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

3.3K
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...
3.3K
Ziegler–Natta Chain-Growth Polymerization: Overview01:17

Ziegler–Natta Chain-Growth Polymerization: Overview

4.1K
Ziegler–Natta polymerization is another form of addition or chain‐growth polymerization used for synthesizing linear polymers over branched polymers. The catalyst used for polymerization is the Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, who developed it in 1953. This catalyst is an organometallic complex of titanium tetrachloride and triethyl aluminum, with the active form of the catalyst being an alkyl titanium compound. Using the Ziegler–Natta...
4.1K
Step-Growth Polymerization: Overview01:03

Step-Growth Polymerization: Overview

4.5K
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...
4.5K
Anionic Chain-Growth Polymerization: Overview01:20

Anionic Chain-Growth Polymerization: Overview

2.7K
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,...
2.7K
Types of Step-Growth Polymers: Polyesters01:20

Types of Step-Growth Polymers: Polyesters

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

Polymer Classification: Architecture

4.0K
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...
4.0K

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

Unique Hierarchical Mesostructures Arising from Biobased Double-Crystalline PLLA-<i>b</i>-PHDO-<i>b</i>-PLLA ABA Triblock Copolymers.

Biomacromolecules·2026
Same author

Tacticity-independent crystallization of polymers.

Nature chemistry·2026
Same author

Decoupling the Roles of Chain Length, Entanglements, and Intermolecular Interactions on the Melt Memory of Semicrystalline Polar Homopolymers.

Macromolecules·2026
Same author

Crystallization-Driven Quadrant-Specific Spherulitic Self-Assembly in Partially Miscible Biodegradable PBS/PCL/PBS-<i>ran</i>-PCL Blends.

Journal of the American Chemical Society·2026
Same author

Different Crystalline Populations for Biopolyesters within Graphene-Based Nanopapers.

Macromolecules·2026
Same author

Novel Applications of Successive Self-nucleation and Annealing Thermal Fractionation for Polymer Characterization.

ACS applied polymer materials·2026
Same journal

Customizing Ionic Micelles by Dynamic Coassembly of Sequence-Defined Peptoid Block Copolymers.

Macromolecules·2026
Same journal

Investigating Polyethylene Solubility for Solvent-Based Recycling: Experiments and SAFT‑γ Mie Predictions.

Macromolecules·2026
Same journal

Molecular Dynamics Simulations of the Structural and Thermodynamic Properties of Poly(<i>l</i>‑lactic acid) in the Presence of Water.

Macromolecules·2026
Same journal

From Solvent-Mediated Micellization to Packing in a Face-Centered Cubic Structure of Poloxamers.

Macromolecules·2026
Same journal

Nonlocal Effect of Percolated Particle Networks on Viscoelasticity of Polymer-Filler Nanocomposites: A Mesoscale Simulation Study.

Macromolecules·2026
Same journal

Helicity of a confined bottlebrush ring polymer.

Macromolecules·2026
查看所有相关文章

相关实验视频

Updated: Mar 3, 2026

Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application
11:49

Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application

Published on: March 8, 2019

13.2K

自核化使热塑性聚氨中的多态选择成为可能.

Zakarya Baouch1, Leire Sangroniz2, Yunxiang Shi2

  • 1Department of Chemistry and Industrial Chemistry, University of Genoa, Via Dodecaneso 31, 16146 Genoa, Italy.

Macromolecules
|March 2, 2026
PubMed
概括
此摘要是机器生成的。

热塑性聚氨 (TPU) 的自我核化控制了晶体的形成. 这一过程加速了结晶,并有利于更有序的II形式,即使在通常无法形成它的组合中.

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

23.3K
Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
09:22

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives

Published on: February 7, 2017

8.3K

相关实验视频

Last Updated: Mar 3, 2026

Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application
11:49

Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application

Published on: March 8, 2019

13.2K
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

23.3K
Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
09:22

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives

Published on: February 7, 2017

8.3K

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:

  • 热塑性聚氨 (TPU) 具有复杂的结晶行为.
  • 在TPU中的多态性,特别是形式I和形式II,影响材料特性.
  • 控制多态结果对于定制TPU性能至关重要.

研究的目的:

  • 研究自我核化对TPU多态结晶的影响.
  • 确定自我核化如何影响结晶动力学和不同硬段 (HS) 内容的结晶结果.
  • 阐明自我核化诱导特定多态体形成的机制.

主要方法:

  • 差分扫描热量计 (DSC) 用于监测热过渡和结晶.
  • 现场广角X射线衍射 (WAXD) 用于结构分析.
  • 极化光光学显微镜 (PLOM) 用于可视化晶体形态.

主要成果:

  • 自核化显著改变TPU结晶,加速动力学并促进II形式的形成.
  • 确定了一个独特的自我核化域 (Domain II),影响了多态选择.
  • 即使是含有低HS的TPU,通常只形成I型,也被诱导通过自我核化在II型中结晶.
  • 在化物中介尿之间的键的持久性被提出为Form II偏好的原因.

结论:

  • 自核化在广泛的组成范围内对TPU多态选择提供了精确的控制.
  • 这种热处理策略使得更有序的Form II多态分子能够形成,即使在具有挑战性的组合中也是如此.
  • 自核化提供了一种多功能方法,通过受控的热处理来定制TPU材料特性.