Abstract In this research, three modified chitosan-based hydrogels are synthesized, i.e., a crosslinked chitosan hydrogel and semi- and fully-interpenetrating polymer network (IPN) chitosan hydrogels fabricated using poly(N-vinyl-pyrrolidone). A non-modified chitosan hydrogel was also synthesized as a control. These samples were compared regarding their swelling behavior and mechanical properties. The hydrogels were characterized by Fourier Transform Infrared (FTIR) analysis and microscopy observations. The effect of crosslinking on the swelling capacity and on the swelling kinetics were evaluated in distilled water, simulated gastric fluid (SGF), and simulated intestinal fluid (SIF) at 37 °C, and the data were interpreted using various kinetic models. Finally, the mechanical properties were evaluated based on the tensile strength using a universal tensile testing machine. The results revealed that the swelling process conformed to the Schott model (pseudo-second-order kinetics), with Fickian diffusion as the diffusion mechanism type. The hydrogels all showed similar trends in their swelling kinetics. However, the full-IPN hydrogel exhibited the lowest equilibrium swelling capacity and the highest swelling rate. The mechanical test results indicate that the crosslinking model affects the resulting tensile strength.

中文翻译：

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壳聚糖-聚（N-乙烯基-吡咯烷酮）水凝胶的溶胀行为和力学性能

摘要 本研究合成了三种改性壳聚糖基水凝胶，即交联壳聚糖水凝胶和使用聚（N-乙烯基-吡咯烷酮）制备的半互穿和全互穿聚合物网络（IPN）壳聚糖水凝胶。还合成了未改性的壳聚糖水凝胶作为对照。比较这些样品的溶胀行为和机械性能。水凝胶的特点是傅里叶变换红外 (FTIR) 分析和显微镜观察。交联对溶胀能力和溶胀动力学的影响在蒸馏水、模拟胃液 (SGF) 和模拟肠液 (SIF) 中在 37 °C 下进行评估，并使用各种动力学模型解释数据。最后，使用万能拉伸试验机根据拉伸强度评价机械性能。结果表明，溶胀过程符合Schott模型（伪二级动力学），Fickian扩散为扩散机制类型。水凝胶的溶胀动力学均显示出相似的趋势。然而，全IPN水凝胶表现出最低的平衡溶胀能力和最高的溶胀率。机械测试结果表明交联模型会影响最终的拉伸强度。全IPN水凝胶表现出最低的平衡溶胀能力和最高的溶胀率。机械测试结果表明交联模型会影响最终的拉伸强度。全IPN水凝胶表现出最低的平衡溶胀能力和最高的溶胀率。机械测试结果表明交联模型会影响最终的拉伸强度。