Thermal conductivity of commodity polymers under high pressures

Area of Science:

• Materials Science
• Polymer Physics
• Thermodynamics

Background:

• Heat flow in polymers is critical for high-pressure applications.
• Pressure's effect on polymer thermal transport is complex and challenging to study.
• Understanding polymer architecture's role in heat transfer is essential.

Purpose of the Study:

• Investigate pressure-dependent thermal transport properties of poly(methyl methacrylate).
• Quantify the increase in thermal conductivity (κ) with pressure.
• Elucidate the microscopic mechanisms governing heat flow in polymers.

Main Methods:

• Utilized all-atom molecular dynamics simulations.
• Employed semi-analytical approaches for analysis.
• Calculated both classical and quantum-corrected thermal conductivity estimates.

Main Results:

• Thermal conductivity (κ) of poly(methyl methacrylate) increases with pressure.
• Quantum-corrected κ rises from 0.21 to 0.80 W m⁻¹ K⁻¹ from 1 atm to 10 GPa.
• Nonbonded interactions showed a sixfold increase in energy transfer rates, dominating heat flow.

Conclusions:

• Nonbonded interactions are the primary drivers of heat flow in polymers under pressure.
• Simulation results show good agreement with experimental data.
• The study provides insights into polymer thermal transport mechanisms for engineering applications.