Related Experiment Video
Updated: Feb 19, 2026
05:48
Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes
Published on: November 21, 2017
8.6K
Indium Catalysts for Ring Opening Polymerization: Exploring the Importance of Catalyst Aggregation
Kimberly M Osten1, Parisa Mehrkhodavandi1
1Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T1Z1, Canada.
Accounts of Chemical Research
|November 1, 2017
Summary
Researchers developed new indium catalysts for biodegradable polymer production. These catalysts offer improved control and stability for ring-opening polymerization, paving the way for sustainable plastics.
Area of Science:
- Polymer Chemistry
- Materials Science
- Organic Synthesis
Background:
- Polyolefins cause environmental damage, driving demand for renewable, biodegradable alternatives.
- Biodegradable polyesters from ring-opening polymerization (ROP) of cyclic esters offer a promising solution.
- Current catalysts for lactide polymerization to poly(lactic acid) (PLA) have limitations in activity, control, and material properties.
Purpose of the Study:
- To explore indium(III) complexes as catalysts for controlled ROP of cyclic esters, particularly lactide.
- To develop novel indium-based catalysts with enhanced activity, selectivity, and stability for producing advanced biodegradable polymers.
- To investigate the influence of ligand structure and steric effects on catalyst performance and polymerization mechanisms.
Main Methods:
- Synthesis and characterization of chiral dinuclear indium complexes with tridentate diaminophenolate and tetradentate salen/salan ligands.
- Ring-opening polymerization (ROP) of lactide and other cyclic esters using indium catalysts.
- Analysis of polymerization activity, stereoselectivity, and mechanism (mononuclear vs. dinuclear propagation).
- Evaluation of catalyst stability and performance under air and in the presence of alcohols for multiblock copolymer synthesis.
Main Results:
- Developed highly active indium(III) initiators for controlled ROP of lactide and cyclic esters.
- Chiral dinuclear indium complexes with tridentate ligands showed high activity for moderately isoselective living/immortal polymerization.
- Chiral indium salen systems exhibited higher isoselectivity and mononuclear propagation.
- A novel, air- and water-stable indium salan catalyst enabled controlled synthesis of multiblock copolymers.
Conclusions:
- Indium(III) complexes are versatile and effective initiators for controlled ROP of cyclic esters.
- Ligand design, including steric and electronic factors, significantly impacts catalyst activity and stereoselectivity.
- The development of stable, air-activated indium catalysts represents a significant advancement towards industrial production of novel biodegradable polymers.
More Related Videos
Related Concept Videos
01:13Olefin Metathesis Polymerization: Overview
2.6K
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...
2.6K
01:17Ziegler–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
01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
3.2K
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...
3.2K
00:57Cationic Chain-Growth Polymerization: Mechanism
2.9K
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the...
2.9K
01:33Radical Reactivity: Intramolecular vs Intermolecular
2.2K
Radical reactions can occur either intermolecularly or intramolecularly. In an intermolecular radical reaction, a nucleophilic radical adds to an electrophilic alkene or vice versa. In such reactions, the radical and generally the alkene, which is also called the radical trap, are two different molecules. Additionally, for such intermolecular reactions to occur, the radical trap must be active, present in an excess concentration, and the radical starting material must have a weak...
2.2K
01:20Radical Reactivity: Concentration Effects
1.9K
In a radical reaction, the concentration of starting materials governs the selectivity of a radical. For example, the reaction between an alkyl halide and an alkene, in the presence of tin hydride and AIBN, begins with the generation of a tin radical. The generated radical then abstracts halogen from the alkyl halide, producing an alkyl radical. This alkyl radical can either react with tin hydride, yielding an alkane, or add to an alkene, generating a nitrile-stabilized radical, eventually...
1.9K