A novel multifunctional isocyanate curing agent, denoted as TCI, was facilely synthesized via a one-step reaction involving 1,3,5-tris(2-hydroxyethyl)cyanuric acid and hexamethylene diisocyanate. The structural design of TCI incorporates a rigid triazine ring core and three additional urethane linkages, enabling the construction of high-performance crosslinked networks within glycidyl azide polymer (GAP)-based energetic elastomers. By systematically comparing TCI with the commercially available curing agent N100, the structure–property relationships were elucidated through a combination of curing kinetics, spectroscopic characterization, mechanical testing, and thermal analysis. TCI exhibits superior reactivity toward GAP, effectively compensating for the low reactivity of secondary hydroxyl groups. Structural characterization via XRD, SAXS, and FTIR demonstrated that TCI facilitates the formation of dense and stable hydrogen-bonding networks, which reduce the intermolecular chain spacing (0.424 nm for TCI–GAP vs. 0.436 nm for N100–GAP) and optimize the microphase separation behavior of the elastomer networks.Mechanical testing demonstrated that the tensile strength and elongation at break of TCI–GAP reach 1.74 MPa and 297.7%, respectively, representing increases of 95.5% and 163% over N100–GAP (0.85 MPa and 105.8%). Morphological analysis confirmed the presence of uniformly distributed crosslinking junctions and ductile fracture features in TCI–GAP, which are responsible for the improved load-bearing capacity and energy dissipation efficiency. Dynamic hydrogen-bonding interactions were identified as the key mechanism governing the mechanical and thermal performance of TCI-GAP. DMA and LF-NMR results indicated that TCI–GAP possesses higher storage modulus and more restricted segmental motion, leading to excellent thermomechanical stability. The novel TCI curing agent offers a facile and effective approach to simultaneously improve the mechanical strength, toughness, and thermal stability of GAP-based networks, showing great promise for applications in advanced solid propellants and energetic materials.

ABSTRACT The scalable and precise synthesis of polymeric nanostructures represents a significant challenge due to the inherent trade‐off between production efficiency and morphological control. Here, we introduce a quasi ‐polymerization‐induced self‐assembly ( quasi ‐PISA) strategy that integrates in situ nucleation‐growth kinetics to fabricate uniform cylindrical micelles from liquid crystalline block copolymers at high concentrations (up to 10 wt.%). Counterintuitively, we demonstrate that the broad molecular weight distribution of PISA, often considered a drawback, can be harnessed as a key variable for precise assembly. By modulating polymerization conditions, fibril lengths were well controlled from 100 nm to over 3 µm (with length dispersity < 1.10) without requiring pre‐formed seeds. This enables the one‐pot synthesis of triblock comicelles and gram‐scale production. Rheological analysis revealed a scaling relationship between solution viscosity and fibril length ( η ∝ L 0.667 ). This work advances the scalable fabrication of length‐controlled cylindrical nanostructures, offering design principles for their practical applications in diverse fields.

Composite solid propellants face mechanical limitations due to microstructural defects in energetic binders, primarily caused by side-group steric hindrance. To address this, we propose four binder network design strategies: reactive activation, segmental densification, node reinforcement, and topological balancing. Systematically optimizing the formulation (via stoichiometric adjustments, short-chain copolyethers, multifunctional cross-linkers, and gradient curing agents) transforms the binder into a topologically dense network. This structural regulation improves the balance between strength and deformability under the present formulation design, increasing the propellant's tensile strength to 1.04 MPa and elongation at break to 44.4%. For practical structural integrity evaluation, we developed a nonlinear viscoelastic-damage coupled constitutive model based on a Prony series and interfacial debonding geometry. Implemented via a finite element user subroutine, the model reasonably captures the macroscopic mechanical response and modulus softening of the optimized propellant across a wide temperature range (-40 to 70 degrees C). This integrated approach of network regulation and constitutive modeling bridges theoretical material design with computational evaluation for actual engineering applications.

