Table 2 shows, there
were no significant differences between the equilibrium
moisture contents of the materials despite the increasing
amount of cellulose nanofibers, as reported elsewhere for
TPS/CNF composites [11,25]. Similar type of behavior was
observed by Mathew and Dufresne 2002 when studying
the moisture absorption of sorbitol plasticized thermoplastic
starch reinforced with cellulose nanowhiskers [35].
When sorbitol is used as the plasticizer, it is believed to restrict
the moisture uptake of thermoplastic starch more
than glycerol due to higher chain length and fewer end hydroxyl
groups [35]. Because sorbitol was also used as the