Effects of silicon carbide nanoparticles and multi‐walled carbon nanotubes on water uptake and resultant mechanical properties degradation of polymer nanocomposites immersed in hot water

Abstract

Polymeric materials are prone to moisture attack when they are immersed in water or exposed to moisture. This paper aims to study the effects of multi‐walled carbon nanotubes (MWCNT) and silicon carbide (SiC) nanofillers on reinforcing the epoxy polymer against water uptake and resultant degradations of mechanical properties. Therefore, the neat epoxy and nanocomposite samples containing various weight percentages of nanofillers were fabricated and immersed in deionized hot water. The gravimetric measurements over various time intervals showed that adding MWCNTs and SiCs to epoxy caused the polymer water uptake to decrease by 50% and 46%, respectively, at initial stage of water absorption and by 26% and 18% at saturation. The epoxy water diffusion rate was reduced by 58.4% and 56.9% when MWCNTs or SiCs were introduced into the polymer, respectively. Moreover, the epoxy strength degradation due to water uptake was declined by 32% and 16% when MWCNTs and SiCs were added into the polymer, respectively, at saturation. Whereas, the epoxy stiffness degradation of the epoxy/MWCNTs and epoxy/SiCs nanocomposites were 27% and 19% lower than the neat epoxy, respectively. Furthermore, water uptake in the neat epoxy and nanocomposites was modeled using a finite element model. POLYM. COMPOS., 39:E883–E890, 2018. © 2017 Society of Plastics Engineers

Moisture Absorption of Carbon/Epoxy Nanocomposites

“…Recent progress in carbon nanoparticles (i.e., graphene, carbon nanotube, carbon nanofiber) makes them excellent candidates for performance improvements in polymers [21][22][23]. The addition of carbon nanoparticles in polymers often improves properties but may cause degradation in their long-term durability due to environmental damage.…”

“…The addition of carbon nanoparticles in polymers often improves properties but may cause degradation in their long-term durability due to environmental damage. Khoramishad and Alizahed [23] reported a 20-30% increase in tensile strength and a 12-23% increase in stiffness via multi-walled carbon nanotube (MWCNT) addition to epoxy. However, the mechanical properties of these MWCNT/epoxy composites decreased back to the level of neat epoxy when saturated with moisture.…”

Effects of seawater absorption and desorption on the long‐term creep performance of graphene oxide embedded glass fiber/epoxy composites

“…Epoxy being the more hygroscopic constituent, has a greater tendency to absorb water than GO. The hygroscopic stress thus developed at the GO/epoxy interface facilitates easy interfacial slippage, [ 51 ] which is further promoted by prolonged creep loading, leading to a drastic fall in the reinforcement efficiency of GO.…”

Epoxy‐based composite adhesives with improved lap shear strengths at high temperatures for steel‐steel bonded joints

“…[18] Incorporating reinforcing fillers into the adhesives or composite matrixes could improve thermal stability and adhesion properties of epoxy-based adhesives. Various nanofillers including multiwalled carbon nanotubes, [19] graphene oxide nanoplatelets, [20] and silicon carbide nanoparticles [21] have been utilized for improving mechanical properties of epoxies under elevated temperatures or hot-moist environment. Silica and alumina fillers were employed for improving lap shear strength of epoxybased adhesives through interactions between hydroxyl groups on fillers' surfaces and epoxy matrixes.…”