Influence of the maturation time on the physico-chemical properties of nanocellulose and associated constituents isolated from pseudostems of banana plant c.v. Valery

Environmental concerns inherent to the manufacture and disposal of synthetic polymers have generated a strong interest toward renewable polymers. Among these materials, nanocellulose is one of the most studied options due to its mechanical, thermal and biodegradability properties. It is usually isolated from wood. However, the use of non-woody lignocellulosics, such as banana plant wastes, has been reported. Industrial applications of these sources require further analysis, for instance, modifications in composition, morphology and structure of cellulose during plant maturation and their influence on nanocellulose performance. These changes were studied by isolating nanocellulose from banana plant c.v. Valery pseudostems harvested at 8, 16 and 24 weeks. The extracted product was observed by field-emission scanning electron microscopy and transmission electron microscopy, and analyzed by Fourier-transform infrared spectroscopy (FTIR), thermogravimetry and X-ray diffraction. Polydisperse nanosized bundles were observed, their distribution changed with maturation time. The contribution of non-cellulosic constituents to the FTIR spectra increased as well, while the thermal stability decreased. Results indicate that maturation could decrease the thermal stability and allomorph ratio of the sample, modifying the performance of the final product.