Effect of wood particulate filler content on durability of composite materials

Introduction. Usage of the biocomposites is a vital component of the environment protection policy. According to the classification of the petrochemical polymers, biopolymers can be divided into thermal and plastic heat-strengthening ones. The former can be modified for reheating, and the latter cannot - due to the calcium carbonate solidification. Thermal bioplastics are developed mainly for the packaging industry, and they can be used as a binder in the biocomposite materials. Materials and Methods. Sawdust wood fibers are selected as an additive to produce reinforced rubber plastics (polyester fiber) for this study. The work objective is to determine the optimum ratio of the sawdust volume and size. In the course of the experiments, various sawdust mixtures are tested through varying the combination of their size, volume and applied loads. Research Results. The obtained results show a growth of the composite material deformation when increasing the proportion of sawdust of any volumes studied under the pressure testing, as well as a decrease in strength and tensile strain when increasing the proportion of sawdust of medium and low volumes. The strength and elongation of the composite grows with increasing the sawdust fraction volume for more than 120 mm3. Stresses increase when the size of wood sawdust is 20 mm3 and mixing ratio is 25%, therewith the material elasticity decreases. Discussion and Conclusions. In bending tests, the reduction in strength and increase in tension strain when mixing a sample with sawdust of 5 mm3, gain in strength and elongation at increasing their volume up to 25 mm3, and then the reduction of strength and tension strain at increasing their volume to 120 mm3 are observed.