The Effects of Various Chemical Treatments of Flax (Linum usitatissimum) Fiber on Mechanical Properties of Their Biocomposites

Measurement of mechanical properties of biocomposites is a good method for evaluating their effectiveness of adhesion between fiber and polymer matrix. In this research, the effects of four different chemical treatments of flax fiber on some mechanical properties of their biocomposites was investigated. Initially, the flax fiber was soaked in alkaline, silane, benzoyle and peroxide solution and the fiber were dried in an air-cabinet drier at 70°C. After grinding, each group were separately mixed with HDPE powder at a ratio of 10% flax fiber and 90% HDPE. From these mixture, composite plates were prepared through extruding, pelleting, and rotational molding. The resulting composites were tested for their various mechanical properties using tensile tests. The test results indicated the maximum strain was 6.22%, maximum supported load at yield point was 582 N, maximum stress at yield pint was 20.26 MPa and maximum modulus of elasticity was 467.75 MPa all for alkaline treatment. It was found that all tested mechanical properties for HDPE were significantly lower than the composites made from fiber containing biocomposites. However there was no significant difference between the mechanical strength of composites produced from various chemical treatments.