Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Polymers: Molecular Weight Distribution01:10

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
Polymer Classification: Architecture01:14

Polymer Classification: Architecture

2.9K
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...
2.9K
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
Polymer Classification: Stereospecificity01:26

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
Radical Chain-Growth Polymerization: Mechanism01:09

Radical Chain-Growth Polymerization: Mechanism

2.9K
The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization initiates when a free radical generated from the radical initiator adds to the unsaturated bond in the monomer. The unpaired electron of the free radical and one π electron in the unsaturated bond creates a σ bond between the free radical and the monomer. As a result, the other π electron in the unsaturated bond converts this...
2.9K
Radical Chain-Growth Polymerization: Chain Branching01:17

Radical Chain-Growth Polymerization: Chain Branching

1.8K
The skeletal structure of polymers synthesized via radical polymerization is always branched. For example, the polymerization of ethylene by radical polymerization results in a low-density grade of polyethylene with a heavily branched skeletal structure. Here, the radical site abstracts hydrogen from the growing chain, and the radical site shifts from the end (a primary carbon center) to anywhere within the growing chain (a secondary carbon center). Consequently, the part of the chain from the...
1.8K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

4H-SiC PIN Diodes as Environment to Modify <sup>7</sup>Be Radioactive Decay Time.

Materials (Basel, Switzerland)·2026
Same author

HLA profile in paediatric ITP: Comparison with healthy controls and prognostic implications.

British journal of haematology·2026
Same author

Dynamics in renewable sourced random poly(trimethylene 2,5-furanoate-<i>co</i>-trimethylene suberate) copolymers: ambient-pressure fragility and compensation law in secondary relaxations.

Physical chemistry chemical physics : PCCP·2026
Same author

On the Nature of Fluorescence Modification Induced by Deformation in Regenerated Silk Fibroin.

ACS applied bio materials·2025
Same author

Case Report: Eltrombopag in mosaic and gene therapy-treated patients with Fanconi anemia.

Frontiers in pediatrics·2025
Same author

Eltrombopag for Bone Marrow Failure in Fanconi Anemia: Results From the Phase II Clinical Trial FANCREV.

European journal of haematology·2025

Related Experiment Video

Updated: May 5, 2026

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes
09:17

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes

Published on: January 30, 2015

11.4K

Restricted dynamics in oriented semicrystalline polymers: poly(vinilydene fluoride).

Amelia Linares1, Aurora Nogales, Alejandro Sanz

  • 1Instituto de Estructura de la Materia, CSIC, C/ Serrano, 121, 28006 Madrid, Spain. alinares@iem.cfmac.csic.es

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|January 15, 2011
PubMed
Summary

Confinement effects on poly(vinylidene fluoride) (PVDF) α relaxation reveal that increased barrier height correlates with constraint heterogeneity. Oriented PVDF exhibits larger cooperative rearrangement regions, growing as temperature decreases.

More Related Videos

Synthesis of Terpolymers at Mild Temperatures Using Dynamic Sulfur Bonds in PolyS-Divinylbenzene
09:16

Synthesis of Terpolymers at Mild Temperatures Using Dynamic Sulfur Bonds in PolyS-Divinylbenzene

Published on: May 20, 2019

7.1K
Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers
08:12

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers

Published on: December 16, 2022

3.1K

Related Experiment Videos

Last Updated: May 5, 2026

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes
09:17

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes

Published on: January 30, 2015

11.4K
Synthesis of Terpolymers at Mild Temperatures Using Dynamic Sulfur Bonds in PolyS-Divinylbenzene
09:16

Synthesis of Terpolymers at Mild Temperatures Using Dynamic Sulfur Bonds in PolyS-Divinylbenzene

Published on: May 20, 2019

7.1K
Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers
08:12

Depolymerizable Olefinic Polymers Based on Fused-Ring Cyclooctene Monomers

Published on: December 16, 2022

3.1K

Area of Science:

  • Polymer Physics
  • Materials Science
  • Thermodynamics

Background:

  • Dielectric broadband spectroscopy reveals α relaxation in semicrystalline polymers.
  • Confinement effects are crucial in understanding polymer dynamics within crystalline matrices.
  • Poly(vinylidene fluoride) (PVDF) is a semicrystalline polymer with diverse applications.

Purpose of the Study:

  • To analyze the effect of crystal confinement on α relaxation in isotropic and oriented PVDF.
  • To investigate the relationship between free-energy barriers and constraint heterogeneity.
  • To explore the influence of orientation and temperature on cooperative rearrangement regions.

Main Methods:

  • Dielectric broadband spectroscopy (DBS) for analyzing α relaxation.
  • Differential scanning calorimetry (DSC) for thermal characterization.
  • Wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) for structural analysis.

Main Results:

  • The average free-energy barrier (ΔF) and its dispersion (δ(ΔF)) are of the same order in both isotropic and oriented PVDF.
  • Readjustment free energy is higher in oriented PVDF, potentially due to reduced amorphous layer thickness or altered chain orientation.
  • Cooperative rearrangement regions are larger in oriented PVDF and increase in size as temperature decreases, a phenomenon observed for the first time directly from data in confined systems.

Conclusions:

  • Crystal confinement significantly impacts α relaxation dynamics in PVDF.
  • The interplay between barrier height and constraint heterogeneity is a key factor in polymer relaxation.
  • The findings provide direct evidence for confinement-enhanced cooperativity and its temperature dependence in semicrystalline polymers.