Most amino acid molecules have good water solubility and are rich in functional groups, which makes them a promising derivatizing agent for cellulose. However, self-condensation of amino acids and low reaction efficiency always happen during esterification. Here, amino acid hydrochloride ([AA]Cl) is selected as raw material to synthesize cellulose amino acid ester (CAE). Based on TG-MS coupling technology, a significantly faster reaction rate of [AA]Cl compared to raw amino acid can be observed visually. CAE with the degree of substitution 0.412-0.516 is facilely synthesized under 130-170 °C for 10-50 min. Moreover, the effects of amounts of [AA]Cl agent, temperature, and time on the esterification are studied. The CAE can be well dissolved in 7 wt% NaOH aq., resulting in a 7.5 wt% dope. The rheological test of the dope demonstrated a shear-thinning behavior for Newtonian-like fluid, and a high gel temperature (41.7 °C). Further, the synthesized products show distinct antibacterial activity and the bacteriostatic reduction rate against E. coli can reach 99.5 %.
Keywords: Amino acid hydrochloride; Antibacterial activity; Cellulose; Esterification; Solubility.
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