Synthesis and oxidative stability of phenolic antioxidants immobilized by cellulose nanocrystals
Sprache des Titels:
Englisch
Original Kurzfassung:
Antioxidants are immobilized by attaching them as functional groups to cellulose nanocrystals. The
synthesis route includes a carboxymethylation step followed by covalent grafting of di-
tert
-butylphenol
moieties (
fi
rst product). To improve solubility within non-polar polymeric matrices additional octadecyl
groups are added (second product). Both products are fully characterized using FT-IR, solid-state NMR,
and thermogravimetric analyses. The degree of substitution in each functionalization step is determined
by conductometric titration. The syntheses are successful, with moderate degrees of functionalization
due to limited accessibility of the hydroxyl groups, which correlates with the geometric shape of cel-
lulose nanocrystals. The stabilization effect is determined by oxidation induction time measurements in
squalane. Further, the in
fl
uence of additional octadecyl moieties grafted to cellulose nanocrystals is
assessed