Related Experiment Video
Updated: Aug 6, 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
Elongational flow response of associative ring polymer melts
John M Bracewell1, Dvora Perahia1,2, Gary S Grest3
1Department of Chemistry, Clemson University, Clemson, South Carolina 29634, USA. dperahia@g.clemson.edu.
Soft Matter
|July 21, 2026
Summary
Ring polymer melts with associative groups show complex flow responses. Their viscosity and density depend on both associative group interactions and the unique topology of ring structures.
Area of Science:
- Soft matter physics
- Polymer science
- Computational materials science
Background:
- Soft matter, including polymers, exhibits unique responses to flow fields.
- Associative polymers possess groups that interact, influencing their structure and dynamics.
- Ring polymers lack chain ends, introducing topological constraints absent in linear polymers.
Purpose of the Study:
- To investigate the flow response of compressible, associative ring polymer melts.
- To understand how varying the strength of associative groups affects polymer melt behavior.
- To elucidate the interplay between associative interactions and ring topology under flow.
Main Methods:
- Coarse-grained molecular dynamics simulations were employed.
- Associative ring polymers with varying interaction strengths (1 to 8 kBT) were studied.
- Simulations covered a broad range of accessible flow rates.
Main Results:
- Associative bead clusters dynamically break and reform, influencing macroscopic properties.
- Flow viscosity and density are affected by cluster dynamics and topological links.
- Ring polymer response differs from linear analogs due to topological constraints.
Conclusions:
- The macroscopic response of associative ring polymer melts is a complex function of interchain interactions and ring topology.
- Topological constraints significantly influence the flow behavior of ring polymers.
- Understanding these factors is crucial for designing and predicting soft matter behavior under flow.
Related Concept Videos
01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
01:03Step-Growth Polymerization: Overview
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...
Many natural and synthetic polymers are produced by...
01:08Molecular Weight of Step-Growth Polymers
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...
01:21Polymer 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...
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...
01:27Determination of Molar Masses of Polymers II
Polymer samples typically consist of macromolecular chains with a distribution of lengths, resulting in a range of molar masses rather than a single discrete value. Conventional descriptors such as the number-average molar mass and weight-average molar mass quantify this distribution but do not fully capture polymer behavior in solution..The viscosity-average molar mass provides a more realistic description of polymer behavior in solution because it accounts for the enhanced contribution of...
02:35Free-Radical Chain Reaction and Polymerization of Alkenes
The conversion of alkenes to macromolecules called polymers is a reaction of high commercial importance. The structure of the polymer is defined by a repeating unit, while the terminal groups are considered insignificant. The average degree of polymerization represents the number of repeating units in the polymer molecule and is denoted by the subscript n.