• Macromolecular Research
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• v.15 no.3
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• pp.225-233
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• 2007

To improve the poor mechanical and low-temperature properties of glycidyl azide polymer (GAP)-based propellants, the addition of binders was investigated using GAP and flexible polymer backbone-structural polycaprolactone (PCP) at various weight(wt) ratios, and varying the ratio of Desmodur N-100 pluriisocyanate (N-100) to isophorone diisocyanate (IPDI). Using Gee's theory, the solubility parameter of the PCP network was determined, in order to elucidate the physical and chemical interaction between GAP and PCP. The structure of the binder networks was characterized by measuring the cross-link densities and molecular weights between cross-links ($M_c$) obtained by a swelling experiment using Flory-Rhener theory. The thermal and mechanical properties of the segmented block copolyurethane (GAP-b-PCP) binders prepared by the incorporation of PCP into the binder recipes were investigated, along with the effect of the different curatives ratios.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.5
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• pp.660-666
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• 2009

Thermoplastic polyurethane elastomer(PU-TPE) and energetic thermoplastic polyurethane Elastomer(E-PU-TPE) were prepared from Hexamethylene diisocyanate(HDI), 1,4-BD/AA ester polyol and glycidyl azide polymer(GAP-2400) as an energetic material by the addition polymerization. The PU-TPE and E-PU-TPE were characterized by FT-IR and GPC. Viscometer, DSC and UTM were used to investigate the viscose behavior with a various solvent, thermal properties and mechanical properties of PU-TPE and E-PU-TPE, which are of potential interest for the development of high performance binder of energetic solid propellants. It was found that $M_w$ of PU-TPE and E-PU-TPEs are over 100,000 and decreased with increase of GAP-2400 contents. $T_m$ and ${\Delta}H$ as thermal properties decreased and also tensile strength and elongation at break as mechanical properties decreased with increase of GAP-2400 contents.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.1 s.20
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• pp.69-80
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• 2005

A synthesis of azide-terminated glycidyl azide polymer, GAP-A, was carried out by tosylation and azidation of polyepichlorohydrin(PECH) prepared by cationic ring-opening polymerization. Polyepichlorohydrin was prepared by cationic activated monomer polymerization using ethylene glycol and $BF_3{\cdot}OEt_2$ as an initiator and a catalyst at $\~10^{\circ}C$. Tosylation of polyepichlorohydrin was performed using traditional TsCl/pyridine method and was also carried out using TsCl/amine catalysts to reduce the reaction time significantly. Azidation of tosyl-terminated PECH(OTs-PECH) was performed using $NaN_3$ as an azidation reagent in DMF solvent at high temperature and was unexpectedly completed within 2 hours.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.81-87
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• 2019

In this study, synthetic methods and physical properties for a new class of glycidyl azide polymer (GAP) were investigated for energetic thermoplastic elastomers (ETPE). Four kinds of GAP copolymer polyols were synthesized by introducing nucleophiles such as azide, alkoxide and alkyl amine into poly(epichlorohydrin) (PECH). The GAP copolymer synthetic reaction can be evaluated as an environmental benign and efficient synthetic method due to the simultaneous one-step reaction using two kinds of nucleophiles and the complete consumption of sodium azide. The relative stoichiometric substitution ratio analysis and the progress of reaction were checked and monitored by inverse gated decoupled $^{13}C$ NMR and Fourier transform infrared (FT-IR) spectroscopy. The glass transition temperature and molecular weight were measured by differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) analysis. The synthesized poly($GA_{0.8}-butoxide_{0.2}$), poly($GA_{0.7}-n-butylamine_{0.3}$), poly($GA_{0.7}-dipropylamine_{0.3}$) and poly($GA_{0.7}-morpholine_{0.3}$) had a glass transition temperature ranged from -39 to $-26^{\circ}C$.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.2
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• pp.228-235
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• 2009

We synthesized glycidyl azide monomer(GAM) as a monomer for polymerization of glycidy azide polymer(GAP) which is a promising energetic prepolymer for a plastic-bonded explosive. Using quantitative real-tim in-situ infrared(in-situ IR) spectroscopy, kinetic study on the cationic ring opening polymerization of GAM was carried out. The reaction rate was obtained from monitoring the change of ether C-O stretching band($1050cm^{-1}$) in series IR spectra. The reaction was in accordance with the first-order reaction law for each of reaction temperature at 100/1 mole ratio of [GAM]/[$BF_3*etherate$]. In the ring opening polymerization of GAM, with ratio of [GAM]/[$BF_3*etherate$] to equal 100/1 at various temperature, the activation parameters obtained from the evaluation of kinetic data were ${\Delta}H^*$=14.34kcal/mol, ${\Delta}S^*=-12.31cal/mol{\cdot}K$ and $E_a$=14.89kcal/mol.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.1
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• pp.71-78
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• 2019