The thermal decomposition process of propellants is influenced by multiple factors, including binder structure, solid fillers type, and the interface properties between binders and solid fillers. Proper thermal decomposition behavior and thermal safety performance are crucial for the production, application and storage of propellants. The impact of binder structure on the thermal behavior of common propellant constituents is paramount for the application of binders. In this study, contact angle tests, SEM, TG and DSC were employed to investigate the influence of the structures of poly(3,3-bis(azidomethyl) oxetane-tetrahydrofuran)-energetic thermoplastic elastomers (PBT-ETPE) on the thermal decomposition process of PBT-ETPE/ammonium perchlorate (AP) composites. Multiple kinetics models and the Semenov model were utilized to analyze the impact of PBT-ETPE structure on the thermal decomposition kinetic parameters and thermal safety performance of the composites. Results indicate that the hard segment structure of PBT-ETPE exerts a direct influence on the thermal decomposition process of PBT-ETPE/AP. Binders with ordered hard domain structures demonstrate better thermal stability and higher activation energy, with a self-accelerating decomposition temperature (TSADT) of 193.48 degrees C. Binders with large but disordered hard domains exhibit enhanced interfacial performance with AP, enabling complete decomposition and high heat release, though activation energy and thermal safety properties are reduced (TSADT: 176.43 degrees C). These findings indicate that controlling the thermal properties of propellants by regulating the hard segment structures of binders is a straightforward and viable approach, facilitating their further application in military fields.

The leakage and flammability issues of composite phase change materials (CPCMs) may pose fire hazards in the case of thermal runaway. Addressing the issues, this paper leverages the reaction between hydroxyl-terminated PEG and the isocyanate groups in isophorone diisocyanate (IPDI) to form urethane bonds. These bonds restrict the free movement of molecular chains to enhance anti-leakage performance. The expanded graphite and ammonium polyphosphate are distributed in the polymer via a hot-pressing process to enhance thermal conductivity and flame retardancy. It's the first flexible-form CPCMs applied in BTMS, simultaneously demonstrating exceptional anti-leakage stability (above 99.7% of original quality in anti-leakage tests), thermal durability (the anti-leakage tests indicated a thermal cycle lifetime about sixfold longer than that of PEG), anisotropic thermal conductivity (the radial and axial thermal conductivity are about 2.61 and 3.45 W/(m·K)), highest-level flame retardancy (UL94, V0 level), and thermal runaway resistance (thermal runaway was delayed to 1653 s, a 34.3% improvement over the widely used paraffin-based CPCMs). The proposed material enhances the practical battery energy storage systems' safety, facilitating the safer and more reliable deployment of large-scale energy storage technologies.

Based on the HTPB/IPDI propellant formulation system, the compatibility of three solidifiable catalysts TPB, TEPB and TS-01 with the main component of the propellant, their respective morphological characteristics and rheological properties of the propellant slurry were analyzed by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and ARES rheometer. Combined with the curing catalytic mechanism, the influence of three curing catalysts on HTPB propellant process and mechanical properties were studied. The result show that the three curing catalysts have good compatibility with the main propellant component. TEPB and TS-01 have higher catalytic activity than TPB, which can accelerate the curing reaction process of propellant system and shorten the curing cycle of propellant. After adding TS-01, the properties of propellant were not much different from those of TPB-containing systems, and the tensile strength of propellant increased by about 0.1 MPa compared with TPB-containing propellant under the same curing conditions. Mechanical properties of TS-01-containing propellant were maintained at virtually a similar level at activity conditions of 50 degrees C, 4 days and 40 degrees C for 5 days as TPB-containing propellant at activity conditions of 60 degrees C, 8 days and 50 degrees C for 10 days.

Lithium-ion batteries are widely used in electric vehicles and portable electronic devices. However, the safety risks associated with thermal runaway (TR) remain a critical challenge, which can lead to fires or explosions. Herein, a sustainable approach to improve the battery safety has been developed a flame-retardant aerogel. This aerogel (PCA) is synthesized via a green strategy involving the construction of polyvinyl alcohol (PVA) matrix coupled with covalently bonded citric acid-polyphosphoric acid ammonium (CA-APP) network, followed by freeze-drying to form a highly porous three-dimensional structure. The PCA7.5 aerogel with 7.5% CA-APP exhibits significant improvements in mechanical and thermal properties, including a 51.6% increase in compressive modulus and the thermal conductivity as low as 0.053 W & sdot;m-1 & sdot;K-1. It also demonstrates excellent flame retardancy, achieving a limiting oxygen index (LOI) of 27.8% and UL94 V-0 rating, while effectively suppressing melt droplets and flame spread. In simulated battery TR tests, the PCA7.5 aerogel successfully isolates heat, preventing propagation to adjacent cells. Furthermore, when integrated into battery modules with phase-change material for thermal management, it can maintain battery temperatures within safe limits and improved thermal uniformity. These results contribute to the development of high-performance flame-retardant aerogels and provide valuable insights into various application. It will offer a promising pathway for improving the thermal safety performance of advanced battery technologies and other thermal management systems.

