Preparation and characterization of jute- and flax-reinforced starch-based composite foams

Starch-based composite foams (SCFs) were successfully prepared by baking starch-based batters incorporating either jute or flax fibers inside a hot mold. The effect of moisture content on the mechanical properties of SCFs was investigated. Both the flexural strength and the flexural modulus of elasticity appeared to be markedly improved with addition of 5–10% by weight of the fibers. At a fixed fiber content of 10% by weight, both the flexural strength and the flexural modulus of elasticity were found to increase with increasing aspect ratio of the fibers. The improvement in the mechanical properties of SCFs was attributable to the strong interaction between fibers and the starch matrix, as evidenced by a series of scanning electron micrographs being taken on SCF fracture surface. Between jute- and flax-reinforced SCFs, jute fibers had a greater reinforcing effect than flax fibers did. Orientation of fibers was shown to have a strong effect on both the flexural strength and the flexural modulus of elasticity of SCFs, with the highest values being observed on specimens having fibers oriented in the longitudinal direction (fibers oriented perpendicularly to the crack propagation direction).