硬化 聚乳酸) 没有妥协 - 统计共聚化与生物衍生循环乳
Lucas A H Sanchez1, Cristian P Woroch1, David M Dumas1
1Department of Chemistry, Stanford University, 337 Campus Drive, Stanford, California 94305, United States.
Journal of the American Chemical Society
|January 28, 2025
概括
这项研究引入了一种新的生物衍生乳,即ODO,在共聚物中使用时可增强聚乳酸 (PLA) 的机械性能. 这些新材料具有更强的性和延伸性,
科学领域:
- 聚合物化学
- 材料科学
- 可持续的聚合物
背景情况:
- 聚乳酸 (PLA) 是一种可再生的聚合物,但其机械性能有限.
- 基于石油的塑料对环境造成了担忧.
- 需要具有增强性能的生物衍生替代品.
研究的目的:
- 合成和聚合一种新的生物衍生双环乳,2-oxo-3,8-dioxabicyclo[3.2.1]octane (ODO).
- 研究ODO及其同聚物与l-乳化物 (LA) 的聚合.
- 评估ODO加入对聚合物的热力学性能的影响.
主要方法:
- 通过有机催化和金属催化方法合成和聚合ODO.
- 用ODO与l-乳化物 (LA) 进行共聚.
- 同聚合物 (PODO) 和共聚物的特性,包括热和机械分析.
主要成果:
- 在溶液和融化阶段对ODO同聚合物 (PODO) 的最佳条件.
- 与e-caprolactone (CL) 相比,ODO具有更快的聚合率和更低的度.
- PODO是一种无形弹性体,其玻璃过渡温度 (Tg) 比PCL高得多.
- 与PLA相比,LA/ODO共聚物在断裂时呈现超过12倍的延长,并保持Tg,Young的模量 (E) 和屈服强度.
结论:
- 加入ODO四氨酸环可以提高乳的聚合性.
- 与原生PLA相比,基于ODO的共聚物具有更好的性和弹性.
- 这些新型生物衍生聚合物为传统塑料提供了有前途的替代品,具有卓越的机械性能.
相关概念视频
Types of Step-Growth Polymers: Polyesters
2.2K
The introduction of polyesters has brought major development to the textile industry. The wrinkle-free behavior of polyester blends has eliminated the need for starching and ironing clothes.
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the...
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the...
2.2K
Step-Growth Polymerization: Overview
3.4K
Step-growth or condensation polymerization is a stepwise reaction of bi or multifunctional monomers to form long-chain polymers. As all the monomers are reactive, most of the monomers are consumed at the early stages of the reaction to form small chains of reactive oligomers, which then combine to form long polymer chains in the late stages. Hence, the reaction has to proceed for a long time to achieve high molecular weight polymers.
Many natural and synthetic polymers are produced by...
Many natural and synthetic polymers are produced by...
3.4K
Cationic Chain-Growth Polymerization: Mechanism
2.2K
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...
2.2K
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
Anionic 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
Polymer Classification: Stereospecificity
2.4K
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
2.4K


