连续激活器再生 (ICAR) 脱聚变的启动器
Glen R Jones1, Maria-Nefeli Antonopoulou1, Nghia P Truong1
1Laboratory for Polymeric Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
Journal of the American Chemical Society
|December 12, 2024
概括
持续激活剂再生 (ICAR) 脱聚变的启动剂显著降低了原子转移基聚变 (ATRP) 聚合物回收的反应温度. 这种方法在120°C实现了高单体产量,减少了能源消耗和副作用.
科学领域:
- 聚合物化学
- 可持续的化学
- 化学工程
背景情况:
- 原子转移基聚合物 (ATRP) 聚合物的化学回收需要高温 (170°C).
- 高温导致能源效率低下,由于终端组降解而降低了脱聚合产量.
- 现有的方法缺乏ATRP聚合物回收的效率和广泛适用性.
研究的目的:
- 引入持续激活器再生 (ICAR) 脱聚合剂作为ATRP聚合物的低温回收方法.
- 展示ICAR脱聚物的效率和多功能性.
- 在聚合物回收过程中减少能源消耗和副作用.
主要方法:
- 使用商业可用的自由基启动剂,以实现持续的激活剂再生.
- 在ATRP合成的聚合物中应用ICAR脱聚合.
- 通过化研究研究脱聚合效率,反应温度和副作用.
- 测试不同聚合物终端组 (,) 和催化剂 (铜,铁) 的兼容性.
主要成果:
- 在120°C达到96%的脱聚合效率,与传统方法相比显著降低.
- ICAR脱聚合转换与热可逆添加碎片链转移 (RAFT) 脱聚合可比.
- 在温和的温度下消除有害的副作用.
- 用铜和铁催化剂证明了和终结聚合物的成功脱聚合.
- 方法成功扩大到1克.
结论:
- ICAR脱聚化为ATRP聚合物的低温化学回收提供了一个广泛适用的和高效的方法.
- 这种方法通过减少能源投入和提高产量来提高可持续性.
- ICAR脱聚变是强大的,多功能,并与各种ATRP系统兼容.
相关概念视频
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
01:09Radical 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
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
01:10Radical Chain-Growth Polymerization: Overview
2.4K
Chain-growth or addition polymerization is successive addition reactions of monomers with a polymer chain. In radical chain-growth polymerization, the reaction proceeds via a free-radical intermediate. The free radical is formed from radical initiators, which spontaneously generate free radicals by homolytic fission. Organic peroxides (such as dibenzoyl peroxide, as shown in Figure 1) or azo compounds are popular radical initiators. A low concentration ratio of radical initiator to monomer is...
2.4K
02:37Restarting Stalled Replication Forks
5.7K
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart,...
5.7K
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