融化记忆效应的消失与comonomer纳入异态随机共聚体的异态随机共聚体
Leire Sangroniz1, Maryam Safari1,2, Antxon Martínez de Ilarduya3
1POLYMAT and Department of Polymers and Advanced Materials: Physics, Chemistry, and Technology, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel de Lardizábal, 3, 20018 Donostia-San Sebastián, Spain.
Macromolecules
|October 16, 2023
概括
将第二个comonomer纳入等态共聚合物中,通过破坏晶体结构和自我核的形成,显著减少了融化记忆效应. 这一发现影响了聚合物结晶研究.
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
- 结晶化 结晶化 结晶化
背景情况:
- 聚合物结晶中的融化记忆效应至关重要,但尚未完全理解,特别是关于共纳体的结合.
- 第二个共纳体对同态共聚物中自身核稳定性和融化记忆的影响在很大程度上仍未被探索.
研究的目的:
- 首次研究第二个共同体对等态随机共聚合物的融化记忆效应的影响.
- 了解如何影响融化温度,结晶性和单元细胞扭曲的共纳体含量,影响自我核稳定性和融化记忆.
主要方法:
- 研究的聚[酸丁) - 兰---) ] (PBS-ran-PCL) 随机共聚合物,以异构形态和伪学点而闻名.
- 分析了不同共纳体组合对融记忆,自我核稳定性和晶相行为的影响.
主要成果:
- 溶解记忆效应在等态共聚合物中,即使在加入1个摩尔%的共聚物中,也会大幅度降低.
- 共同分子单元破坏了晶格中的分子间相互作用,降低了自我核形成能力.
- 与基于烯酸的共聚合物不同,共聚合物单元有助于在共聚合物中达到同otropic 化状态.
结论:
- 在等态随机共聚合物中,共聚合物的结合显著减少了融记忆.
- 晶格相互作用的破坏和自我核的形成是减少融记忆背后的关键机制.
- 这项研究强调了共纳米选择及其晶相行为在定制聚合物融记忆中的关键作用.
相关概念视频
01:26Polymer Classification: Stereospecificity
2.5K
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...
2.5K
01:24Characteristics and Nomenclature of Copolymers
2.6K
Copolymers are the products obtained from the polymerization of multiple monomer species. So, in a polymer chain itself, there can be multiple repeating units that come from different monomers. The process of synthesizing a polymer from different monomer species is called copolymerization. When two monomers are involved, the polymer is known as a bipolymer. Polymers with three and four monomers are termed terpolymers and quaterpolymers, respectively. Figure 1 depicts the copolymerization of...
2.6K
01:21Polymer Classification: Crystallinity
2.9K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
2.9K
01:08Molecular Weight of Step-Growth Polymers
2.2K
Step growth polymerization involves bi or multifunctional monomers. Bifunctional monomers react to form linear step growth polymers, whereas multifunctional monomers react to form non-linear or branched polymers.
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
2.2K
01:10Polymers: Molecular Weight Distribution
3.4K
For any given polymer, the weight average molecular weight (Mw) is higher than, if not equal to, the number average molecular weight (Mn). The only situation in which the weight average molecular weight and the number average molecular weight are equal is when a polymer consists only of chains with equal molecular weight. However, this never happens in a synthetic polymer, since it is difficult to control the polymerization process up to a molecular level with accuracy to a hundred percent.
3.4K
01:13Olefin Metathesis Polymerization: Overview
2.2K
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
2.2K