聚氨粘合剂具有通过Diels-Alder键的化学分解性质
María Pilar Carbonell-Blasco1, María Alejandra Moyano1, Carlota Hernández-Fernández1
1Footwear Technology Centre, Campo Alto Campo, Elda, 03600 Alicante, Spain.
Polymers
|January 11, 2024
概括
这项研究引入了可适应的聚氨粘合剂,使用Diels-Alder化学进行可逆粘合. 这些新型粘合剂可以轻松拆卸和回收粘合材料,而不会损失性能.
科学领域:
- 聚合物科学 聚合物科学
- 材料科学 材料科学 材料科学
- 粘合技术的技术 粘合技术
背景情况:
- 传统的粘合剂依赖于不可逆转的键,限制了可重加工和可回收性.
- 共价适应网络 (CAN) 通过可逆债券提供动态化学重组.
- 迪尔斯-阿尔德 (DA) 化学提供了一种可逆的机制,用于聚氨中交联/解交联.
研究的目的:
- 使用DA化学合成和表征一种可持续的,基于溶剂的聚氨粘合剂.
- 在应用外部刺激之前和之后评估粘合剂的特性和性能.
- 证明材料的可重复加工和可回收性潜力.
主要方法:
- 聚氨预聚合物的功能化与DA二烯和二烯基.
- 使用核磁共振光谱 (NMR),布鲁克菲尔德粘度,微分扫描热量计 (DSC) 和热重力计分析 (TGA) 的表征.
- 在皮革/粘合剂/接头上进行T剥强度测试,以评估粘合性能.
主要成果:
- 通过H-NMR成功合成了DA功能化的聚氨粘合剂,并通过H-NMR确认了DA/逆DA反应.
- 功能化并没有损害耐热性,质性或粘合性.
- 粘合性能满足或超过了鞋类行业的苛刻要求.
结论:
- 开发的基于CAN的聚氨粘合剂通过可逆DA化学证明了可调节的键强度.
- 粘合剂允许在热刺激时轻松拆卸和分离结合的组件.
- 这项技术促进了材料回收和循环利用,促进了粘合剂应用的可持续性.
相关概念视频
![[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12417.jpg&w=3840&q=75)
01:16[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
10.2K
The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
10.2K
00:53Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
1.9K
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
1.9K
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
01:29Diels–Alder Reaction: Characteristics of Dienes
4.1K
The Diels–Alder reaction brings together a diene and a dienophile to form a six-membered ring. Both components have unique characteristics that influence the rate of the reaction.
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is...
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is...
4.1K
01:29Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
4.6K
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.
4.6K
02:35Free-Radical Chain Reaction and Polymerization of Alkenes
7.8K
The conversion of alkenes to macromolecules called polymers is a reaction of high commercial importance. The structure of the polymer is defined by a repeating unit, while the terminal groups are considered insignificant. The average degree of polymerization represents the number of repeating units in the polymer molecule and is denoted by the subscript n.
7.8K