使用基和基,轻松去聚合热稳定的聚乙硫和聚乙基
Yasunori Minami1,2,3, Rena Honobe1, Shunsuke Tsuyuki1
1Interdisciplinary Research Center for Catalytic Chemistry (IRC3), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
ChemSusChem
|September 20, 2024
概括
这项研究展示了一种用于化学回收超级工程塑料,如PEEK和PEES的新方法. 使用化和特殊溶剂,这些塑料可以被分解成它们的原始构件.
科学领域:
- 聚合物化学 聚合物化学
- 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:
- 超级工程塑料,如聚乙基 (PEEK) 和聚乙硫 (PEES),由于其坚固的乙烯结构,具有出色的热和化学稳定性.
- 这种固有的稳定性使得传统的化学回收具有挑战性,需要精确切切割这些强大的纽带的方法.
研究的目的:
- 为PEEK和PEES开发一种有效的化学回收方法.
- 为了证明这些聚合物的脱聚合成有价值的单体产品.
主要方法:
- 使用基和氧化去聚合PEES和PEEK.
- 反应是在150°C的1,3-二甲基-2-二胺达丁 (DMI) 溶剂中进行的.
- 调查DMI在增强基乙烯键裂解反应性的作用.
主要成果:
- 已经成功地实现了PEEK和PEES的脱聚合.
- 获得了具有4 - 基基组的单体产品 - - 二硫和二.
- 确定DMI溶剂对于促进稳定的乙烯键裂变至关重要.
结论:
- 已经建立了一种新有效的PEEK和PEES化学回收方法.
- 在DMI溶剂中使用氨酸可使这些高性能聚合物的高效脱聚合.
- 这种方法为从塑料垃圾中回收有价值的单体提供了一条途径,促进循环经济.
相关概念视频
Autoxidation of Ethers to Peroxides and Hydroperoxides
7.4K
Ethers represent a class of chemical compounds that become more dangerous with prolonged storage because they tend to form explosive peroxides when standing in the air. Autoxidation is the spontaneous oxidation of a compound in air. In the presence of oxygen, ethers slowly oxidize to form hydroperoxides and dialkyl peroxides.
7.4K
Preparation of Epoxides
7.5K
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...
7.5K
Esters to Carboxylic Acids: Saponification
4.4K
Esters can be hydrolyzed to carboxylic acids under acidic or basic conditions. Base-promoted hydrolysis of esters is a nucleophilic acyl substitution reaction in which esters react with an aqueous base, followed by an acid to give carboxylic acids. This reaction is also known as saponification because it forms the basis for making soaps from fats.
The reaction requires a base in stoichiometric amounts, which participates in the reaction and is not regenerated later. So, the base acts as a...
The reaction requires a base in stoichiometric amounts, which participates in the reaction and is not regenerated later. So, the base acts as a...
4.4K
Acid-Catalyzed Dehydration of Alcohols to Alkenes
19.3K
In a dehydration reaction, a hydroxyl group in an alcohol is eliminated along with the hydrogen from an adjacent carbon. Here, the products are an alkene and a molecule of water. Dehydration of alcohols is generally achieved by heating in the presence of an acid catalyst. While the dehydration of primary alcohols requires high temperatures and acid concentrations, secondary and tertiary alcohols can lose a water molecule under relatively mild conditions.
19.3K
Oxidation of Phenols to Quinones
2.9K
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
2.9K
Hydrolysis of Chlorobenzene to Phenol: Dow Process
2.7K
Simple aryl halides do not react with nucleophiles under normal conditions. However, the reaction can proceed under drastic conditions involving high temperatures and high pressure to give the substituted products. For example, chlorobenzene is converted to phenol using aqueous sodium hydroxide at 350 °C under high pressure by the Dow process. The reaction follows an elimination-addition mechanism involving a benzyne intermediate. Here, the chloride ion is...
2.7K


