Isolation and characterization of lignin from Moroccan sugar cane bagasse: production of lignin-phenol-formaldehyde wood adhesive.

摘要

Lignin-based materials were isolated from Moroccan sugar cane bagasse after alkaline delignification. Sugar cane bagasse was subjected to hot water (70 degrees C) and alkaline aqueous solutions (15% of sodium hydroxide (NaOH), 98 degrees C) treatments. The dissolved lignin macromolecules were separated and purified. The isolated solid was then characterized by different complementary analysis (FT-IR; 1H, 13C NMR; GPC and TGA). In the present work, the possibility of preparing wood adhesives from bagasse lignin has been explored. The results showed that the delignification with 15% NaOH resulted in yields of cellulose and lignin of 42+or-2.2% and 13+or-1.5%, respectively. The extracted lignin scaffolds exhibits high reactivity due to the high content of hydroxyl group. Their higher molecular weight (2781 g/mol) and good thermal stability (180 degrees C) make them excellent candidates for partial substitution of phenol formaldehyde (PF) resin. A resin formulation in which up to 30% of PF can be substituted by bagasse lignin gave good results and was employed for the elaboration of plywood panels which passed relevant international standard specifications for interior-grade panels.