Preparation and characterization of three phase epoxy syntactic foam filled with carbon fiber reinforced hollow epoxy macrospheres and hollow glass microspheres

Abstract

The present study focuses on the preparation and characterization of three phase epoxy syntactic foam (ESF) filled with carbon fiber reinforced hollow epoxy macrospheres (CFR-HEMS) and hollow glass microspheres (HGMS). The ESF was produced by embedding CFR-HEMS into a mixture of epoxy-hardener and 30 wt% HGMS. An innovative approach and simple procedure was implemented in the preparation of CFR-HEMS where expanded polystyrene (EPS) beads were used as initiation template. The EPS beads were coated with epoxy resin and carbon fiber using "rolling ball method," and these coated EPS beads were later cured and postcured at high temperature which will shrink the EPS beads thus producing a hollow macrosphere structure. The compressive property of ESF was characterized and the mechanical model was issued. The ESF (450 kg/ m 3

Comparison of two different methods for producing hollow macrospheres with carbon fiber reinforced composite skin used in syntactic foams

“…Compressive failure mechanisms of the three‐ phase ESF is explained as follow: crack initially occurred in the matrix and then caused the formation of a shear crack in the longitudinal direction with the further compression. The longitudinal crack grew and the crushing of the HEMs was initiated and resulted in more filling up of the matrix porosity due to the rupture of the porous feature . The damage process of ESF‐II is similar to ESF‐I.…”

“…In order to increase the mechanical properties, it is necessary to form a composite shell over the core of polymer fillers. According to published literatures, “rolling ball” method is the most popular way to prepare fiber reinforced hollow epoxy macrospheres (HEMs) with EPS beads . The EPS beads were directly blended with the mixture of resin and short fibers in a “rolling ball” machine.…”

Effect of crumb rubber on mechanical properties of multi-phase syntactic foams

“…The syntactic material can find applications owing to its characteristics of thermal efficiency, lightweight and high compressive strength and toughness [23,24]. The syntactic foam material has been intensively employed for marine applications including deep-water exploration, which needs to withstand enormous water pressure while provide sufficient buoyancy [3,25]. Sandwich structure made of two thin stiff face-sheets and various thick cores is used to absorb energy and resist loads.…”

“…The binder matrix can be made of polymeric resin, metal and ceramic [1] and the fillers are in forms of microsphere and macro-sphere, which are made from rigid materials such as glass, carbon, metal, ceramic, cenosphere and polymeric materials [2]. The syntactic foams are commonly categorized as 2-phase and 3-phase [3]. It is noted that this classification is based on the main compositions of the material regardless the additive (e.g.…”

“…The macro-sphere, as reinforcing filler of syntactic foam, can be made of spheres coated with fibre reinforced epoxy. For instance, Wu et al [3] developed a macro-sphere by coating Expanded Polystyrene (EPS) beads with carbon fibre reinforced epoxy using rolling ball method.…”