超分子热塑性塑料具有0.5Pa·s的融化粘度
Réda Agnaou1, Mathieu Capelot, Sylvie Tencé-Girault
1Matière Molle et Chimie (UMR 7167 ESPCI-CNRS), Ecole Supérieure de Physique et Chimie Industrielles de la Ville de Paris (ESPCI ParisTech), 10 rue Vauquelin, 75005 Paris, France.
Journal of the American Chemical Society
|July 30, 2014
概括
研究人员开发了新的超分子聚合物材料,将聚合物样强度与液体样流量相结合. 这一突破为先进的材料应用提供了增强的耐用性,可加工性和可回收性.
科学领域:
- 超分子化学 超分子化学
- 聚合物科学 聚合物科学
- 材料科学 材料科学 材料科学
背景情况:
- 设计具有高温聚合物状性质和低温液体状流量的材料在超分子化学中构成了重大挑战.
- 为了实现耐用,可加工和可回收的材料,需要将这些看似对立的特性结合起来.
研究的目的:
- 探索一种创建超分子聚合物材料的新策略,这些材料在加热时表现出机械强度和类似流体的行为.
- 合成和表征具有特定目标性质的超分子聚合物,包括高压力破裂和低结粘度.
主要方法:
- 利用多重凝聚反应来构建多块聚胺架构.
- 采用流学测量来确定融的粘度.
- 进行了单轴拉伸试验,以评估机械性能,例如断裂时的应力.
主要成果:
- 成功合成了具有破裂时应力超过10MPa的超分子聚合物.
- 达到低于1Pa·s的融粘度,表明在高温下具有很好的流动性.
- 对分子尺寸分布,键强度和通过多重凝结结晶的证明控制.
结论:
- 开发的多重凝聚策略使得能够设计出具有机械强度和可加工性独特组合的高分子聚合物.
- 这些材料在需要耐用性和易于处理的应用中具有重大潜力,例如先进制造和可持续材料.
- 合成方法的灵活性可以为特定的最终用途微调材料特性.
相关概念视频
Polymer Classification: Stereospecificity
2.3K
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...
2.3K
Polymer Classification: Crystallinity
3.1K
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...
3.1K
Molecular Weight of Step-Growth Polymers
2.1K
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...
2.1K
Polymers: Molecular Weight Distribution
4.0K
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.
4.0K
Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
42.6K
Intermolecular forces are attractive forces that exist between molecules. They dictate several bulk properties, such as melting points, boiling points, and solubilities (miscibilities) of substances. Molar mass, molecular shape, and polarity affect the strength of different intermolecular forces, which influence the magnitude of physical properties across a family of molecules.
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
42.6K
Surface Tension, Capillary Action, and Viscosity
28.5K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
28.5K


