Effect of dissolution time and recycled solvent on the nanowelding process of cellulose nanofiber

In this study, all-cellulose nanocomposite was prepared through partial dissolution-nanowelding of cellulose nanofibers (prepared from Nano Novin Polymer Co.) using ionic liquid and the effect of dissolution time and recycled solvent on nanowelding process and nanocomposite properties was investigated. Also, six times of 5, 10, 20, 30, 60 and 120 min were used as dissolution times to partially dissolve cellulose nanofibers. Results showed that with increasing dissolution time, crystallinity increased and crystallite size decreased. FE-SEM micrographs confirmed that increasing dissolution time led to decrease in nanofiber diameter and increase of welding area. With the increase of dissolution time, tensile strength and Young’s modulus increased. But, these mechanical properties dropped over dissolution time longer than 30 min. However, the longer dissolution time, the higher strain at break. Since all-cellulose nanocomposite prepared with dissolution time of 30 min showed highest mechanical properties, recycled solvent was also used just for 30 min as dissolution time to partially dissolve cellulose nanofibers. The results of this section showed that nanocomposite prepared with as-received solvent had similar properties with that of prepared by recycled solvent.