用含有二硫化物固化剂制备环氧树脂及其在自愈涂层中的应用
Baolei Wang1, Zewei Li1, Xinru Liu1
1Beijing Key Laboratory of Special Elastomeric Composite Materials, Beijing Institute of Petrochemical Technology, College of New Materials and Chemical Engineering, Beijing 102617, China.
Materials (Basel, Switzerland)
|June 28, 2023
概括
这项研究引入了一种新型的自我修复环氧树脂,使用二硫化物键进行可重复的裂纹修复. 优化的配方实现98%的愈合效率和增强的耐腐蚀性,延长涂层寿命.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物化学 聚合物化学
- 纳米技术 纳米技术
背景情况:
- 动态共价键使具有可重复性质的内在自我修复的聚合物成为可能.
- 环氧树脂被广泛使用,但缺乏固有的自我愈合能力.
- 开发自愈材料对于延长产品寿命和减少浪费至关重要.
研究的目的:
- 通过使用含有二硫化物的化合物合成一种新型的自我修复环氧树脂.
- 研究聚合物网络结构对自我愈合性能的影响.
- 为了评估开发的树脂的机械性能,自我修复效率和耐腐蚀性.
主要方法:
- 通过凝结二甲基3,3'-二二二 propionate (DTPA) 和聚胺 (PEA) 来合成环氧树脂.
- 将柔性分子链和二硫化物键融入交联的聚合物网络中.
- 在温和条件下 (60°C6小时) 具有自我愈合特性.
- 机械测试,包括最终延长测量.
- 使用浸泡试验和电化学阻抗光谱 (EIS) 评估耐腐蚀性.
主要成果:
- 合成的环氧树脂表现出由二硫化物键触发的内在自我愈合特性.
- PEA与DTPA的最佳摩尔比率 (2:1) 产生了高的终极延伸 (795%) 和愈合效率 (98%).
- 柔性细分,二硫化物和键的分布影响了自我愈合.
- 自愈涂层表现出良好的耐腐蚀性.
结论:
- 开发了一种简单,低成本的方法来生产自我修复的环氧涂层.
- 这种新型树脂通过裂自我修复延长了传统环氧涂料的使用寿命.
- 这项研究为具有更强耐久性的先进防护涂层提供了有前途的方法.
相关概念视频
02:33Preparation and Reactions of Thiols
6.4K
Thiols are prepared using the hydrosulfide anion as a nucleophile in a nucleophilic substitution reaction with alkyl halides. For instance, bromobutane reacts with sodium hydrosulfide to give butanethiol.
6.4K
01:26Curing Methods
102
Concrete members with a small surface-to-volume ratio are cured by oiling and moistening the forms before casting the concrete member. These forms can be left in place for a prolonged period to prevent moisture loss, and can be wetted if made of a material suitable for wetting. If the forms are removed early, the concrete member is moistened and covered with polythene sheets to maintain moisture. For large horizontal concrete surfaces exposed to dry weather, a temporary covering is suspended...
102
01:20Curing of Concrete
124
The hydration of cement takes place within the water-filled capillary pores. However, environmental elements can disrupt this process by evaporating water from the concrete surfaces. Sealed concrete with a water-cement ratio below 0.5 experiences self-desiccation, leading to water loss. The water loss in concrete is mitigated by curing. This technique involves keeping the concrete saturated to maintain the necessary temperature and moisture conditions, to optimally fill the spaces in the cement...
124
02:26Preparation and Reactions of Sulfides
4.9K
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
4.9K
01:25Accelerated Curing of Concrete
192
Accelerating concrete curing is achieved by applying heat and additional moisture. This process accelerates the hydration of the cement, resulting in an earlier strength gain in the concrete. Steam curing is a method wherein the concrete products are either transported through a chamber on a conveyor belt or encased in plastic, allowing steam at atmospheric pressure to circulate freely around them. This process begins with a phase of moist curing that typically lasts between 3 to 5 hours, after...
192
03:00Preparation of Epoxides
7.9K
Overview
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
7.9K