Chemical treatment of coconut fiber and its composite / Tratamento químico da fibra de coco e seus compósitos

Abstract

Composites with natural fibers usually present poor adhesion of filler to the matrix, as consequence of the hydrophilic nature of the fiber and hydrophobic nature of the polymer. These composites also display processing limitations due to the low thermal stability of the fiber. In order to reduce these issues, chemical treatments are usually employed. Thus, the present work aims to combine the processes of mercerization and bleaching to evaluate changes in thermal stability, tensile and impact strengths, flow behaviour and morphology of composites based on HDPE/coconut fiber, with treated and untreated fibers. The results showed that the treated fiber showed better thermal stability comparing to untreated one. The composites produced with both fibers showed an increase in elastic modulus and a reduction in the flow behaviour. However, only those obtained with the treated fiber showed an increase in impact strength in relation to neat HDPE, indicating a better interaction between the treated fiber and the HDPE matrix. These results corroborate the images obtained in SEM micrographs.