新型聚丙烯酰胺水凝胶的制备与性能

发布时间：2018-05-17 02:23

  本文选题：聚丙烯酰胺水凝胶 + 自修复水凝胶　； 参考：《中国科学技术大学》2017年硕士论文

【摘要】：聚丙烯酰胺(PAM)水凝胶在药物控释、组织工程、物质分离、工农业、石油化工、机械器件等方面都有着广泛的应用前景。但是传统方法制备的PAM水凝胶力学性能不佳,缺乏功能基团,使其应用范围受到极大的限制,因此设计和制备新型结构的聚丙烯酰胺水凝胶及其功能化一直以来都是水凝胶领域的热门研究课题。本论文工作针对不同使用环境中传统PAM水凝胶强度弱、易被破坏的缺点,设计制备了三种不同交联形式的高强度PAM基水凝胶,即温敏性自修复聚丙烯酰胺水凝胶、原位热交联型聚丙烯酰胺水凝胶以及"活性"聚合物纳米粒子增强聚丙烯酰胺水凝胶,并对其力学性能进行了表征。具体研究内容如下:1.乳液聚合法一步制备温敏性自修复聚丙烯酰胺水凝胶。首先合成了侧基易于形成氢键的乙烯基共聚单体5-乙酰氨基丙烯酸戊酯(AAPA),然后将AAPA、丙烯酰胺(AM)和甲基丙烯酸十二烷基酯(DM)按一定比例与含有乳化剂十二烷基硫酸钠(SDS)的水溶液混合形成乳液,以过硫酸铵(APS)和四甲基乙二胺(TEMED)为引发剂体系,室温下一步反应得到自修复聚丙烯酰胺水凝胶,该凝胶的弹性模量高达400 Pa。疏水链段在疏水缔合作用下发生相分离形成可控的物理交联点,当温度升高到70℃时,凝胶会发生凝胶-溶胶转变。将断裂的凝胶断面接触,2 min内断裂的凝胶能够回复到原始强度95%以上。2.原位热交联型聚丙烯酰胺水凝胶的制备。在四氢呋喃中通过自由基溶液聚合制备AM和Y-甲基丙烯酰氧丙基三甲氧基硅烷(MPS)的无规共聚物P(AM-co-MPS),将所得共聚物溶于水,能够形成粘度为4～10mPa·s的聚合物水溶液,当P(AM-co-MPS)共聚物水溶液浓度大于10 wt%,且共聚物中MPS的含量高于19 wt%时,可以在50～70 °C下原位交联形成凝胶,强度高达7500 Pa。3."活性"聚合物纳米粒子增强聚丙烯酰胺水凝胶的制备。首先在甲醇中通过可逆加成-断裂链转移(RAFT)聚合制备两亲性嵌段共聚物聚丙烯酸-b-聚苯乙烯(PAA-b-PS),经过在水中透析可自组装形成"活性"聚合物囊泡,乙二醇二甲基丙烯酸酯(EGDMA)溶胀进入囊泡的疏水微区,使得聚合物囊泡成为多功能的交联点,与丙烯酰胺共聚形成高强度水凝胶。研究了不同AM、EGDMA以及纳米粒子浓度对凝胶强度的影响,结果表明这种聚合物纳米粒子增强的水凝胶表现出优异的机械性能,压缩强度和拉伸强度分别高达7 MPa和2 MPa,而且具有良好的抗疲劳性能。
[Abstract]:Polyacrylamide (PAM) hydrogel has a wide application prospect in drug controlled release, tissue engineering, material separation, industry and agriculture, petrochemical, mechanical devices and so on. However, the PAM hydrogels prepared by traditional methods have poor mechanical properties and lack of functional groups, so their application scope is greatly limited. Therefore, the design and preparation of novel polyacrylamide hydrogels and their functionalization have been a hot research topic in hydrogel field. In this paper, three kinds of high strength PAM hydrogels with different cross-linking forms were designed and prepared, that is, thermo-sensitive self-repairing polyacrylamide hydrogels, aiming at the weakness of traditional PAM hydrogels with weak strength and easy to be destroyed in different application environments. In situ thermal crosslinked polyacrylamide hydrogels and "active" polymer nanoparticles were used to enhance polyacrylamide hydrogels and their mechanical properties were characterized. The specific contents of the study are as follows: 1. Temperature-sensitive self-repairing polyacrylamide hydrogels were prepared by one-step emulsion polymerization. A vinyl copolymerization monomer, 5-acetylamyl aminoacrylate (AAPAN), which is easy to form hydrogen bonds on the side group, was synthesized at first. Then, AAPA, AM) and DMMA) were prepared in a certain proportion with the emulsifier dodecyl sulphuric acid. The aqueous solution of sodium disodium (SDS) is mixed to form an emulsion. Using ammonium persulfate (APS) and tetramethyl ethylenediamine (TEMED) as initiators, a self-repairing polyacrylamide hydrogel was obtained at room temperature. The elastic modulus of the gel was as high as 400 Pa. The hydrophobic chain segment is separated by phase separation under hydrophobic association to form a controllable physical crosslinking point. When the temperature rises to 70 鈩，

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