Related Experiment Video
Updated: Mar 26, 2026
06:55
Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
8.5K
Density effects in entangled solutions of linear and ring polymers
1SISSA-Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy.
Summary
Linear and circular polymer chains in solutions behave differently. Rings become more compact and relax faster than linear chains, impacting solution dynamics and particle diffusion.
Area of Science:
- Polymer Physics
- Computational Chemistry
- Materials Science
Background:
- Entangled polymer solutions are crucial in materials science.
- Understanding the distinct behavior of linear versus circular (ring) polymers is key.
- Polymer chain topology significantly influences solution properties.
Purpose of the Study:
- To compare the static and dynamic properties of linear and ring polymer chains in entangled solutions.
- To investigate the effect of solution density on polymer conformations and dynamics.
- To analyze the viscoelastic properties of solutions based on polymer topology.
Main Methods:
- Utilizing molecular dynamics computer simulations.
- Analyzing polymer chain conformations and monomer contact frequencies.
- Studying chain relaxation dynamics at equilibrium.
- Observing the diffusion of colloid-like particles within the solutions.
Main Results:
- Linear polymer chains exhibit Gaussian statistics across all densities.
- Ring polymers demonstrate increased compactness with higher solution densities.
- Solution density affects monomer contact frequencies for both topologies.
- Ring polymers relax faster than linear polymers.
- Particle diffusion is significantly faster in solutions with ring polymers.
Conclusions:
- Polymer topology (linear vs. ring) fundamentally alters chain statics and dynamics in entangled solutions.
- Ring polymers show unique crumpling behavior and enhanced dynamics compared to linear chains.
- The findings have implications for designing polymer-based materials with tailored viscoelastic properties.
Related Concept Videos
01:14Polymer Classification: Architecture
4.1K
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...
4.1K
01:10Polymers: Molecular Weight Distribution
5.1K
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.
5.1K
01:08Molecular Weight of Step-Growth Polymers
3.0K
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...
3.0K
01:17Ziegler–Natta Chain-Growth Polymerization: Overview
4.2K
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...
4.2K
01:21Polymer Classification: Crystallinity
4.2K
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...
4.2K
01:17Radical Chain-Growth Polymerization: Chain Branching
2.6K
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...
2.6K