The increasing energy density of lithium-ion batteries in electric vehicles and energy-storage systems is intensifying thermal-safety challenges, particularly the risk of thermal-runaway initiation and propagation under high-rate operating conditions. To address these critical issues, in this research, we have designed a double-layer-encapsulated, modified, hydrated-salt composite phase-change material (SPHE2-UVPCM) for battery thermal management. This material, SPHE2-UV, employs sodium thiosulfate pentahydrate and sodium acetate trihydrate as the phase-change matrix, integrated within a dual-scale encapsulation architecture. Microscopically, hydrophilic fumed silica and expanded graphite collaboratively construct combine to form a porous confinement scaffold that provides nucleation sites and salt immobilization. Macroscopically, a UV-curable resin coating forms an impervious barrier to ensure mechanical integrity. Systematic characterization confirmed near-zero supercooling and enhanced thermal conductivity reaching 2.74 W m(-1) K-1 in SPHE2-UV, concurrently while simultaneously delivering a latent heat of 138.87 J g(-1) and a water-vaporization enthalpy of crystallized water measuring 509.69 J g(-1). The hierarchical encapsulation enables cyclic stability with a 96.6 % retention of latent heat after 80 cycles and with superior leak resistance, with more than 96 % of the mass retained at 150 degrees C. In battery-module testing, this composite material maintains the maximum temperature of the battery module below 50 degrees C and suppresses the temperature differential to 4.5 degrees C at a 3C discharge rate. Additionally, this research has also proven that thermal runaway can be contained effectively under simulated-abuse conditions. The unique dual-scale encapsulation architecture developed in this research thus provides a novel solution to the long-standing challenges of leakage and supercooling in hydrated-salt PCMs, while simultaneously delivering the integrated functions of thermal regulation, flame retardance, and thermal-runaway inhibition, which are key requirements for next-generation battery thermal-management systems.

This study systematically investigates the mechanical properties and establishes a constitutive model for glycidyl azide polymer-based energetic thermoplastic elastomer (GAP-ETPE). Through variable-temperature FT-IR and low-field NMR spectroscopy, we elucidate the critical role of hydrogen bonding in intermolecular-interaction-induced phase organization and its temperature-dependent dissociation, revealing a decrease in hydrogen bonding index from 60.37% to 26.86% as temperature increases from 35°C to 85°C. Uniaxial tensile tests across wide temperature (-40°C to 70°C) and strain rate (10 to 500 mm/min) ranges demonstrate significant thermo-mechanical sensitivity: maximum tensile strength (8.9 MPa) and optimal balance between strength and elongation (485.6%) occur at 0°C and low strain rates. A nonlinear four-element constitutive model incorporating entropy elasticity and segmental mobility mechanisms is developed, accurately characterizing the stress-strain response (>99% fitting accuracy in the high-elasticity region). Creep and stress relaxation analyses confirm time-dependent viscoelastic behavior, with full recovery observed under 1 MPa stress. This work provides fundamental insights into the microstructure-property relationships of GAP-ETPE and delivers a predictive framework essential for solid propellant binder design.

The block copolyether (HTPE) composed of polytetrahydrofuran and polyethylene glycol holds significant promise for preparing insensitive solid propellants. However, no corresponding photosensitive binder formulation has been available for the photopolymerization 3D printing of such propellants. In this study, a photosensitive binder formulation is developed using acrylate-terminated polyether (ATPE), obtained through end-group modification of HTPE, as the oligomer, hydroxyethyl methacrylate (HEMA) and caprolactone acrylate (CA) as reactive diluents, trimethylolpropane triacrylate (TMPTA) as the crosslinker, and N-butyl-N-(2-nitroxyethyl) nitramine (Bu-NENA) as the plasticizer. The effects of ATPE content, crosslinker content, and plasticizer ratio on mechanical properties are systematically investigated using orthogonal experimental. Based on the identified optimal levels, four distinct ATPE-HC# photosensitive binder formulations with varying ATPE contents are ultimately determined. The optimized ATPE-HC# binder films exhibit a low glass transition temperature, favorable processing characteristics, and excellent compatibility with Bu-NENA, ammonium perchlorate (AP), cyclotrimethylenetrinitramine (RDX), and aluminum powder. The results of DLP 3D printing show that ATPE-HC5# has good applicability for rapid photocuring 3D printing of solid propellants. This photosensitive binder strategy, derived from the HTPE molecular structure, not only significantly enhances the production efficiency of solid propellant but also has higher mechanical strength than the thermally cured HTPE solid propellant.

