Abstract Curdlan alkylcarbamate (CrdC) with a degree of substitution (DS) of ~2 was chemically modified via postesterification using carboxylic anhydride at a residual OH. Fully substituted mixed esters of curdlan carbamate/carboxylate (CrdCE) (DS = 3) with carbamate hydrogen bonding ability were obtained in high yields (>80). Owing to replacing the residual OH with alkanoates, the glass transition temperature of CrdCE was lower than that of the corresponding CrdC. All the CrdCE displayed a greater deformability evaluated by elongation at break, being more remarkable when introducing longer esters (almost two times higher than the unmodified CrdC) than shorter esters (1.4 times higher). On the other hand, the effect on both Young's modulus and tensile strength depended on the length of the esters, observing an increase on both parameters when using shorter esters (19 and 17 higher, respectively), and a decrease for longer esters (33 and 6 lower, respectively). Thus, it was established that the physical properties of the thermoplastic CrdC could be controlled by modifying the residual OH with an appropriate ester group.
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