Obtenção de celulose e nanocelulose a partir de biomassas marinhas e linho neozelandês

Abstract

Nonrenewable resources, such as petroleum, are finite, and as oil reserves are about to be depleted over the next century, alternatives based on renewable sources, like biomass, must be explored to replace petrochemicals. However, it is necessary to use alternative sources that will not compete with cropped areas. Thus, the present work explored the viability of biomasses (New Zealand flax and seaweed from the Antarctic and Sub-Antarctic regions) to obtain cellulosic material. Hence, the mentioned biomasses were ground and subjected to chemical and physical treatments (alkaline hydrolysis (NaOH 5% w/v), bleaching (NaClO2) and sonication) to obtain cellulosic material. The feasibility to converting cellulosic materials into nanocellulose through an acid hydrolysis and cellulose acetate by esterification reaction was also evaluated. The obtained materials were chemically characterized, according to Technical Association of the Pulp and Paper Industry standards (Tappi), by Fourier transform infrared spectroscopy, and by carbon 13 nuclear magnetic resonance spectroscopy; physically characterized by zeta potential, thermogravimetry and differential scanning calorimetry; morphologically characterized by optical microscopy, scanning electronics microscopy, Field Emission Scanning Electron Microscopy and transmission electron microscopy. In addition, the materials were characterized by X-ray diffraction and cell viability according to ISO 10.993-5. As result, cellulose nanofiber like-sponge morphology was produced from the algae Cystosphaera jacquinotti, without acid hydrolysis. The material being an excellent substrate for cell proliferation. Cellulosic material like-sponge morphology was produced from Anhfeltia plicata. In addition, New Zealand flax was an excellent source of cellulose, presenting a high yield and can be used to produce cellulose nanofibers, by acid hydrolysis and cellulose acetate by esterification.