Pressure-Driven Solid-State Radical Polymerization toward Carbon Nanothread.

Area of Science:

• Polymer Chemistry
• Materials Science
• High-Pressure Physics

Background:

• Mechanochemical radical polymerization offers solvent reduction but lacks control over polymer degradation.
• Developing controllable synthetic strategies for polymers is crucial for advanced material applications.

Purpose of the Study:

• To investigate high static pressure as a method for controlled solid-state radical polymerization.
• To synthesize novel carbon-based materials with high selectivity using a new approach.

Main Methods:

• Applying high static pressure (up to 30 GPa) to 1,3,5-trifluorobenzene.
• Analyzing the resulting polymer structure and reaction pathways using crystal structure and energy barrier calculations.

Main Results:

• 1,3,5-trifluorobenzene polymerized under high pressure, forming a selective carbon nanothread (Polymer-I polymorph).
• The polymerization proceeded via a radical 1,2-addition pathway involving the breaking of conjugated π-bonds.
• High pressure demonstrated effectiveness in initiating polymerization even for stable aromatic compounds.

Conclusions:

• High static pressure is a robust method for controlled solid-state radical polymerization.
• This technique provides precise control over polymer synthesis, overcoming limitations of traditional mechanochemical methods.
• The study offers insights into synthesizing selective polymeric carbon-based materials.