Tough, Self-Healing Polyurethane Binder Constructed Using Multilevel Hydrogen-Bonded Networks for Composite Solid...

Area of Science:

• Materials Science
• Polymer Chemistry
• Propellant Technology

Background:

• Composite solid propellants require binders with high mechanical strength and self-healing capabilities for enhanced safety.
• Existing polyurethane binders often lack sufficient mechanical integrity and self-healing efficiency at operational temperatures.

Purpose of the Study:

• To develop a novel fluorinated ureido-pyrimidinone polyurethane (FUPU) binder.
• To enhance the mechanical properties and self-healing capacity of composite solid propellants.

Main Methods:

• Functionalization of hydroxy-terminated polybutadiene-based polyurethane with ureido-pyrimidinone and fluorinated segments.
• Characterization of FUPU binder properties, including tensile strength, elongation at break, and self-healing efficiency.
• Formulation and testing of composite solid propellants using the FUPU binder.

Main Results:

• The FUPU binder demonstrated a tensile strength of 1.14 MPa, elongation at break of 1066%, and 93.5% self-healing efficiency after 8 hours at 60 °C.
• Composite solid propellants with FUPU exhibited improved mechanical properties and 78.11% self-healing efficiency.
• Fluorinated segments reduced aluminum agglomeration, increasing the burning rate by 31.6% at 3.0 MPa.

Conclusions:

• The developed FUPU binder offers a viable strategy for creating high-performance composite solid propellants.
• The FUPU binder significantly enhances mechanical strength, self-healing ability, and combustion performance.
• This research provides a pathway for designing safer and more efficient solid propellants.