MECHANICAL PROPERTIES OF THE VIET NAM SISAL FIBRE REINFORCED POLYPROPYLENE COMPOSITE

Abstract

The static mechanical and dynamic mechanical properties of the treated sisal fiber reinforced polypropylene composites were improved by adding the compatiblizer PPgMA (polypropylene-grafted-maleic anghydride). The mechanical properties of the composites have been evaluated. By increasing PPgMA dosages from 2% and 3.5% by weight of PP matrix; the impact strength of the composites were significantly improved by 27% and 38%; the elongation increased by 21% and 36%; the tensile strength increased by 35% and 95%; the elastic modulus increased by 21% and 94% and the flexural modulus increased by 2% and 83% respectively. The dynamic mechanical properties (the storage modulus E’, the loss modulus E” and the loss factor tanδ) have been investigated in relation to the compatibility between the PP matrix and the treated sisal fibers. E’ and E” increased by increasing dosage of PPgMA and Tg decreased a little when increasing the contents of PPgMA. At higher temperatures, tanδ increased and at lower temperature tanδ decreased when increasing dosage of PPgMA. It is shown that PP/treated sisal fibers/PPgMA composites have shown the effects of cohesion when increasing the PPgMA. The fiber dispersion was studied by the transmission optical microscope (TOM). The morphology of the composites samples fractured by the impact strength tests have been studied using scanning electronic microscopy (SEM). The results show the improvement of the interaction forces between treated sisal fibers and PP matrix at higher levels of PPgMA.