高强度刺激响应与可愈合水凝胶的制备及其性质研究

发布时间：2018-04-03 15:34

本文选题：水凝胶　切入点：双网络　出处：《长春工业大学》2017年硕士论文

【摘要】：水凝胶是一种具有三维网络结构的高分子材料,具有良好的亲水性和生物相容性,在药物释放、组织工程、人工软骨材料、刺激响应性材料等领域具有良好的应用前景。本文中,我们采用不同的原料和方法制备了两种具有特殊性能的水凝胶,主要研究内容和结论概括如下:(1)采用两步法制备了pH响应的高强度双网络水凝胶,凝胶由硼酸盐交联的羟丙基胍胶网络(HPG)和共价交联的聚丙烯酰胺网络(PAAm)组成。基于双网络水凝胶的能量耗散机制,利用硼酸根(B(OH)4-)能与HPG上的顺式羟基交联的特性,以硼酸盐交联的HPG网络作为第一网络,PAAm作为第二网络,制备的DN水凝胶具有优良的机械性能,断裂强度可以达到843 kPa,断裂伸长率达到1400%。此外,在不同的pH条件下,硼酸盐水解产生的B(OH)4-浓度不同,使HPG网络的交联密度发生变化,凝胶显示出独特的pH响应性。相较于其他已经制备的响应性凝胶,HPG/PAAm凝胶以双网络理论为基础,通过HPG网络的引入,在具有优异的机械性能的同时实现了pH响应性。(2)前期工作制备的HPG/PAAm凝胶具有优异的机械强度和pH响应性,但由于硼酸根与顺式羟基交联的弱可逆性以及PAAm链的化学交联,凝胶只是在小形变过程中显示弱的可恢复性,并不具备宏观的可愈合性。因此,我们在第二个实验体系中作出了新的探索,制备出新型的羟丙基胍胶/N,N-二甲基丙烯酰胺(HPG/PDMA)凝胶,显示高效快速的愈合性能。HPG网络通过链上的羟基之间的氢键形成,PDMA网络在没有化学交联剂的情况下自交联形成,与此同时,HPG网络与PDMA网络之间还存在物理交联作用。基于纳米吸附作用,使用纳米二氧化硅作为可逆交联点,凝胶在室温下可以完全愈合,在2 h时愈合率可以达到102%。
[Abstract]:Hydrogel is a kind of polymer material with three-dimensional network structure, which has good hydrophilicity and biocompatibility. It has a good application prospect in the fields of drug release, tissue engineering, artificial cartilage materials, stimulative responsive materials and so on.In this paper, two kinds of hydrogels with special properties were prepared by different raw materials and methods. The main contents and conclusions were summarized as follows: 1) Two-step method was used to prepare high-strength double-network hydrogels with pH response.The gel consists of hydroxypropyl guanidine gel (HPGs) crosslinked by borate and PAA (a covalent crosslinked polyacrylamide network).Based on the energy dissipation mechanism of double network hydrogels, the properties of borate BOH4) can be cross-linked with cis-hydroxyl groups on HPG. The borate crosslinked HPG network is used as the first network and PAAm as the second network.The prepared DN hydrogel has excellent mechanical properties, the fracture strength can reach 843 KPA, and the elongation at break reaches 1 400.In addition, under different pH conditions, the concentration of BnOH4- produced by the hydrolysis of borate salt water changed the crosslinking density of HPG network, and the gel showed a unique pH response.Compared with other responsive gels that have been prepared, HPG / PAAm gel is based on the theory of double networks and is introduced into HPG networks.At the same time, the HPG/PAAm gel prepared by the previous work of pH responsivity has excellent mechanical strength and pH response, but due to the weak reversibility of borate and cis-hydroxyl group crosslinking and the chemical crosslinking of PAAm chain.Gel only shows weak recoverability in the process of small deformation and does not have macroscopical healing ability.Therefore, we made a new exploration in the second experimental system, we prepared a new type of hydroxypropyl guanidine gel / N-dimethylacrylamide HPG-PDMA-gel.It is shown that the highly efficient and rapid healing properties of the HPG network are formed by hydrogen bonds between the hydroxyl groups in the chain, and the self-crosslinking is formed without the chemical crosslinking agent. At the same time, there is physical crosslinking between the HPG network and the PDMA network.Based on the adsorption of nano-silica, the gel can heal completely at room temperature with nano-silica as the reversible crosslinking point, and the healing rate can reach 102% at 2 h.
【学位授予单位】：长春工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O648.17

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