The influence of chemical surface modification on the performance of sisal-polyester biocomposites

This article concerns the effectiveness of various types and degrees of surface modification of sisal fibers involving dewaxing, alkali treatment, bleaching, cyanoethylation and vinyl grafting in enhancing the mechanical properties, such as tensile, flexural and impact strength, of sisal-polyester biocomposites. The mechanical properties are optimum at a fiber loading of 30 wt%. Among all modifications, cyanoethylation and alkali treatment result in improved properties of the biocomposites. Cyanoethylated sisal-polyester composite exhibited maximum tensile strength. (84.29 MPa). The alkali treated sisal-polyester composite exhibited best flexural (153.94 MPa) and impact strength. (197.88 J/m), which are, respectively, 21.8% and 20.9% higher than the corresponding mechanical properties of the untreated sisal-polyester composite. In the case of vinyl grafting, acrylonitrile (AN)-grafted sisal-polyester composites show better mechanical properties than methylmethacrylate (MMA)-grafted sisal composites. Scanning electron microscopic studies were carried out to analyze the fiber-matrix interaction in various surface-modified sisal-polyester composites.