Charging Behavior and Stability of the Novel Amino Group Containing Cellulose Ester Cellulose‐4‐[N‐methylamino]butyrate Hydrochloride

The charging behavior of water-soluble cellulose-4-[N-methylamino]butyrate hydrochloride (CMABH) with different degree of substitution (DS) is investigated by polyelectrolyte titration at different pH values. Samples of high DS (0.92) and low DS (0.31) exhibit a decrease in positively charged groups from pH 2 (3.9 and 1.9 mmol g−1) to pH 9 (0.81 and 0.65 mmol g−1) due to the deprotonation of the ammonium groups. The stability of the ester linkage of CMABH is examined as a function of pH value and storage time (up to 28 d). A hydrolysis of the ester moiety is evident after 2 h at pH 8, which is also proved by ATR-FTIR- and Raman spectroscopy.