Preparation and Properties of Acetylated Cellulose Nanocrystals/Poly(butylene succinate-co-butylene adipate) Composites

Acetylated cellulose nanocrystals (ACNC) were prepared by surface modifying cellulose nanocrystals (CNC) with acetic anhydride (AA). By adding ACNC into biodegradable poly(butylene succinate-co-butylene adipate) (PBSA), ACNC/PBSA composites were prepared via a melt blending method. The structure and morphology of the ACNC were analyzed by Fourier transform infrared (FTIR) spectroscopy, wide angle X-ray diffraction (WAXD) analysis, field emission scanning electron microscopy (FE-SEM) and contact angle measurements. The results showed that the CNC were successfully modified by acetic anhydride, while maintaining their original nanosize rod shape of CNC and showing obvious hydrophobicity. SEM images of the ACNC/PBSA composites indicated that the ACNC were homogeneously dispersed in the composites. With increasing ACNC content, the crystalinity, melt viscosity and decomposition starting temperature increased gradually. In addition, the tensile strength of the ACNC/PBSA composites showed a maximum value at a ACNC content of 3.0%, which was 26.3% higher than for pristine PBSA but the elongation at break was 20% lower than for pristine PBSA.