Abstract: A polyelectrolyte complexed product——N-carboxyethylchitosan (ACS) was prepared through the Michael reaction between chitosan and acrylic acid，whose structure was confirmed by FTIR spectra and 1H NMR spectra. The pH-sensitivity and swelling behavior of the ACS hydrogel (ACSG) were studied. The results showed that carboxyethyl group was grafted onto the chitosan molecule by the Michael reaction. ACSG was strongly pH-sensitive，and the acidic pH-sensitivity was higher than the basic pH-sensitivity. The swelling behavior of ACSG was different in different buffer solutions. ACSG exhibited better swelling behavior not only in acidic but also in basic conditions，and the smallest swelling ratio (SR) was obtained in pH 5.0 buffer solution. With the increase of glutaraldehyde dosage，the SR of ACSG decreased in different pH buffer solutions. With increasing degree of substitution of carboxyethyl group，SR increased at first and decreased afterward.

摘要： 利用迈克尔加成反应制备了两性聚电解质物质——丙烯酸接枝壳聚糖（ACS），利用FTIR和1H NMR对ACS进行结构表征，制备了丙烯酸接枝壳聚糖水凝胶（ACSG），并研究其pH敏感性和溶胀行为。结果如下：通过迈克尔加成反应，在壳聚糖分子链上引入了羧乙基基团；ACSG在pH值1.2～9.0溶液中均有较强的pH敏感性，酸敏性优于碱敏性；ACSG在不同pH值溶液中的溶胀行为各不相同，在偏酸和偏碱性时溶胀度较大，pH值5.0时溶胀度最小；随着交联剂用量的增加，ACSG的溶胀度逐渐降低；随着取代度的增大，ACSG的溶胀度则先增大后减小。