Abstract:
This thesis studied the reinforced polyethylene composites from sisal fiber and the effect of fiber content and silane content. The appropriated proportion of polyethylene composites and sisal fiber could be use in rotational molding process manufacturing. The result of rotational molding process by varying temperatures shows that the appropriated forming temperature and time are 230 celcius degrees and 12 minutes that could be affected to mechanical properties and physical properties. While, the composite specimens were prepared by rotational molding process with the various contents of sisal fibers. Both untreated sisal fiber and silane treated fibers were studied. The fabricated results showed that the polyethylene composites reinforced by short sisal fibers can be prepared by rotational molding with untreated sisal fiber contents of 10 40 w.t.% and can be increased the treated fibers with Vinyl Triethoxy Silane 10 50 w.t.%. Silane can be improved interfacial interaction between polymer and filler that form bonding interaction together. Molecular can be divided 2 parts. Part 1 reacts with filler and the other reacts with polymer that become Covalent between filler and polymer. So, sisal fiber has good interfacial interaction. The results of mechanical properties showed that the polyethylene composites reinforced by short sisal fibers are increase the tensile strength and Youngs modulus but decrease the elongation at break and the impact strength when comparing with pure polyethylene. In addition, the silane treated process could remove impurities and improved the interfacial bond strength between the fibers and polyethylene matrix, which would improve physical properties of the polyethylene composites. The optimum content of the treated sisal fiber was 10, 20 and 50 w.t.%, which yielded the suitable mechanical properties. At 20 w.t.% yielded tensile strength was 44.35 MPa. At 50 w.t.% yielded Youngs modulus was 590.28 MPa. At 10 w.t.% yielded the elongation at break was 180.97% and the impact strength was 13.97 kJ/m2.