Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

Polymer Classification: Stereospecificity01:26

Polymer Classification: Stereospecificity

2.6K
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...
2.6K
Polymer Classification: Architecture01:14

Polymer Classification: Architecture

3.0K
Polymers are classified as linear or branched on the basis of their chain architecture. The polymer chains in linear polymers have a long chain-like structure with minimal to no branching at all. Even if a polymer features large substituent groups on the monomer, which appear as branches to the skeleton, it is not considered a branched polymer. A branched polymer contains secondary polymer chains that arise from the main polymer chain. The branching occurs when the polymer growth shifts from...
3.0K
Polymer Classification: Crystallinity01:21

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...
3.1K
Plastic Behavior01:21

Plastic Behavior

266
A material's elastic behavior is characterized by the disappearance of stress once the load is removed, allowing the material to return to its original state. However, when stress surpasses the yield point, yielding commences, marking the onset of plastic deformation or permanent set. This change from elastic to plastic behavior is influenced by the peak stress value and the duration before the load is removed. An intriguing observation occurs when a specimen is loaded, unloaded, and...
266
Types of Step-Growth Polymers: Polyesters01:20

Types of Step-Growth Polymers: Polyesters

2.3K
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...
2.3K
Molecular Weight of Step-Growth Polymers01:08

Molecular Weight of Step-Growth Polymers

2.3K
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...
2.3K

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序
Same author

Impedance-Controlled Molecular Transport Across Multilayer Skin Membranes.

Membranes·2026
Same author

Radiation-Induced Synthesis of Polymer Networks Based on Thermoresponsive Ethylene Glycol Propylene Glycol Monomers.

Gels (Basel, Switzerland)·2025
Same author

Swelling Behavior, Biocompatibility, and Controlled Delivery of Sodium-Diclofenac in New Temperature-Responsive P(OEGMA/OPGMA) Copolymeric Hydrogels.

Gels (Basel, Switzerland)·2025
Same author

Inertial Memory Effects in Molecular Transport Across Nanoporous Membranes.

Membranes·2025
Same author

Photoacoustic Characterization of TiO<sub>2</sub> Thin-Films Deposited on Silicon Substrate Using Neural Networks.

Materials (Basel, Switzerland)·2023
Same author

Data Analysis of Impaired Renal and Cardiac Function Using a Combination of Standard Classifiers.

Journal of personalized medicine·2023

相关实验视频

Updated: Sep 13, 2025

Disentangling High Strength Copolymer Aramid Fibers to Enable the Determination of Their Mechanical Properties
06:02

Disentangling High Strength Copolymer Aramid Fibers to Enable the Determination of Their Mechanical Properties

Published on: September 1, 2018

7.2K

在对比的加工条件下,同位性聚烯的结构-属性关系.

Edin Suljovrujic1, Dejan Milicevic1, Katarina Djordjevic1

  • 1Vinca Institute of Nuclear Sciences-National Institute of the Republic of Serbia, University of Belgrade, 11351 Belgrade, Serbia.

Polymers
|July 30, 2025
PubMed
概括

这项研究揭示了冷却速率如何显著改变同位性聚烯 (iPP) 的特性. 快速冷却产生灵活的iPP,而缓慢冷却产生易碎的iPP,为材料设计提供了洞察力.

关键词:
结晶化 结晶化的过程.多形态主义的多态主义.聚烯聚烯的使用方法处理条件 处理条件半晶体聚合物 半晶体聚合物

更多相关视频

Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction
11:17

Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction

Published on: January 19, 2016

22.1K
Artificial Thermal Ageing of Polyester Reinforced and Polyvinyl Chloride Coated Technical Fabric
07:48

Artificial Thermal Ageing of Polyester Reinforced and Polyvinyl Chloride Coated Technical Fabric

Published on: January 29, 2020

6.7K

相关实验视频

Last Updated: Sep 13, 2025

Disentangling High Strength Copolymer Aramid Fibers to Enable the Determination of Their Mechanical Properties
06:02

Disentangling High Strength Copolymer Aramid Fibers to Enable the Determination of Their Mechanical Properties

Published on: September 1, 2018

7.2K
Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction
11:17

Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction

Published on: January 19, 2016

22.1K
Artificial Thermal Ageing of Polyester Reinforced and Polyvinyl Chloride Coated Technical Fabric
07:48

Artificial Thermal Ageing of Polyester Reinforced and Polyvinyl Chloride Coated Technical Fabric

Published on: January 29, 2020

6.7K

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
  • 结晶的行为 结晶的行为

背景情况:

  • 隔离性聚烯 (iPP) 是一种广泛使用的合成聚合物,因其物理,热和机械性能而受到重视.
  • 半结晶聚合物的性质,如iPP是关键依赖于它们的形态学,这是由结晶条件形成的.
  • 了解加工条件对 iPP 的结构-属性关系的影响对于为特定的工业应用量身定制材料至关重要.

研究的目的:

  • 研究极端冷却条件 (快速火与非常缓慢的冷却) 对同位体聚烯 (iPP) 的形态,结构,热和机械性能的影响.
  • 探索iPP可加工性的极限,以及制备条件如何影响其最终特性.
  • 首次应用动态介电谱 (DDS) 来区分处理依赖的iPP结构形式中的分子移动性.

主要方法:

  • 在两个极端冷却条件下制备 iPP 样品:快速火 (Q 样品) 和非常缓慢的冷却 (SC 样品).
  • 使用光学显微镜 (OM),扫描电子显微镜 (SEM),广角X射线衍射 (WAXD),里埃变换红外光谱学 (FTIR),差分扫描热度计 (DSC),动态介电光谱学 (DDS) 和机械测试进行全面的表征.
  • 使用DDS分析分子移动性差异,重点关注半形态 (smectic) 和α-单临床形式.

主要成果:

  • 与冷却 (Q) 样本 (<30%晶度,≤3nm晶体) 相比,缓慢冷却 (SC) 的iPP表现出明显更高的晶度 (≥55%) 和更大的晶体 (≈20nm).
  • 机械测试显示出一个鲜明的对比:Q样本在断裂时显示>500%的延伸,而SC样本表现出易碎的行为 (在断裂时<15%的延伸).
  • DDS分析表明,SC样本中的α放松增强了强度和温度变化,这表明由于更高的晶度和更大的晶体体尺寸,结构约束更大.

结论:

  • 冷却速率是确定异性聚烯的形态和特性的一个关键因素.
  • 极端的加工条件导致具有截然不同的机械行为的独特结构形式,从高度柔性到脆性.
  • 这些发现为iPP的结构-属性-加工关系提供了关键的见解,这对于优化工业应用中的材料设计至关重要.