Title
Effect of chemical treatments on the properties of HDPE composites with Luffa cylindrical fiber
Authors
JOSS LUIZ WESTRUP MARCOS MARQUES DA SILVA PAULA ALEXANDRE GONCALVES DAL-BOROBERTO BENAVIDES CESAR AUGUSTO CALDART JUNIOR CARLOS CORONETTI TIAGO ANDREI DOY TIAGO FRIZON and LUCIANO DA SILVA

Received April 5, 2013
Published Volume 48 Issue 3-4 March-April
Keywords Luffa cylindrical, vegetable fiber composite/HDPE, chemical treatments, compliance

Abstract
In this study, we examined the effect of the addition of Luffa cylindrical (LC) fiber on the properties of high-density polyethylene (HDPE) composites. The fibers were subjected to acetylation and alkylation reactions. The composites were then examined in terms of their mechanical properties, morphology and water absorption. HDPE/LC composites containing 3.75, 7.5 and 15 wt% LC were prepared in an extruder and were subsequently injected into specimens. The properties of composites with untreated fibers and those with treated fibers were determined according to their compositions. The composites were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, thermal analysis and tensile testing. The maximum improvement in mechanical properties was obtained for the composites with treated fibers. Morphological studies demonstrated that better adhesion between the fiber and the polymer matrix resulted from the alkylation treatment. The differences observed between the various composites are explained by different adhesion mechanisms. Interdiffusion takes place in untreated composites; multiple mechanisms of adsorption-wettability, interdiffusion and, to a lesser extent, chemical bonds occur in acetylated fiber composites; and finally, the adhesion in composites modified with octyl bromide is primarily due to a chemical mechanism based on covalent bonds.