Nanocellulose Extraction of Pineapple Leaves for Chitosan-starch Nanocomposites.

Cellulose fibers obtained from waste pineapple leaves were chemically treated with acid hydrolysis for reduction to nanoscale size. Once the cellulose nanofibers were obtained, they were used as a reinforcing material (0.3%-1.0%) of a chitosan-starch matrix. Transmission and scanning electron microscopy was used to check the morphology and reduction of the fiber, with which it was demonstrated that the chemical structure of cellulose was not damaged. Once the composites were obtained, thermal tests were carried out through a thermogravimetric analysis and differential scanning calorimetry, in which it was observed that the thermal stability was not affected by the use of the reinforcement. Fourier transform infrared (FTIR) analysis confirmed interactions between hydroxyl groups and amino groups of polysaccharides. Finally, a dynamic mechanical analysis was performed, in which the increase in the storage module of up to 90% was observed with only 0.7% of the nanofiber reinforcement. Through the results obtained in this research, the use of pineapple leaves as raw material for obtaining cellulose nanofibers is verified, which can be an alternative as a use of matrix reinforcement, suggesting an alternative for the replacement of synthetic reinforcements.