Properties Of Epoxy-based Nanocomposites Research Articles

Sound Velocities in Graphene-Based Epoxy Nanocomposites

Elastic properties of epoxy-based nanocomposites (ENCs) filled with bare and TiO2-deposied multi-layered graphene nanoplatelets (MLG) have been tested by using a phase-frequency continuous-wave ultrasound probing (USP). The dian epoxy CHS-EPOXY 520 curried with diethylenetriamine (DETA) was the polymer matrix for the nanocomposites. The nanoplatelets of the specific surface area Sf ~ 790 m2/g consist of several dozen loosely bound monoatomic graphene layers with an area of about least 5×5 μm2. MLG-mass-loading (φf,m) of the nanocomposites varied from 0.1 % to 5.0 % by weight. Anatase- TiO2 particles, being of about 50 nm in diameter and of Sf ~ 1500 m2/g, have been deposited on MLG in mass concentration of about 1 %. Elastic moduli of the ENCs (namely, the Lame’s constants, the Young’s module, the compression module, and the Poisson’s ratio) have demonstrated negligible variation with φf,m varying regardless the type of filling particles. However, MLG:TiO2-hybrid nanoparticles have proven to impact stronger on the moduli as compared to bare MLG. This result shows a capability to modify molecular structure of epoxy resins by controlling surface reactivity of MLG embedded in the resin.

Effect of surfactant treatment on thermal stability and mechanical properties of CNT/polybenzoxazine nanocomposites

Abstract The mechanical and thermo-mechanical properties of polybenzoxazine nanocomposites containing multi-walled carbon nanotubes (MWCNTs) functionalized with surfactant are studied. The results are specifically compared with the corresponding properties of epoxy-based nanocomposites. The CNTs bring about significant improvements in flexural strength, flexural modulus, storage modulus and glass transition temperature, Tg, of CNT/polybenzoxazine nanocomposites at the expense of impact fracture toughness. The surfactant treatment has a beneficial effect on the improvement of these properties, except the impact toughness, through enhanced CNT dispersion and interfacial interaction. The former four properties are in general higher for the CNT/polybenzoxazine nanocomposites than the epoxy counterparts, and vice versa for the impact toughness. The addition of CNTs has an ameliorating effect of lowering the coefficient of thermal expansion (CTE) of polybenzoxazine nanocomposites in both the regions below and above Tg, whereas the reverse is true for the epoxy nanocomposites. This observation has a particular implication of exploiting the CNT/polybenzoxazine nanocomposites in applications requiring low shrinkage and accurate dimensional control.

The Effect of WS2 Nanotubes on the Properties of Epoxy-Based Nanocomposites

In this paper we evaluated the effect of embedding inorganic nanotubes (INT) of tungsten disulfide (WS2) in an epoxy matrix, on the mechanical, thermal and adhesion properties of the resulting nanocomposites. The nanotube content spanned a range of values (0, 0.1, 0.3, 0.5 and 1.0 wt%), and the nanotube incorporation process consisted of a combination of both distributive (magnetic stirring) and dispersive (ultrasonic mixing) methods. The adhesion of the nanocomposites to an aluminum substrate was characterized by both a single lap shear and a T-peel test. The fracture toughness (K IC) of the nanocomposites was characterized by a standard compact tension (CT) plane-strain fracture test. The thermal properties of the nanocomposites were determined by dynamic mechanical thermal analysis (DMTA). Overall, the addition of INT-WS2 was found to improve the shear strength and peel properties of the nanocomposite, and to significantly improve its fracture toughness and glass transition temperature. The extent and character of the nanotube–epoxy interaction were examined by electron microscopy, as was the energy dissipation mechanisms during fracture.