The practical application of composite phase change materials (CPCMs) is often limited by interfacial incompatibility between flame-retardant additives and phase change matrix, which accelerates material aging and degrades thermal management performance. This study presents the first demonstration that a melamine-thiocyanuric acid shell engineered on ammonium polyphosphate (MTA) significantly enhances interfacial adhesion within a polyethylene glycol-based matrix, thereby simultaneously suppressing long-term aging, preserving flame retardancy, and maintaining thermal regulation stability under operational conditions. Comprehensive characterization reveals that the MTA core shell-structured CPCMs exhibit exceptional aging resistance, retaining 99.34 % of their mass after a 40 h leakage test and showing only a 4.91 % decrease in thermal conductivity after thermal aging. The core-shell architecture further enables a gas-solid synergistic flame-retardant mechanism, allowing the material to self-extinguish within 5 s. In battery module tests, the aged MTA core shell-structured CPCMs continued to provide effective thermal management, constraining the maximum temperature to 54.24 degrees C and maintaining a temperature difference below 5.3 degrees C at a 3C discharge rate. By elucidating the critical role of interfacial compatibility in mitigating performance decay, this study not only advances the fundamental understanding of CPCM durability but also offers a scalable materials strategy for developing reliable thermal management systems in energy storage and electric vehicles.

To enhance the thermal decomposition properties of glycidyl azide polymer energetic thermoplastic elastomer (GAP-ETPE), the effects of nano-CuO supported on different carbon carriers (GO and CNT) were systematically investigated in this study. The structural characteristics and catalytic performances were comprehensively analyzed using XRD, Raman, XPS, UPS, BET, SEM, and TEM, coupled with thermal analysis techniques including TG-DSC and TG-MS. The results indicate that the catalytic performance follows the descending order of CuO/CNT > CuO/GO > CuO. Notably, CuO/CNT exhibits the optimal catalytic activity, advancing the exothermic peak temperature of the azide groups by approximately 33 °C and resulting in a more concentrated heat release process. The superior synergistic catalytic effect of CuO/CNT is attributed to the following: the three-dimensional network constructed by CNT effectively overcomes the agglomeration of CuO nanoparticles and the restacking defects typical of GO nanosheets, thereby significantly reducing the gas-solid mass transfer resistance. Simultaneously, the highly graphitized sp2 conjugated skeleton of CNT provides an exceptional electron transport capability, facilitating rapid electron migration. These findings demonstrate that the structure of carbon supports profoundly influences the synergistic catalytic effect of CuO, offering valuable insights into the design of highly efficient catalysts for energetic binders.

Aiming at the challenges of insufficient preheating-cooling integration to adapt to variable extreme environments and poor temperature uniformity in large-scale maritime power battery modules, this work proposes an integrated battery thermal management system (BTMS) based on dual-functional temperature-control plates (TCPs) and a multi-level heat flux equalization strategy. The dual-functional TCPs integrate cooling channels and heating elements via a monolithic design, enabling flexible switching between preheating and cooling modes while ensuring lightweight and compactness. The multi-level heat flux equalization strategy matches regional thermal demands: in the preheating mode, multi-level power distribution coupled with two-stage dynamic power regulation equalizes temperature distribution and raises preheating efficiency; in the cooling mode, multi-level flow rate distribution combined with rib-enhanced heat transfer structures balances heat dissipation efficiency and temperature uniformity. The results show that with the integrated BTMS, the gravimetric and volumetric energy densities of the module only decrease by 12.04% and 11.55%, respectively. The proposed preheating strategy can reduce the module temperature difference to 0.86 ℃ and shorten the preheating time to 751 s. In the cooling mode, even under 3-C high-rate discharge, the maximum temperature difference of the module is controlled within 4.19 ℃. The proposed design not only ensures excellent thermal control performance, but also balances lightweight and operating condition adaptability, providing a new solution for the thermal management system of large-scale maritime power batteries.

This study presents the preparation and characterization of an oxygen-rich photosensitive binder (ATPE-HC) based on acrylate-terminated polyether (ATPE). This binder serves as a novel matrix material for the vat photopolymerization-based 3D printing of solid propellants. Owing to its higher oxygen balance compared to conventional binders, ATPE-HC can partially replace ammonium perchlorate (AP) in propellant formulations, thereby creating space for incorporating more energetic components (e.g., CL-20, RDX). This contributes to maintaining or even enhancing the energy level. Furthermore, this binder is compatible with photopolymerization-based digital light processing (DLP) 3D printing processes, enabling not only the highresolution fabrication of complex geometries but also the good applicability for DLP 3D printing of solid propellants. It provides a new material foundation for manufacturing high-performance customized solid propellant grains.

