Effect of Acetylation with Perchloric Acid as Catalyst in Sugarcane Bagasse Waste
Nycolle G. S. Silva, Tatiana Faria Maia, Daniella R. Mulinari
Abstract
Sugarcane bagasse is used as a byproduct of agro-industrial production. However, natural fibers’ hydrophilic characteristics prevent their application in natural fiber/polymer composites due to the hydroxyl groups (–OH) presented in the cellulose molecule. Because of this, several treatments have been proposed. In this research, the acetylation’s influence on sugarcane bagasse fiber’s structure and properties was investigated, and the effect of the amount of perchloric acid as the catalyst to isolate the lignin and decrease its polarity. Sugarcane bagasse fiber was chemically characterized after modification by Fourier Transform Infrared (FTIR) spectroscopy and degree of substitution (DS). Surface morphology, crystallinity, and thermal stability of fibers were evaluated by Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Thermogravimetry (TGA). A small amount of catalyst content has a significant effect on the DS, causing improved surface morphology and increased thermal stability due to acetylation. However, the crystallinity and lignin content of the fibers decreased after acetylation. According to chemical composition, the crystallinity decreased due to the amorphous phase from hemicellulose deposition. The decrease in the crystalline cellulose enhanced the acetylation reaction and substituted more hydroxyls groups per glucose unit according to DS values. Thus, the catalyst has an essential role in the efficiency of acetylation with sugarcane bagasse fiber.