of Nanoclay on the Mechanical, Thermal, and Water Absorption Properties of an UP-toughened Epoxy Network

Abstract

Unsaturated polyester (UP) toughened epoxy nanocomposites were prepared, and their effective mechanical and thermal properties were studied. Two types of organo-modified montmorillonite (OMMT) clays were used to prepare the nanocomposites. X-ray diffraction (XRD) and Transmission electron microscope (TEM) analysis showed the formation of exfoliated silicate layers in the UP-toughened epoxy matrix. Mechanical tests revealed that nanocomposites (containing 1 wt % OMMT clay) showed an increase in tensile strength to 13.8%, flexural strength to 10% and impact strength to 4% compared with an UP-toughened epoxy blend. The effect of different heating rates on the curing behavior of UP toughened epoxy nanocomposites was investigated using nonisothermal differential scanning calorimetry. The data were interpreted using the Kissinger and Flynn-Wall-Ozawa models to find the curing reaction parameter. The water uptake behavior for nanocomposites increased with the addition of OMMTs.Scanning electron microscopy (SEM) micrographs indicated morphological changes in the impact fractured samples of UP-toughened epoxy nanocomposites. Downloaded by [New York University] at 10:15 14 June 2015 2 KEYWORDS: adhesives with nanoparticles; epoxy/epoxides; mechanical properties of adhesives, thermal analysis, cure/hardening, hydrogen bonding.Highlights:1. Toughened epoxy blends did not shown a reduction in mechanical properties.2. Two types of organo modified montmorillonite (OMMT) clays were incorporated at 0.5, 1, 2 and 3 wt % within a toughened epoxy system, and their effective mechanical, thermal and water absorption properties were systematically investigated.3. The nanoclay content was optimized at 1 wt % based on the mechanical performance of the toughened epoxy nanocomposites.

Synergistic effect of hybrid graphene and boron nitride on the cure kinetics and thermal conductivity of epoxy adhesives

“…It indicates that the presence of BN particles does not exert a significant impact on the well‐dispersed graphene particles in the matrix resin. These observed morphologies can help us to better understand the dispersion level of fillers in the matrix resin and resulted in a system with enhanced properties …”

Mechanical and physical characterizations of compatibilizer‐free recycled plastics blend composites modified with carbon nanotube and clay nanofiller

“…26 Nevertheless, the opposite finding of the increase in water uptake behavior was reported in nanoclay composite with 0.5-3.0 wt% of nanoclay in epoxy/ unsaturated polyester (UP) blends, in which the increment water uptake rate can be interpreted by the presence of hydroxyl (OH) groups on the nanoclay and higher free volume that allowed the diffusion of water molecules into the material. 27 Similar increased water absorption results by 6.18% was shown with the presence of 3 wt% montmorillonite (MMT) in polylactic acid (PLA)/kenaf fiber. 14 Till now, the specific reason is not found to explain the contradict phenomena.…”

“…It was stated that the inclusion of 1.5–3.0 wt% Cloisite 15A had decreased the water absorption of UHMWPE nanocomposites due to enhancement in the barrier properties induced by layered silicates 26 . Nevertheless, the opposite finding of the increase in water uptake behavior was reported in nanoclay composite with 0.5–3.0 wt% of nanoclay in epoxy/unsaturated polyester (UP) blends, in which the increment water uptake rate can be interpreted by the presence of hydroxyl (OH) groups on the nanoclay and higher free volume that allowed the diffusion of water molecules into the material 27 . Similar increased water absorption results by 6.18% was shown with the presence of 3 wt% montmorillonite (MMT) in polylactic acid (PLA)/kenaf fiber 14 .…”

Fabrication and evaluation of acrylated epoxidized castor oil‐toughened diglycidyl ether of bisphenol A nanocomposites

“…The tensile strength and tensile modulus of A1-A4 blends gradually decreased with the addition of 0.1, 0.2, 0.3, and 0.4 g/g AECO to the DGEBA resin, due to the addition of long fatty acid chains of AECO to the DGEBA backbone. [58,59] The flexural strength (117 MPa) and flexural modulus (3037 MPa) of the A2 system were higher than those of the DGEBA resin. [58,59] The flexural strength (117 MPa) and flexural modulus (3037 MPa) of the A2 system were higher than those of the DGEBA resin.…”

“…[56,57] While the aliphatic chains of AECO content increased in the DGEBA resin, there is a significant drop in matrix strength due to a reduction in cross-linking density. [58,59] The flexural strength (117 MPa) and flexural modulus (3037 MPa) of the A2 system were higher than those of the DGEBA resin. This is attributed to the chain length of the matrix increasing with the addition of AECO to the DGEBA resin, which provides a long flexible chain to the backbone of DGEBA resin.…”