A Polymer-Modified LLM-105 with Delayed Decomposition Onset and Fast Conversion.

Area of Science:

• Energetic Materials Science
• Computational Chemistry
• Materials Engineering

Background:

• Thermolysis of energetic materials like LLM-105 is critical for safety and performance.
• Understanding interfacial effects on decomposition mechanisms is key to material design.
• Current methods lack integrated computational and experimental approaches to study these interfaces.

Purpose of the Study:

• To investigate how interfacial constraint, via energetic polymer additives, affects LLM-105 thermolysis.
• To elucidate the coupled early- and late-stage decomposition mechanisms.
• To develop a computation-guided framework for analyzing energetic material behavior.

Main Methods:

• Reactive molecular dynamics (MD) simulations were combined with thermogravimetry-differential scanning calorimetry-Fourier transform infrared spectroscopy (TG-DSC-FTIR).
• Triaminoguanidine-glyoxal energetic polymer (TAGP) sheets were introduced between LLM-105 crystallites.
• Decomposition onset, gas evolution (NO2, N2, H2O, CO2, CO), and reaction pathways were analyzed.

Main Results:

• TAGP addition measurably modulated LLM-105 decomposition behavior.
• A delayed decomposition onset and suppressed early NO2 release were observed, with minimum NO2 at ~2.24 wt % TAGP.
• TAGP modification shifted the reaction network towards safer products (higher N2, H2O, CO2; lower CO) via strengthened NO(x) reduction and CO oxidation.

Conclusions:

• Interfacial engineering with TAGP is an effective strategy to enhance the safety of insensitive high-energy materials.
• Early pyrolysis of TAGP provides hydrogen donors and radicals that regulate interfacial chemistry.
• A small TAGP loading (2.24 wt %) improves safety by delaying decomposition and promoting N2/H2O-rich decomposition products.