Solid freeform fabrication of soybean oil-based composites reinforced with clay and fibers

Soybean oil/epoxy-based composites were prepared by an extrusion freeform fabrication method. These composites were reinforced with a combination of organically modified clay and fibers. The intercalated behavior of the epoxy resin in the presence of organo-modified clay was investigated by X-ray diffraction and transmission electron microscopy. The mixture of epoxidized soybean oil and EPON(R) 828 resin was modified with a gelling agent to solidify the materials until curing occurred. The flexural modulus reached 4.86 GPa with glass fiber reinforcement at 50.6 wt% loading. It was shown that the fiber orientation followed the direction of motion of the writing head that deposited the resins and had an influence on the properties of the composite. The composites cured by curing agent Jeffamine EDR-148 were found to have lower mechanical properties than those cured with triethylenetetramine, diethylenetriamine, and polyethylenimine. In addition, the effects of clay loading and fiber loading on mechanical properties of the composites were studied and reported.