相关实验视频
Updated: Jun 28, 2025
08:00
DNA Nanotubes as a Versatile Tool to Study Semiflexible Polymers
Published on: October 25, 2017
6.9K
离子协调折叠基聚合物网络:从分子弹到弹性体
Jiangping Qin1, Yongming Wang2, Tian Wang1
1Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, 710069, Xi'an, P. R. China.
Angewandte Chemie (International ed. in English)
|April 16, 2024
概括
新的聚合物网络模仿了使用基于阳离子协调的折叠体的线圈弹. 这些分子弹提高了材料的能量消耗和性,为高性能聚合物提供了新的设计策略.
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
- 超分子化学 超分子化学
背景情况:
- 折叠体的功能就像分子弹,通过形状变化吸收和释放能量.
- 开发高密度分子弹的聚合物网络对于先进的材料性能至关重要.
研究的目的:
- 设计聚合物网络,使用基于离子协调的折叠聚合物作为单体.
- 为了研究折叠体构成和由此产生的聚合物网络的机械性能之间的关系.
主要方法:
- 合成的聚合物网络包含了与化离子协调的基合物,形成基于离子协调的折叠体.
- 通过连接体设计进行受控的折叠机绕,以实现不同程度的折叠 (非折叠,全转,1.5转).
- 描述了聚合物网络的机械性质 (强度,延长,扬模量,性).
主要成果:
- 机械性能随着折叠机卷轴显著增加:P-L2UCl (非折叠) < P-L4UCl (全转) < P-L6UCl (1.5转).
- P-L6UCl表现出优越的强度 (22.93 MPa),延伸度 (352%),模量 (141.50 MPa) 和性 (49.62 MJ/m3).
- 开发的基于折叠材料的网络表现优于缺乏离子中心和非折叠材料的对应网络.
结论:
- 基于阴离子协调的折叠体有效地作为聚合物网络中的分子弹.
- 折叠机形状是实现高能耗和机械性的关键决定因素.
- 本研究提出了一种可行的策略,用于设计基于离子协调的高性能材料.
更多相关视频
相关概念视频
01:20Anionic Chain-Growth Polymerization: Overview
2.1K
The polymerization process that involves carbanion as an intermediate is called anionic polymerization. It is also a type of addition or chain-growth polymerization. Anionic polymerization gets initiated by a strong nucleophile such as an organolithium or a Grignard reagent. The most commonly used initiator for anionic polymerization is butyl lithium. Monomers involved in anionic polymerization must possess a vinyl group bonded to one or two electron-withdrawing groups. For instance,...
2.1K
01:04Anionic Chain-Growth Polymerization: Mechanism
2.0K
The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic anion, such as butyl lithium, initiates the polymerization process by attacking the π bond of the vinylic monomer. As a result, a carbanion, stabilized by the electron‐withdrawing group, is generated. The resulting carbanion acts as a Michael donor in the propagation step and attacks the second vinylic monomer, which acts as a Michael...
2.0K
00:57Cationic Chain-Growth Polymerization: Mechanism
2.3K
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the...
2.3K
01:17Ziegler–Natta Chain-Growth Polymerization: Overview
3.3K
Ziegler–Natta polymerization is another form of addition or chain‐growth polymerization used for synthesizing linear polymers over branched polymers. The catalyst used for polymerization is the Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, who developed it in 1953. This catalyst is an organometallic complex of titanium tetrachloride and triethyl aluminum, with the active form of the catalyst being an alkyl titanium compound. Using the Ziegler–Natta...
3.3K
01:09Radical Chain-Growth Polymerization: Mechanism
2.5K
The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization initiates when a free radical generated from the radical initiator adds to the unsaturated bond in the monomer. The unpaired electron of the free radical and one π electron in the unsaturated bond creates a σ bond between the free radical and the monomer. As a result, the other π electron in the unsaturated bond converts this...
2.5K
02:34Polymers
35.7K
The word polymer is derived from the Greek words “poly” which means “many” and “mer” which means “parts”. Polymers are long chains of molecules composed of repeating units of smaller molecules, known as monomers. They either occur naturally, such as DNA and proteins, or can be constructed synthetically, like plastics. They have varied structural characteristics, such as linear chains, branched chains, or complex networks, that contribute to the...
35.7K