Natural Durability of a Bagasse Fiber/ Polypropylene Composite Exposed to Rainbow Fungus ( Coriolus versicolor)

Abstract

To evaluate the natural durability of a composite obtained from bagasse fibers and polypropylene against rainbow fungus (Coriolus versicolor), materials containing 75% bagasse fibers, 23% polypropylene, and 2% compatibilizer were sampled. After specimen and culture medium preparation the specimens were exposed to the purified fungus at 25°C and 75% relative humidity for 1, 2, 3, and 4 months. Identical specimens of the same composite, without being exposed to the fungus, were provided as the control specimens. After the mentioned periods, mass loss, bending strength, elastic modulus, hardness, water absorption, and equilibrium moisture content of specimens were measured. The obtained results indicated that mass, bending strength, elastic modulus, hardness, and equilibrium moisture content of composites decreased, whereas water absorption amount of specimens increased. The calculation of correlation coefficients between the rates of mass loss and bending strength, elastic modulus and hardness decreases, as well as equilibrium moisture percentage in composite specimens revealed that a significant correlation existed between the values. Comparing mechanical properties after exposure to fungus, it is observed that elastic modulus was affected by the fungus exposure to a greater extent, whereas hardness decrease was less than the other properties.