Natural Hybrid Reinforcement Effect on Mechanical Properties of UPE Composite

In this paper the effect of adding natural particles (pomegranate PSP and coconut shell particles CSP ) on unsaturated polyester matrix UPE reinforced with natural sisal fibers studied, some mechanical properties were performed. The natural particle percentage selected to be (5, 10, 15, 20) wt. %, while the percentage of the sisal fibers was constant (2wt. %). The main purpose was to improve UPE properties to be use in structural applications. Chemical treatment was perform on all the reinforcement materials used before the hybrid composite synthesis. Using particles size distribution (PSD) it was found that (2956.9 and 2961.6) nm were the size of PSP and CSP, respectively. Then, samples were prepared in the laboratory at room temperature using Hand-layup technique. Tests as Flexural strength, flexural modulus, impact strength, max shear strength and surface roughness were applied on the composite samples. Results were as follows: a clear improvement in the mechanical properties of the UPE reinforced with sisal fibers. As for the fiber-particle reinforced polyester (UPE) ,the results were an increase in the flexural modulus by 5wt.% when adding coconut particle, while it decreased when adding pomegranate particle at same ratio. As for the flexural strength when the adding particles ratio increases, it decreases in the case of pomegranate particles addition while increases in the coconut particles addition. Interestingly, impact strength value increased at 5wt.% for both particle addition, while for further ratio there was a value reduction. An increase in max shear strength was also found as the highest value was in the pomegranate matrix at 5wt.%, while it was in the coconut matrix at 20wt.%. Finally, that the surface roughness value gradually increases with the increase additive ratio. Also, SEM