Investigating the effects of resin crosslinking ratio on mechanical properties of epoxy‐based nanocomposites using molecular dynamics

Abstract

Finite-element method and micromechanical formulations have been used to predict mechanical properties of epoxy-based nanocomposites in recent years. The results of these investigations, however, show large scatters and do not agree well with experimental measurements. The differences in the results may be due to the fact that these approaches do not take some important material parameters into account, such as resin crosslinking ratio, nanotube/matrix interface, and nanotube agglomeration. The main objective of this article is to investigate the effects of resin crosslinking ratio on mechanical properties of epoxy-based nanocomposites using molecular dynamics (MD). First, models of partially cured epoxy resin were created in Materials Studio software to determine resin properties at different crosslinking ratios. Next, one sample of neat epoxy and four samples of nanocomposite with different resin crosslinking ratios were modeled using MD. These models were analyzed using constant strain method to determine mechanical properties of the five samples. Also, the effects of crosslinking ratio on nanocomposite density were investigated. The simulation results show that nanocomposite Young's modulus increases with resin crosslinking ratio. Resin crosslinking ratio, however, did not have a significant effect on nanocomposite density. Further, molecular simulation results were compared with rule of mixtures and Mori-Tanaka predictions. In addition, the results were compared with those found in the literature and good agreement was observed between the results. POLYM. COMPOS., 38:E433-E442, 2017.

Modeling the interphase region in carbon nanotube‐reinforced polymer nanocomposites

“…The elastic properties of the interphase, however, are assumed to vary continuously between those of the main phases, that is, inclusion and matrix (Figs. [2][3][4][5][6]. Furthermore, inclusion is considered in cylindrical form.…”

“…For example, the transverse Young's modulus of the CNT‐reinforced epoxy‐based nanocomposites was found to be increased with the enhancement of resin's cross‐linking ratio. In addition, the CNT diameter was observed to have a strong influence on nanocomposite longitudinal and transverse moduli .…”

Investigating the effects of CNT aspect ratio and agglomeration on elastic constants of crosslinked polymer nanocomposite using multiscale modeling

“…Note in this table that the effective fibers have transversely isotropic properties for all cases, as expected. In the above calculations, the matrix Young's modulus, E m , is assumed 2.8 GPa which is determined using molecular dynamics simulations .…”

“…Due to the nano effect in nanostructured materials, nanocomposite mechanical properties are very sensitive to filler size . Nanocomposite mechanical properties are affected by different factors such as reinforcement size, distribution, orientation, and morphology . In CNT‐reinforced composites chirality and aspect ratio have great influences on elastic properties.…”

Thermoelastic analysis of functionally graded cylinders reinforced by wavy CNT using a mesh‐free method

“…Recently, the excellent specific strength, specific stiffness, thermal, electrical, and chemical properties of carbon nanotube (CNT) cause to use it as significant reinforcement materials for high performance structural composites with much application potential . Most studies on nanocomposite reinforced by CNT have focused on their material properties and some investigations have shown that the addition of small amount of CNT in the matrix can considerably improve the mechanical, electrical and thermal properties of polymeric composites . Martone et al studied on the effects of CNT aspect ratio (AR) and waviness on the reinforcement behavior of CNT/epoxy composite.…”