Syntactic foams from copolymers based on epoxidized soybean oil

Syntactic foams are been increasingly used as core of sandwich panels due to their light weight and good mechanical properties. This investigation evaluates the compressive, flexural and thermo-mechanical properties of syntactic foams made by embedding randomly dispersed hollow glass microspheres in bio-based resins obtained by partial substitution of diglycidyl ether of bisphenol A (DGEBA) with epoxidized soybean oil (ESO). Volume fraction of glass microballoons was 0.55 in all foam formulation. Flexural and compressive strength values decreased simultaneously with increasing ESO content. Similar trend was observed for the flexural and compressive modulus and glass transition temperature. The work further showed that mechanism of failure mainly depended on the fracture of microballoons regardless the ESO content in the formulation. Results reported herein suggest that large fractions of DGEBA can be replaced by ESO with minor effect on mechanical and thermal properties.