Plasticizer-Enabled Solvent-Free Curing of Self-Healing Binder System for Energetic Materials

Area of Science:

• Materials Science
• Polymer Chemistry
• Energetic Materials

Background:

• Solvent processing of self-healing binders for energetic materials limits reliability and energy density.
• Developing solvent-free fabrication routes is crucial for advancing energetic material performance.

Purpose of the Study:

• To establish a solvent-free curing route for Diels-Alder self-healing polybutadiene binders.
• To investigate the role of dibutyl phthalate (DBP) as a functional plasticizer and dispersant.
• To demonstrate the application of this binder system in fabricating self-healing solid propellants.

Main Methods:

• Utilized a furanyl-terminated polybutadiene binder with dibutyl phthalate (DBP) as an external plasticizer.
• Employed a solvent-free curing process to achieve crosslinked network formation.
• Fabricated a solid propellant with 80 wt% solid content using the developed binder system.

Main Results:

• The DBP-plasticized binder film exhibited self-healing of pre-cut cracks within 5 minutes at 120 °C.
• Mechanical properties were nearly fully recovered after 24 hours at 60 °C.
• Solvent-free cast solid propellant grains were dense, void-free, and healed surface cracks rapidly.

Conclusions:

• A functional plasticizer, DBP, enables solvent-free curing of self-healing polybutadiene binders.
• This method overcomes solvent-based processing limitations for energetic materials.
• The developed binder system offers a viable route for fabricating reliable, self-healing energetic materials and propellants.