Compression-induced transformation of aldehydes into polyethers: a first-principles molecular dynamics study

Area of Science:

• Materials Science
• Physical Chemistry
• Computational Chemistry

Background:

• Acetaldehyde (MeCHO) is a common organic compound.
• Understanding its behavior under extreme conditions is crucial for various applications.
• Polymerization reactions can lead to materials with unique properties.

Purpose of the Study:

• To investigate the polymerization of acetaldehyde under increasing pressure using simulations.
• To determine the critical density required for polyether formation.
• To explore the potential of this reaction in lubrication.

Main Methods:

• First-principles molecular dynamics simulations were employed.
• Simulations were conducted at varying pressures, densities, and temperatures.
• Geometric constraints were used to study density effects.

Main Results:

• Increasing pressure leads to acetaldehyde polymerization, forming polyethers via C-O bond formation.
• Polymerization initiates only after reaching a critical density of approximately 1.7 g/cm³.
• Polyether formation is linked to significant energy dissipation, which decreases post-formation.
• The polyethers exhibit stability up to 60 GPa.

Conclusions:

• A critical density, not just pressure or temperature, drives acetaldehyde polymerization.
• The structural requirement for polymerization is a specific interatomic distance (≈2.5 Å) between carbon and oxygen atoms.
• The resulting polyethers show promise as lubricants under extreme conditions due to their stability and energy dissipation characteristics.