聚丙烯酰胺水凝胶相关问题的研究.pdfVIP

摘 要 分别采用光引发与溶液聚合的方法合成了聚丙烯酰胺凝胶 并且采用原位聚合制 备了聚丙烯酰胺/纳米SiO2 复合凝胶 分析了各种因素对凝胶性能的影响 并采用DSC DMA 对复合凝胶的热性能及动态机械性能进行了分析 在光引发聚合中 分别在聚合物基底 PET PS 薄膜 及硅片上制备了聚丙烯 酰胺凝胶 发现凝胶的成胶时间 表面形貌等强烈的依赖于基底的性质 在亲水性的 基底上凝胶成胶时间较疏水性的短; 凝胶的溶胀率不仅与光照时间 交联剂的含量等 因素有关 而且与基底也有很大关系 在亲水性的基底上形成的凝胶平衡溶胀率小于 在疏水性的基底上制备的凝胶 在溶液聚合中 合成的聚丙烯酰胺凝胶的透明性随交联剂含量的增加明显下降 凝胶的平衡溶胀率不仅与交联剂的含量有关 而且与温度 pH 值 离子强度的变化也 相关 凝胶的平衡溶胀率随交联剂含量的增加而大幅下降 随着温度的提高溶胀率略 有上升 在 pH 值为 5.03 溶液中的平衡溶胀率达到最小值 另外 它还随着离子强度 的增加而明显增大 利用原位聚合的方法合成了一系列的聚丙烯酰胺/纳米SiO2 复合凝胶 测试结果显 示 凝胶化过程中红外光谱部分峰值发生偏移 DSC 中峰值对应的温度有所提高 这 可能是由于纳米粒子与丙烯酰胺分子之间存在有氢键或其它化学作用所致 复合凝胶 的溶胀率随着纳米粒子含量的增多略有降低 而退溶胀速率却明显提高 而动态粘弹 谱则显示了复合凝胶的储能模量与纳米粒子的种类 含量以及交联剂含量有关 关键词: 聚丙烯酰胺凝胶,光引发, 溶胀性能,动态机械性能 I ABSTRACT In this study, Polyacrylamide (PAAm) hydrogels and Polyacrylamide/silica composite hydrogels were synthesized using UV induced polymerization and in-situ free-radical polymerization respectively. Various factors on hydrogels preparation were studied and the hydrogels were characterized by optical microscopy (OM), scanning electron microscopy (SEM), Fourier transform IR (FTIR), differential scanning calorimetry (DSC), dynamic mechanical analyzer (DMA), etc.. To get the influence of the substrate on the properties of the resulted hydrogel, the UV polymerized PAAm hydrogels were synthesized on substrates (PET, PS film and silicon wafer) with different properties. It was found that the properties of hydrogels such as gelation times, surface morphology, stability, and swelling behavior strongly depended on the substrates : the gelation time prepared on hydrophilic substrate (PET film and silicon wafer) was shorter than that made on the hydrophobic substrate (PS film). The swelling behavior was not only affected by UV-exposure time and content of cross linking agent but also by the properties of the substrates