Synthesis, characterization and stabilization effect of antioxidant-functionalized celluloses

Phenolic antioxidants were immobilized on cellulose nanocrystals and microcrystalline cellulose to reduce their loss. The products were synthesized with antioxidant acid chlorides forming ester bonds, and some additionally grafted with aliphatic acid chlorides to improve their solubility in non-polar polymeric matrices. The products were fully characterized using FT-IR, solid-state NMR, X-ray diffraction, and thermogravimetric analysis. The quantity of grafted groups was determined through alkaline hydrolysis and subsequent titration of the excess of alkali. The stabilization effect of the products was verified by oxidation induction time measurements in squalane. Different mixing ratios to test the influence of stabilizer amount were used. The products are compared and influences on the stabilization effect discussed.