High Modulus, Strut-like poly(ether ether ketone) Aerogels Produced from a Benign Solvent

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Poly(ether ether ketone) (PEEK) is a high-performance thermoplastic with excellent mechanical and thermal properties.
• Aerogels are highly porous materials with a wide range of applications, but their mechanical properties can be limited.
• Developing new methods for creating PEEK aerogels with improved characteristics is of significant interest.

Purpose of the Study:

• To investigate the gelation of PEEK in 1,3-diphenylacetone (DPA) and characterize the resulting aerogel morphology.
• To evaluate the physical and mechanical properties of PEEK aerogels prepared using DPA.
• To compare the properties of DPA-derived PEEK aerogels with those obtained from other solvents.

Main Methods:

• Dissolving PEEK in DPA at elevated temperatures (320 °C) followed by controlled cooling (50 °C) to induce gelation.
• Solvent exchange from DPA to water, followed by freeze-drying to prepare PEEK aerogels.
• Characterization using nitrogen adsorption, scanning electron microscopy (SEM), and X-ray scattering.

Main Results:

• A novel interconnected, strut-like morphology composed of PEEK axialites was observed for the first time in PEEK aerogels.
• PEEK aerogels exhibited densities between 0.09-0.25 g/cm³, porosities of 80-93%, and surface areas of 200-225 m²/g.
• The strut-like morphology resulted in significantly improved mechanical properties, including enhanced modulus-density scaling and load-bearing capacity compared to aerogels from other solvents.

Conclusions:

• 1,3-diphenylacetone (DPA) is a benign solvent that enables the formation of PEEK gels with a unique strut-like morphology.
• This novel morphology imparts superior mechanical robustness and load-bearing efficiency to PEEK aerogels.
• The findings present a promising pathway for developing advanced PEEK-based aerogels for demanding applications.