Glycidyl azide polymer (GAP)-based polyurethane, a kind of energetic thermoplastic elastomer (ETPE), is a promising binder for advanced solid propellants, but its thermal decomposition involves overlapping competitive reactions that conventional single-step kinetic models cannot characterize accurately, limiting its engineering applications. To address this limitation, a constrained asymmetric Gaussian deconvolution strategy with fixed peak area ratios and shape constraints was developed in this work. This strategy was applied to resolve overlapping reaction rate curves converted from derivative thermogravimetric data of GAP-based ETPEs with 50 wt% GAP content at four heating rates of 5, 10, 15 and 20 K·min-1. The complex decomposition process was successfully split into five stages, assigned to azide cleavage, polyether backbone scission, carbamate cleavage, hydrocarbon product degradation and residue decomposition, with a goodness of fit of R2 > 0.998. Apparent activation energies of the five stages were determined through cross-validation by the Friedman and Flynn-Wall-Ozawa methods without prior assumption of reaction mechanisms, following the order of residue decomposition (181.4 ± 1.0 kJ·mol-1) > hydrocarbon product degradation (159.9 ± 1.0 kJ·mol-1) ≈ azide cleavage (156.5 ± 0.6 kJ·mol-1) > backbone scission (135.1 ± 0.7 kJ·mol-1) > carbamate cleavage (111.9 ± 1.1 kJ·mol-1). Pre-exponential factors with lnA0 values ranging from 22.2 to 34.0 were derived via the kinetic compensation effect. Finally, generalized master plots were employed to compare with classic solid-state reaction models for mechanistic insight, and the Šesták-Berggren model fit three major stages excellently (R2 > 0.996) by accounting for synergistic nucleation-growth and phase boundary mechanisms, enabling high-precision kinetic equations. It should be noted that the constrained deconvolution method proposed in this work has general applicability for kinetic analysis of GAP-based ETPEs with different formulations and other complex energetic polymer systems, while the obtained kinetic parameters are composition-specific and only applicable to the corresponding ETPE formulation studied herein.

Catalysts effectively enhance the thermal decomposition of Glycidyl Azide Polymer (GAP)-based composite propellants. Among these, multiwall carbon nanotube (MWCNT) exhibits significant potential due to their exceptional properties. This study systematically investigates the catalytic effect and mechanism of MWCNT on thermal decomposition of the quaternary GAP-based composite propellant and its constituents, employing thermal analysis techniques combined with first-principles simulations. Differential scanning calorimetry (DSC) and isothermal kinetic analysis demonstrate that MWCNT effectively catalyzes the decomposition of both the azido groups in GAP-based energetic thermoplastic elastomer (GAP-ETPE) and ammonium perchlorate (AP), ultimately promoting the decomposition of the propellant. Specifically: The apparent activation energy for the first-stage decomposition of azido group decreased from 189.02 kJ mol- 1 to 170.61 kJ mol- 1, the heat release from AP decomposition increased from 353.94 J g- 1 to 392.76 J g- 1, the total heat release of propellant decomposition increased from 3005.82 J g- 1 to 3274.38 J g- 1. Theoretical calculations reveal that MWCNT reduces the energy barrier of rate-limiting step during decomposition by 5.3 % for azido group and 51.2 % for AP, indicating more significant catalytic effect on AP. Electronic structure analysis of transition states demonstrates electron transfer from conjugated it-electron system of MWCNT surface to singlet nitrene and hydroxyl radical, suggesting that the catalytic ability originates from the electron-donation of MWCNT conjugated electron cloud to electron-deficient active species. This study elucidates the microscopic mechanism of MWCNT catalyzed decomposition of azido group, AP and related propellant from a theoretical perspective, providing theoretical guidance for its application in energetic materials.

