Síntese de biopolímeros a partir de resíduo madeireiro na Amazônia.

Abstract

The furniture industry produces a large amount of wood waste every year, without proper disposal. Due to the great abundance and the impact generated by the inadequate disposal of these residues, this study aimed to give an adequate destination to wood residues through the extraction of lactic acid for subsequent conversion into biopolymer. Residues from muiracatiara (Astronium lecointei) and cedar (Cedrela odorata) species were used, comparing them in terms of their chemical characterization and conversion into lactic acid, identifying the best source for transformation into biopolymers. In lignocellulosic biomass are found the major components: cellulose, hemicellulose and lignin, with cellulose and hemicellulose being the target of this study. The residue of these species was mechanically processed by shear and later submitted to chemical pulping and acid hydrolysis processes to transform its lignocellulosic biomass to the glucose fraction. This glucose then underwent lactic fermentation via Lactobacillus casei and Saccharomyces cerevisiae in order to produce lactic acid. Lactic acid formation was evaluated for 3 periods, 24, 48 and 72 hours. This chemical compound then underwent the polymerization process by direct polycondensation (PD), through the addition of sulfuric acid to produce the biopolymers. The obtained crystals were subjected to infrared and XRD analyses. Through this study, amorphous biopolymers were obtained, but with good quality characteristics for hydroxyapatite. Regarding the lactic acid yield, it showed similar amounts for the 24 and 48 hours times, with better peaks at 48 hours, and a lower yield at the 72 hours, as for the lactic acid obtained from S. cerevisae and from L. casei; there was no significant difference between the different species studied. For commercialization, the polymers still need to go through purification and refinement processes with a view to their application in orthotics, such as dental grafts.