Related Experiment Video
Updated: Jun 1, 2026
05:48
Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes
Published on: November 21, 2017
Studying and Suppressing Olefin Isomerization Side Reactions During ADMET Polymerizations
Patrice A Fokou1, Michael A R Meier
1University of Applied Sciences Oldenburg/Ostfriesland/Wilhelmshaven, Constantiaplatz 4, 26723 Emden, Germany.
Macromolecular Rapid Communications
|May 19, 2011
Summary
Olefin isomerization during Ring-Opening Metathesis Polymerization (ROMP) using ruthenium catalysts can be prevented by adding benzoquinone. This allows for the creation of well-defined polymers via ADMET polymerization with minimal side reactions.
Area of Science:
- Polymer Chemistry
- Organic Synthesis
- Catalysis
Background:
- Ring-Opening Metathesis Polymerization (ROMP) is a powerful polymerization technique.
- ADMET polymerization, a type of ROMP, can suffer from olefin isomerization side reactions.
- Second-generation ruthenium metathesis catalysts are effective but can promote isomerization.
Purpose of the Study:
- To investigate and quantify olefin isomerization during ADMET polymerization.
- To identify methods for preventing olefin isomerization in ADMET polymerization.
- To enable the synthesis of well-defined polymers using ADMET with reduced side reactions.
Main Methods:
- Polyesters were synthesized using ADMET polymerization with second-generation ruthenium catalysts.
- Degradation of polyesters via transesterification with methanol yielded diesters.
- Analysis of diesters by Gas Chromatography-Mass Spectrometry (GC-MS) quantified isomerization.
Main Results:
- Quantification of olefin isomerization during ADMET polymerization was achieved.
- Addition of benzoquinone to the polymerization mixture effectively prevented olefin isomerization.
- Second-generation ruthenium catalysts can be used for ADMET with minimal isomerization when benzoquinone is present.
Conclusions:
- Olefin isomerization is a significant side reaction in ADMET polymerization with ruthenium catalysts.
- Benzoquinone acts as an effective inhibitor of olefin isomerization.
- The use of benzoquinone enables the preparation of well-defined polymers via ADMET, overcoming previous limitations.
Related Concept Videos
00:53Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
01:13Olefin Metathesis Polymerization: Overview
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
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...
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.
01:28Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
The Diels–Alder reaction is one of the robust methods for synthesizing unsaturated six-membered rings. The reaction involves a concerted cyclic movement of six π electrons: four π electrons from the diene and two π electrons from the dienophile.
01:26Polymer 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...