Obtaining Composite Materials as an Alternative Use of Pineapple Residual Biomass for the Generation of Polymers Reinforced with Natural Fibers

Abstract

One of the biggest problems in agricultural crops in general and, given its agronomic characteristics, in the pineapple crop, is the disposal of harvest residues. Currently, residues are removed and deposited in areas adjacent to the crop, becoming a focus of insect pests and diseases. Given the above context, the use of the afore mentioned foliar residues was evaluated as an alternative for obtaining composite materials from the plant's leaf fiber, thus generating added value to this residue. Initially, the leaves were subjected to three treatments to verify the effect on the tensile characteristics of the fibers. The treatments consisted of subjecting the leaves to fermentation at two temperatures (ambient and 30 °C) and in the presence of a NaOH solution [5%]. Subsequently, composite briquettes were made from pineapple fibers in proportions of 20 % and 30 % mixed with glycerol, guar gum, magnesium stearate and starch, evaluating the effect of the concentration of these fibers on the physico-mechanical properties of tension and elongation. Likewise, the effect of the use of a nanoclay in concentrations of 2.5 % and 5 % as reinforcement of the composite materials in a mixture with a fiber percentage of 20 % and 30 % was evaluated. In fermentation, significant differences (P>0.5) were found between the treatments, verifying that the best pretreatment was presented by the fermentation at room temperature with stress values of 373.33 ± 10.67 MPa, followed by the treatment at a temperature of 30 °C with 261.33 ± 23.09 MPa. On the other hand, when evaluating the tension and elongation, significant differences (P>0.5) were found between treatments, reporting values of 0.51 ± 0.03 MPa and 0.18 ± 0.0028 MPa for fiber concentrations of 20 % and 30 %, respectively. The effect of the use of nanoclay evidenced a higher strain in the treatment with 30 % fiber and 5 % nanoreinforcement with a value of 0.15 ± 0.0172 MPa.