Effect of tertiary amine catalysts on the acetylation of wheat straw for the production of oil sorption-active materials

Abstract

Dried wheat straw was treated with acetic anhydride at 100 and 120 °C for 40–360 min with four tertiary amine catalysts (pyridine, 4-dimethylamino pyridine, N -methyl pyrrolidine, and N -methyl pyrrolidinone) or without catalyst in a solvent-free system, and the extent of acetylation was measured by weight percent gain. 4-Dimethylamino pyridine was found to be the most effective catalyst of those studied. The characterization of acetylated straw was performed by FT–IR, CP–MAS 13 C–NMR, and thermal studies. FT–IR and CP–MAS 13 C–NMR studies produced evidence for acetylation. The thermal stability of acetylated wheat straw was found to be higher than the native straw. More importantly, the acetylation significantly increased the hydrophobic properties of the straw. The oil sorption capacities of the acetylated straws were much higher (1.2–2.9 times) than the commercial synthetic oil sorbents such as polypropylene fibres. Acetylated straw can therefore be used as a substitute for non-biodegradable materials in oil-spill cleanup. .