可再加工的聚氨泡使用乙乙烯基形成的胺
Hiba Kassem1,2, Lucie Imbernon2, Lucas Stricker1
1Polymer Chemistry Research Group, Centre of Macromolecular Chemistry (CMaC), Department of Organic and Macromolecular Chemistry, Faculty of Sciences, Ghent University, Krijgslaan 281 S4-bis, 9000 Ghent, Belgium.
ACS applied materials & interfaces
|November 2, 2023
概括
研究人员使用动态酸乙烯形成的胺基开发了可回收的聚氨泡 (PUFs). 这些可塑性PUF可以多次再加工成强的PU弹性体,为泡回收提供可持续的解决方案.
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
- 可持续化学 可持续化学
背景情况:
- 耐热聚氨泡 (PUFs) 具有永久的交叉链接,限制了它们的再加工和可回收性.
- 目前用于PUF的回收方法通常是低效和环境负担.
研究的目的:
- 在PUF骨干中引入动态单元,以提高再加工能力.
- 开发一种无溶剂的方法来生产可回收的PUF.
- 为了研究再加工的PUF的特性.
主要方法:
- 在PUF合成中将乙乙烯基形成的胺作为动态交叉链的纳入.
- 在高温 (130°C以上) 时优化泡成分的可性.
- 压缩成型PU交联材料以形成PU弹性体.
主要成果:
- 可塑性PUF在没有溶剂的情况下生产,其性能与标准PUF相似 (例如,密度为32kg/m3).
- 该材料至少可以三次压缩成型,产生强大的PU弹性体.
- 再加工的PU弹性体保持了类似的化学和热性能,玻璃过渡温度 (Tg) 在-42至-48°C之间.
结论:
- 乙乙基形成的胺使得可以制造可热再加工的PUF.
- 这种方法为回收使用终止的聚氨泡提供了一个可行的和简单的途径.
- 开发的方法解决了聚氨材料管理中的关键可持续性挑战.
相关概念视频
Preparation of Amides
3.0K
Amides are synthesized by treating carboxylic acids with amines in the presence of dehydrating agents like dicyclohexylcarbodiimide (DCC).
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent.
Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
3.0K
Amines to Amides: Acylation of Amines
2.5K
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
2.5K
Olefin 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
Amides to Carboxylic Acids: Hydrolysis
3.2K
Amides can undergo either acid-catalyzed hydrolysis or base-promoted hydrolysis through a typical nucleophilic acyl substitution. Each hydrolysis requires severe conditions.
Acid-catalyzed hydrolysis:
Hydrolysis of amides under acidic conditions yields carboxylic acids. Since the reaction occurs slowly, hydrolysis requires the conditions of heat.
The mechanism begins with the protonation of the carbonyl oxygen by the acid catalyst. The protonation makes the amide carbonyl carbon more...
Acid-catalyzed hydrolysis:
Hydrolysis of amides under acidic conditions yields carboxylic acids. Since the reaction occurs slowly, hydrolysis requires the conditions of heat.
The mechanism begins with the protonation of the carbonyl oxygen by the acid catalyst. The protonation makes the amide carbonyl carbon more...
3.2K
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
3.4K
Acetoacetic ester synthesis is a method to obtain ketones from alkyl halides and β-keto esters. The reaction occurs in the presence of an alkoxide base that abstracts the acidic proton of the β-keto esters. The step results in an enolate ion which is doubly stabilized. The enolate then reacts with an alkyl halide via the SN2 process to produce an alkylated ester intermediate with a new C–C bond. The hydrolysis of the intermediate, followed by acidification, results in an...
3.4K
Anionic 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


