基于超支化聚合物的高强仿贝壳复合材料

发布时间：2018-02-04 08:48

本文关键词： 超支化聚合物仿贝壳高强度高韧性交联　出处：《合肥工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：贝壳具有优异的性能,如质轻,强度大和韧性高,这些都可归因于贝壳独特的“砖”和“泥浆”的层状结构。受贝壳多层次结构的启发,人们已经可以用许多方法来制备高强度仿贝壳复合材料。然而,目前人们虽然在制备高强度仿贝壳材料方面取得了很大进展,但是高韧性的仿贝壳材料却不多见。因此,如何制备兼具高强度与高韧性的仿贝壳材料仍是一项挑战。研究分析表明,以往制备仿贝壳材料大多数选用的是线性聚合物,如聚乙烯醇(PVA),聚甲基丙烯酸甲酯(PMMA),聚二烯丙基二甲基氯化铵(PDDA)壳聚糖等。这些线性聚合物带有大量极性基团,可与无机片层材料形成强的氢键,因而制备的复合材料强度大。但由于这些线性聚合物分子是由共价键连接而成,共价键不能可逆断裂、重组,使得能量耗散过程不可分阶段完成,因而韧性较低。面对这个问题,有望通过引入动态相互作用(如氢键、π.π相互作用、范德华力、离子键等)来解决这一问题。脂肪族超支化聚合物的结构特点非常适合制备高韧复合材料。一方面,脂肪族超支化聚合物分子结构中通常具有大量的极性基团,如氨基、酰胺基、羟基等、易于形成分子内与分子间的氢键作用；另一方面,脂肪族超支化聚合物的分子结构高度支化、内部空腔大、自由体积大,因而分子运动能力强,即便是被夹在片状增强材料之间,也会具有很强的运动能力。这些都具备了形成动态相互作用的基础。为了进一步获取高强高韧的超支化聚合物仿贝壳复合材料,有必要对复合材料加以适度交联。有许多仿贝壳复合材料方面的研究报道表明,交联后复合材料的力学强度将会有大幅度提高。因而,可以预期在将超支化聚合物复合材料交联后,有望获得高强、高韧的仿贝壳复合材料。本论文中,首先,以亚甲基双丙烯酰胺和1-(2-氨乙基)哌嗪为单体,经迈克尔加成反应合成了超支化聚合物聚酰胺.胺(HPAMAM),并将其分别与纳米粘土(clay),氧化石墨烯(GO)进行组装制备仿贝壳材料,得到了具有层状结构的HPAMAM/clay复合膜和HPAMAM/GO复合膜。在此基础上,用京尼平进行了交联。这些复合膜都具有很高的强度和很高的韧性。对于京尼平交联的G-HPAMAM/clay复合体系,拉伸强度达到了159MPa,韧性高达2.5MJ·m3：对于京尼平交联G-HPAMAM/GO复合体系,拉伸强度为165MPa,断裂伸长率大于10%。这种复合膜由于各组分良好的生物相容性,在生物医疗研究中有很重要的潜在应用,如组织工程,韧带替代或骨修复。
[Abstract]:Shell has excellent performance, such as light weight, high strength and high toughness, which can be attributed to the shell's unique "brick" and "mud" layer structure. Many methods have been used to fabricate high strength shell-like composite materials. However, at present, great progress has been made in the preparation of high strength shell-like materials. However, there are few shell imitating materials with high toughness. Therefore, it is still a challenge to prepare shell imitating materials with both high strength and high toughness. In the past, most of the shell-like materials were made from linear polymers, such as polyvinyl alcohol (PVA), polymethyl methacrylate (PMMA). Poly (diallyl dimethyl ammonium chloride) chitosan. These linear polymers have a large number of polar groups and form strong hydrogen bonds with inorganic lamellar materials. However, because these linear polymer molecules are covalently bonded, the covalent bond can not be broken and recombined, which makes the energy dissipation process can not be completed in different stages. In the face of this problem, it is possible to introduce dynamic interactions (such as hydrogen bond, 蟺. 蟺 interaction) and van der Waals force. The structural characteristics of hyperbranched aliphatic polymers are very suitable for the preparation of high toughness composites. On the one hand, there are usually a large number of polar groups in the molecular structure of aliphatic hyperbranched polymers. Such as amino, amide, hydroxyl and so on, easy to form intramolecular and inter-molecular hydrogen bond; On the other hand, the molecular structure of hyperbranched aliphatic polymers is highly branched, the internal cavity is large, and the free volume is large, thus the molecular motion is strong, even if it is sandwiched between the flake reinforcement materials. These have the basis of forming dynamic interaction. In order to further obtain high strength and high toughness hyperbranched polymer shell imitation composite. It is necessary to make appropriate crosslinking of composite materials. There are many research reports on shell imitation composite material, which shows that the mechanical strength of the composite will be greatly improved after crosslinking. It can be expected that the hyperbranched polymer composites can be crosslinked to obtain high strength and high toughness shell imitation composites. The hyperbranched polymer polyamide (HPAMAM) was synthesized by Michael addition reaction using methylene bisacrylamide and 1-methylene 2-aminoethyl) piperazine as monomers. It was assembled with nano-clay clayer and graphene oxide to prepare shell-like materials. HPAMAM/clay and HPAMAM/GO composite membranes with layered structure were obtained. These composite membranes have high strength and toughness. The tensile strength of genipine crosslinked G-HPAMAM / clay composite system is 159MPa. The toughness is up to 2.5MJ 路m3: for genipine crosslinked G-HPAMAM / go composite system, the tensile strength is 165MPa. The composite membrane has important potential applications in biomedical research, such as tissue engineering, ligament replacement or bone repair because of its good biocompatibility.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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