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

Polymers: Molecular Weight Distribution01:10

Polymers: Molecular Weight Distribution

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.
Polymer Classification: Architecture01:14

Polymer Classification: Architecture

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...
Polymer Classification: Crystallinity01:21

Polymer Classification: Crystallinity

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...
Polymer Classification: Stereospecificity01:26

Polymer Classification: Stereospecificity

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...
Plastic Behavior01:21

Plastic Behavior

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 reloaded.
Classification and Mechanical Properties of Synthetic Polymers01:28

Classification and Mechanical Properties of Synthetic Polymers

Synthetic polymers are classified as elastomers, fibers, or plastics based on their crystallinity. Crystallinity, the degree of long-range order in the solid state, influences the mechanical properties (stretching or contracting) of elastomers. Elastomers are flexible polymers that can expand or contract easily upon the application of an external force. They have numerous crosslinks that pull them back into their original shape when stress is removed. Silicones, for instance, are highly elastic...

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

<i>checkCIF</i> validation ALERTS: what they mean and how to respond.

Acta crystallographica. Section E, Crystallographic communications·2020
Same author

1,4-Addition of a Terminal Phosphinidene Complex to [5]Metacyclophane.

Angewandte Chemie (International ed. in English)·2018
Same author

A Structural Model for [Fe]-Only Hydrogenases.

Angewandte Chemie (International ed. in English)·2018
Same author

Controlling and tuning the dynamic nature of supramolecular polymers in aqueous solutions.

Chemical communications (Cambridge, England)·2017
Same author

Control of Electrons' Spin Eliminates Hydrogen Peroxide Formation During Water Splitting.

Journal of the American Chemical Society·2017
Same author

Directing the Self-Assembly Behaviour of Porphyrin-Based Supramolecular Systems.

Chemistry (Weinheim an der Bergstrasse, Germany)·2017

相关实验视频

Updated: Jul 16, 2026

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis
10:12

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis

Published on: July 1, 2017

在热塑性弹性体中的分子识别.

Rolf A Koevoets1, Ron M Versteegen, Huub Kooijman

  • 1Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.

Journal of the American Chemical Society
|March 3, 2005
PubMed
概括

选择性地将bisurea客体纳入热塑性弹性体取决于与尿素组距离相匹配. 这种精确的分子匹配显著改变了材料中的机械性能和染料行为.

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
  • 超分子化学 超分子化学

背景情况:

  • 热塑性弹性体 (TPE) 是具有可调整机械性能的多功能材料.
  • 比苏里亚的功能组可以形成强键,影响聚合物的自我组装和特性.
  • 控制聚合物矩阵中客分子的结合对于先进的材料设计至关重要.

研究的目的:

  • 调查 bisurea 客人被选择性地纳入 TPE 的情况.
  • 了解尿素组间距如何影响客宿主相互作用和材料特性.
  • 探索选择性结合对染料行为和机械性能的影响.

主要方法:

  • 热塑性弹性体的合成与聚四氨酸) 软块和 bisurea 硬块.
  • 用不同的甲基单元间距准备具有素功能的客人.
  • 用洗剂溶液进行可提取性测试,分析客人融入的情况.
  • 机械测试,包括延长,以评估材料性能和染料对齐性.

主要成果:

  • 只有当宿主和宿主的尿素组距离相匹配时,才观察到对bisurea客人的选择性纳入.
  • 整合显著调节了热塑性弹性体的机械性能.
  • 尿素功能化的染料显示出基于精确的尿素间距的明显提取性.

更多相关视频

Characterization of Synthetic Polymers via Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) Mass Spectrometry
06:56

Characterization of Synthetic Polymers via Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) Mass Spectrometry

Published on: June 10, 2018

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

相关实验视频

Last Updated: Jul 16, 2026

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis
10:12

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis

Published on: July 1, 2017

Characterization of Synthetic Polymers via Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) Mass Spectrometry
06:56

Characterization of Synthetic Polymers via Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) Mass Spectrometry

Published on: June 10, 2018

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

  • 弹性纤维薄膜的延长揭示了匹配与不匹配染料对齐性上的差异.

    • 结论:

    • 精确匹配尿素组间距对于选择性将客体纳入 bisurea 基 TPE 中至关重要.
    • 这种分子级别的控制提供了一个强大的策略来调整材料特性.
    • 尿素功能化的染料作为敏感探针,用于分子相互作用和对齐在弹性体矩阵内.