Hidrogeis Nanocompositos de Alginato/ Nanocelulose/Bixina

This work reports the results for the synthesis of the nanocomposite hydrogel of alginate/nanocellulose/ bixin and their characterization by scanning electron microscopy, thermal analysis, degree of swelling, gel fraction and mass loss. Bixin was extracted from the seeds of Bixa orellana L., popularly known as annatto, and nanocellulose was produced from sugarcane bagasse. The methodology used in the purification of bixin was crystallization/recrystallization, with a yield of 9.4% relative to the annatto extracted from the seeds. Analysis by infrared spectroscopy and by high performance liquid chromatography indicated that the bixin had high purity. Nanocelluloses were obtained by pulping, bleaching and acid hydrolysis of sugarcane bagasse fiber. The nanocomposites of alginate/nanocelluloses/bixin showed swelling behavior at neutral and alkaline media, but no swelling was observed at acid medium. Moreover, the presence of nanocellulose and/or bixin decreased the degree of swelling, indicating their incorporation at the alginate matrix. According to the SEM micrographs, porosity was observed in the nanocomposite morphology, indicating the possibility of the incorporation of macromolecules, tissue and cells. DTA-TG curves indicated that the nanocomposite showed good thermal stability until 200 oC and the DSC indicated that the vitreous transition and the melting temperatures of the nanocomposites were 148 and 294 oC, respectively.