Investigating the influence of mercerization treatment of sisal fiber on the mechanical properties of reinforced polypropylene composites and modeling of the properties

This work was centered on investigating the influence of mercerization treatment of sisal fiber on the mechanical properties of reinforced polypropylene (PP) composites and modeling of the mechanical properties. The sisal fiber was sourced from their plantation and was extracted by soil retting process. The extracted fibers were divided into three from where two parts were subjected to mercerization treatment with sodium hydroxide (NaOH) and potassium hydroxide (KOH) in a shaker water bath at 50°C for 4 hours respectively. The third part was left as untreated fibers. Both the treated and untreated fibers were cut into 10 mm lengths and were used for the production of the composites. The fibers and the polypropylene were blended in predetermined proportions in a randomly dispersed mode and were subjected to heat and pressure in a heating compression molding machine maintained at 170°C for 10 minutes. Tensile and flexural properties were observed from universal testing machine and a mathematical response surface methodology model (RSM) was developed. From the flexural and tensile results, it was observed that, KOH treated sisal fiber reinforced polypropylene composites gave the best flexural and tensile properties when compared to NaOH treated sisal fiber reinforced polypropylene composites and untreated sisal fiber reinforced polypropylene composites. The developed RSM models reveal high degree of correlation between the experimental values and the predicted values. This implies that, the model can be used to predict the mechanical properties of the sisal fiber reinforced polypropylene composite materials.