• Polymer(Korea)
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• v.30 no.2
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• pp.152-157
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• 2006

Anionic or Zwitter-ionic waterbone polyurethanes (WPU) based on mixtures of hydroxy terminated poly-butadiene and poly(propylene glycol) were prepared and their physical properties were characterized. Particle size of WPU increased with increasing the content of HTPB. It was observed that the microphase separation of soft segments and hart segments increased with increasing the content of HTPB in the WPUs. Zwitter-ionic WPU showed stronger hydrogen bonds between molecules than anionic WPU after drying. Polyurethane films obtained after drying of WPUs exhibit besmechanical properties when the HTPB content among polyols for WPUs were 25wt%. It is postulated that such mechanical properties resulted from different microphase separation of soft segments and hard segments of polyurethane films obtainec after drying of WPUs.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.504-507
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• 2017

The polybutadiene-based HTPB used as the propellant main binder influences the curing reaction rate of the binder and propellant depending on the synthetic batch. The properties of HTPB synthesized in different batches were analyzed and applied to propellants to evaluate the curing reaction rate and mechanical properties. Finally this reaction can also affect mechanical properties of propellant. And the results suggest that proper degree of curing reaction is necessary to obtain better mechanical properties of propellant.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.1
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• pp.84-90
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• 2017

It is observed that chemical characteristics of HTPB(Hydroxyl Terminated Polybutadiene) binder such as OH index, molecular weight and functionality and so on, can be different with synthetic batch, which can affect curing reaction of binder in itself or propellant. Finally this reaction can also affect mechanical properties of propellant. And the results suggest that proper degree of curing reaction is necessary to obtain better mechanical properties of propellant.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.2
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• pp.67-72
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• 2014

In this study, the viscosity of carbon black filled HTPB liner, mechanical properties and bonding force between propellant and liner were investigated. It is difficult to apply carbon black filled HTPB liner to the motor case in using a horizontal centrifugal casting because of its high viscosity. This problem is solved as a ageing premix at $60^{\circ}C$. The viscosity of premix is drastically decreased from 464 to 200 poise after 6days ageing.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.155-158
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• 2009

This study was investigated to know the thermal decomposition and measure the reaction time and temperature by EIDS cook-off test for the propellant ingredients and 2 kinds of HTPE propellants. The thermal analysis of the propellant ingredients used in this study showed that the thermal stability of these materials decreases in the following order : AP > HTPE > AN > BuNENA. In addition, propellant HTPE 002 containing AN showed that an endothermic process at around $125^{\circ}C$ corresponding to the solid`solid phase change($II{\rightarrow}I$) of AN was followed by the exothermic process due to decomposition of BuNENA/AN until $200^{\circ}C$. HTPE 001 and HTPE 001 reacted at around $250^{\circ}C$ and $152^{\circ}C$ each other, and the temperature of them sharply increased at $115^{\circ}C$ from EIDS slow cook-off tests.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.31-37
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• 2010

This study was carried out to investigate the thermal decomposition and execute EIDS slow cook-off test for the propellant ingredients and 2 kinds of HTPE propellants. The thermal analysis of the propellant ingredients used in this study showed that the thermal stability of these materials decreases in the following order : AP > HTPE > AN > BuNENA. In addition, propellant HTPE 002 containing AN showed that an endothermic process at around $125^{\circ}C$ corresponding to the solid phase change(II$\rightarrow$I) of AN was followed by the exothermic process of BuNENA/AN mixture up to $200^{\circ}C$. In EIDS slow cook-off tests, HTPE 001 and HTPE 002 reacted at around $250^{\circ}C$ and $152^{\circ}C$ respectively, and both of them showed sudden temperature increase curves at $115^{\circ}C$. The critical temperatures, $T_c$, of thermal explosion for the propellants HTPE 001 and HTPE 002, were obtained from both the non-isothermal curves at various heating rates and Semenov's thermal explosion theory. Kissinger's method that was used to calculate $T_c$ was also employed to obtain the activation energies for thermal decompositions.