Isolation, characterization and utilization of cellulose from sugarcane bagasse

Cellulose is the most abundant natural polymer on Earth and it is employed in several areas such as paper manufacturing, food and pharmaceutical industries. For obtaining cellulose from a lignocellulosic material is necessary to rupture the complex structure of vegetable cellular wall, removing the hemiceluloses and the lignin. The current research had as goal to isolate, characterize and utilize the cellulose from sugarcane bagasse. In the isolation process, in the following order, it was carried out the stages of treatment with H₂SO₄ (10% v/v) for 1 h at 100ºC _, aiming the hemicellulose removal; alkaline delignification (5% NaOH w/v) for 1 h at 100ºC, for the lignin withdrawal and chemical bleaching with H₂O₂ (5% v/v) for 1h at 70ºC, in order to produce a material with high brightness and high purity in cellulose. The extracted cellulose was characterized using the techniques of X-Ray, DSC and TGA and was employed in the obtainment of cellulose acetate and in process of the enzymatic hydrolysis. Under the carried out conditions, it was possible to extract abaout 95% of lignin and hemicellulose, resulting in a final material with more than 90% of purity in relation to cellulose. The physical characterization showed that the cellulose presented 51,93% of crystallinity and 360ºC as temperature of degradation. The cellulose acetate presented high substitution degree (2.60 in a maximum of 3.00) and similar physical properties than a commercial sample. The final conversion in the enzymatic hydrolysis was 85.86%.