3D Fiber-Reinforced Syntactic Foams Based on Amino Microspheres

摘要

A new type of microsphere based on fire-resistant amino resin was used to fabricate composite syntactic foams. The foams were fabricated using a phenolic resin binder and were reinforced with chopped fibers (carbon fiber and aramid fiber). The aim of the study was to synthesize the foams and to assess suitability of the composite foam as a sandwich core material. Compressive, shear, and tensile strength and moduli were measured in directions parallel and perpendicular to the preferred fiber orientation. The results showed that the fibers were more effective in enhancing the strength and moduli of syntactic foams when loads were applied parallel to the dominant fiber orientation. When loaded perpendicular to the dominant fiber orientation, properties were enhanced 30 - 40% compared with the unreinforced (neat) foam, but when load was applied parallel to the dominant fiber orientation, the compressive strength of the composite foam increased by a factor of up to 2; the tensile strength and modulus increased by a factor of up to 7 and 8, respectively, and the shear strength and modulus increased by a factor of up to 3.3 and 2.3, respectively. The properties of the composite syntactic foams fabricated in the present study generally surpassed those of commercial PVC foams of comparable density (300 kg / m3). The shear strength of the composite syntactic foams was comparable to balsa wood of comparable density and to some types of honeycomb.