Cellulose nanocrystal effects on the biodegradability with alginate and crude seaweed extract nanocomposite films

Degradability of alginate and crude seaweed extract bionanocomposite films were used to study the effect of cellulose nanocrystals (CNC) on biodegradation. CNC were successfully isolated from brown seaweeds, kombu (Laminaria japonica) and sargassum (Sargassum natans). Degradability was measured using weight loss with an indoor soil burial and lake water immersion tests for 35 days each. With the addition of CNC, alginate nanocomposite films showed lower weight lost than pure alginate films with 13.6% in soil burial and 19.9% in lake water immersion which indicated higher stability. In the case of kombu and sargassum films, stability of films increased 9.3 and 11.9% in soil burial and lake water immersion with CNC, respectively. Morphological observations with scanning electron microscopy showed wrinkles, pores, and cracks of the films after soil burial and lake water immersion. Chemical structure analysis showed that the molecular interactions in the polymer matrix diminished after the degradation tests. Thermogravimetric analysis was used to determine the thermal stabilities of nanocomposite films. The study showed that the alginate and crude seaweed extract bionanocomposite films reinforced with CNC can increase the polymer matrix interactions which led to higher stability in soil burial and lake water immersion tests.