Abstract: A new system of pH-sensitive hydrogels composed of collagen，poly(vinyl pyrrolidone) (PVP) and acrylamide (AM) were prepared by grafting copolymerization in the presence of initiator H₂O₂ under ultraviolet (UV). The conditions of synthesis，such as mass ratio of monomer，and different dry method，were investigated. The hydrogels synthesized displayed good swelling behavior in water，its absorbency can get up to about 94% in 5 minutes. The measurements of the hydrogels showed that they exhibited obviously pH sensitivity and were stable after repeated pH swelling experiments. The molecular structure of the hydrogels was studied with Fourier Transform Infrared Spectroscopy (FTIR) and their thermal behavior was investigated by Differential Scanning Calorimetry (DSC). The results showed that chemical cross-linking took place between these three materials on basis of keeping the triple helix of collagen and thermal stability of hydrogels was improved obviously.

摘要： 在紫外光辐照下，以H2O2为引发剂，采用接枝共聚法制备胶原/聚乙烯吡咯烷酮/丙烯酰胺（Collagen/PVP/AM）pH敏感水凝胶。考察了原料配比和干燥方法对凝胶溶胀性能的影响，研究了其pH敏感性及pH溶胀-退胀特性。制备的水凝胶具有较快的溶胀速率，在5 min时的吸水率可达94％左右。所制备的水凝胶有明显的pH敏感性且pH溶胀-退胀的可逆性良好。傅里叶变换红外光谱法（FTIR）和示差扫描量热法（DSC）结果表明，在保持胶原三股螺旋结构的同时，材料间发生了化学交联，材料的热稳定性显著提高，从而扩大了材料的应用范围。