Energetic materials serve as critical energy sources for weapon systems and equipment. During manufacturing and storage processes, microcracks may form in these materials, posing significant safety risks. Self-healing materials capable of autonomously repairing microstructural damage have emerged as a promising solution to mitigate such hazards. Therefore, this study focuses on the self-healing property of hydroxyl-terminated polybutadiene (HTPB), a widely utilized binder in solid propellants. We develop a self-healing adhesive film (HP-SS) by reacting isocyanate-terminated polybutadiene (IPDI-HTPB-IPDI) with two dynamic chain extenders, bis(4-hydroxyphenyl)disulfide and bis(2-aminophenyl)disulfide. The optimized HP-SS exhibits exceptional healing efficiency of 96.0%. Through systematic optimization of chain extender content, a series of adhesive films with tunable hydrogen bond density and hard segment content are prepared. The synergistic effects of disulfide metathesis and hydrogen bonding on self-healing performance are comprehensively investigated, including the influence of healing duration, temperature, and molecular mobility. This work proposes a novel strategy for regulating HTPB-based self-healing systems by balancing soft/hard segment ratios and hydrogen bond interactions, providing insights for designing high-performance energetic composites.

This study investigates the dynamic mechanical properties and molecular relaxation mechanisms of glycidyl azide polymer-based energetic thermoplastic elastomer (GAP-ETPE) through dynamic mechanical analysis (DMA). This work quantitatively revealed the relationship between the molecular motion pattern and the macroscopic performance of GAP-ETPE. Frequency-dependent DMA tests demonstrated that increased loading frequency shifts storage modulus (E ') curves toward higher temperatures, with glass transition temperature (Tg, defined by E '' peak) ranging from -36.25 degrees C to -32.71 degrees C. Exponentially Modified Gaussian (EMG) deconvolution identified three molecular motional units: Peak 1 (soft-segment relaxation), Peak 2 (imperfect hardsegment domains), and Peak 3 (ordered hard-segment microcrystals). Frequency increases drove a 20.6 % reduction in Peak1 contribution while elevating Peak 2 and Peak 3 by 16.79 % and 3.75 %, respectively, indicating hard-segment reorganization under dynamic loads. A master curve for E ' was established via timetemperature superposition (TTS), enabling prediction of viscoelastic behavior across extended frequencies (10- 3-103 Hz) with an Arrhenius-derived activation energy of 291.11 kJ & sdot;mol- 1. This work provides important insights into the dynamic mechanical properties of GAP-ETPE under complex use conditions, supporting the design of adhesives for high-energy composites.

A critical gap exists in understanding the combustion mechanism of thermoplastic hydroxyl-terminated polyether (HTPE) propellants, particularly the effects of oxidizer particle size distribution. This study innovatively demonstrates that the solid-liquid transition of HTPE binder fundamentally shifts the ignition pathway to a novel condensed-phase mechanism driven by surface reactions and liquid-phase encapsulation. By partially replacing coarse oxidizers with fine particles, we reveal their dual role: accelerating pyrolysis and enhancing condensed-phase exothermicity, while inducing non-monotonic ignition delay through competition between gas release and heat accumulation. Combustion tests show concurrent increases in burning rate and pressure exponent; with 30% fine ammonium perchlorate (AP), the burning rate rises 34.92% to 10.2 mm/s and the pressure exponent increases from 0.337 to 0.452. Furthermore, fine oxidizers significantly promote aluminum agglomeration, yielding products with d(9)(0) > 1300 mu m. A combustion model is established, elucidating the unique coupling among binder transition, oxidizer decomposition, and Al agglomeration. This research broadens and refines the mechanistic understanding of solid propellant ignition and combustion. It provides both experimental evidence and a theoretical foundation for regulating the energy-release behavior of HTPE propellants.

Hydroxyl-terminated polyether (HTPE)-based insensitive propellants exhibit unique combustion behaviors governed by their thermal stability and binder-phase dynamics. This study systematically investigates the ignition-combustion mechanisms of HTPE propellants through multi-scale characterization and modeling. Experimental results reveal that the HTPE binder forms a dynamic “liquid-phase lubricating layer” upon heating, delaying oxidizer decomposition and extending ignition delay times by an order of magnitude compared to conventional HTPB propellants. High-speed imaging and thermal analysis demonstrate that this layer modulates condensed-phase reactions, inducing cyclic Al particle agglomeration and stabilizing flame structures. The burning rate pressure index (0.337) aligns with composite propellant norms, confirming self-regulating combustion stability. A modified ignition delay model incorporating phase-change effects and a combustion framework integrating binder encapsulation dynamics further elucidate how HTPE's phase change decomposition behavior governs oxidizer gasification and flame propagation. These findings establish new insights into designing thermally stable, low-sensitivity propellants with tunable combustion performance.