This paper describes the formulation and properties of a recently developed energetic thermoplastic (ETPE) propellant, which is composed of 45% of newly synthesized glycidyl azide polymer, energetic plasticizer (DEGDN) and nitramine oxidizer (RDX). Compared to conventional thermoplastic propellants, the new ETPE propellant showed approximately 7% higher performance and exhibited similar mechanical properties but a lower burn rate and a higher pressure exponent.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.3
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• pp.41-46
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• 2020

In this study, measurement and analysis results from Differential scanning calorimetry(DSC) and Thermogravimetric analysis(TGA) on the newly developed high-energy thermoplastic elastomer(ETPE) propellant are described, followed by the previous study done under the same title as this paper [1]. The characteristics of high-energy thermoplastic propellant were also verified by conducting thermal analysis, and the LSGT, Shotgun & RQ Bomb test, was carried out as well. High energetic thermoplastic binders containing 45% of GAP(Glycidyl Azide Polymer), energetic plasticizer(DEGDN) and Oxidizer Aonium Perchlorate), RDX(reseach development explosive, cyclotrimethylenetrinitramine) were used to formulate the propellant.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.305-313
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• 2013

In this study, we investigated effects of thermal annealing on the thermal properties and microphase separation behaviors of glycidyl azide-based thermoplastic polyurethane elastomers (ETPE). The GAP-based ETPEs were characterized by attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimeter (DSC), dynamic mechanical analysis (DMA), and gel permeation chromatography (GPC). The effects of annealing temperature conditions ($80{\sim}130^{\circ}C$, 1 h or 24 h) on the properties of the ETPEs were investigated. The intensity of azide group absorption peak of ATR-FTIR spectra and the solubility of ETPE for methylene chloride and dimethylformamide solvent decreased after the annealing at $130^{\circ}C$ for 1 h and at $105^{\circ}C$ for 24 h. With increasing the annealing temperature from $80^{\circ}C$ to $110^{\circ}C$, the high temperature rubbery plateau region of storage modulus curves from DMA thermogram for GAP-based ETPEs was extended to the higher temperature.

• Applied Chemistry for Engineering
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• v.31 no.3
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• pp.284-290
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• 2020

Energetic thermoplastic elastomers (ETPEs) based on glycidyl azide polymer (GAP) and carboxylated GA copolymers [GAP-ETPE and poly(GA-carboxylate)-ETPEs] were synthesized using isophorone diisocyanate (IPDI), dibutyltin dilaurate (DBTDL), 1,4-butanediol (1,4-BD), and soft segment oligomers such as GAP and poly(GA-carboxylate). The synthesized GAP-ETPE and poly(GA-carboxylate)-ETPEs were characterized by Fourier transform infrared (FT-IR), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), universal testing machine (UTM), calorimetry and sensitivity towards friction and impact. DSC and TGA results showed that the introduction of carboxylate group in GAP helped to have better thermal properties. Glass transition temperatures of poly(GA-carboxylate)-ETPEs decreased from -31 ℃ to -33 ℃ compared to that of GAP-ETPE (-29 ℃). The first thermal decomposition temperature in poly(GA_0.8-octanoate_0.2)-ETPE (242 ℃) increased in comparison to that of GAP-ETPE (227 ℃). Furthermore, from calorimetry data, poly(GA-carboxylate)-ETPEs exhibited negative formation enthalpies (-6.94 and -7.21 kJ/g) and higher heats of combustion (46713 and 46587 kJ/mol) compared to that of GAP-ETPE (42,262 kJ/mol). Overall, poly(GA-carboxylate)-ETPEs could be good candidates for a polymeric binder in solid propellant due to better energetic, mechanical and thermal properties in comparison to those of GAP-ETPE. Such properties are beneficial to application and processing of ETPE.

• Applied Chemistry for Engineering
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• v.31 no.3
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• pp.267-276
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• 2020

Poly(epichlorohydrin) copolyol series (PECH copolyols) were synthesized via cationic ring-opening copolymerization (ROCP) of oxirane-based monomers and effects of reaction temperature, solvent type, and initiator were studied. As a comonomer, two types of alkylene oxides were used, and polymerization conditions were conducted both with diethylene glycol (DEG) as an initiator in methylene chloride (MC) solvent and tripropylene glycol (TPG) in toluene solvent. In order to induce the active monomer (AM) mechanism in the ring-opening copolymerization reaction, the monomer was injected by an incremental monomer addition (IMA) method using a syringe pump, and the polymerization was performed at -5 ℃. PECH copolyol, a synthesized ephichorohydrin (ECH)-based copolyol, was converted to glycidyl azide-based energy-containing copolyol (GAP copolyol) by azadizing the ECH unit through a substitution reaction. It was confirmed that the synthesized azide copolyol had little effects on changes of the solvent and the initiator. Also, the molecular weight increased 500 after the azide reaction, thereby the GAP copolyol was polymerized as designed. As the content of the comonomer increased, both the T_g and viscosity tended to decrease due to the influence of the alkyl chain length. It is possible to fundamentally prevent CH₃N₃ amount produced in the azide reaction process, and it is expected that a large-scale process could be achievable.