Enantioselective synthesis of aziridines using asymmetric transfer hydrogenation as a precursor for chiral derivatives used as bonding agent for rocket solid propellants

Kawamoto, Aparecida M.; Wills, Martin

doi:10.1590/s0100-40422002000600007

Cited by 5 publications

(3 citation statements)

References 8 publications

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“…Concerning the possible applications for propellant, the incorporation of aziridine groups in the HTPB is remarkably interesting. The hydrogen of the aziridine groups are expected to form linkages with the perchlorate anion and therefore increase the compatibility of the ammonium perchlorate (AP) with the binder 20,28 . Amine groups is also known to react with AP ‐ many bonding agents commercially available nowadays are polyamines.…”

Section: Resultsmentioning

confidence: 99%

“…The hydrogen of the aziridine groups are expected to form linkages with the perchlorate anion and therefore increase the compatibility of the ammonium perchlorate (AP) with the binder. 20,28 Amine groups is also known to react with AP -many bonding agents commercially available nowadays are polyamines. Unlike aziridine, it produces ammonia as by product during the kneading process of the propellant, which must be purged by vacuum before adding the isocyanates.…”

Section: Infrared Evaluationmentioning

confidence: 99%

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On the functionalization and characterization of hydroxyl‐terminated polybutadiene with octyl‐1‐azide and the evaluation of polyurethane elastomers based on such modified HTPB

Lemos

Mendes

Bohn

2020

J of Applied Polymer Sci

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Hydroxyl-terminated polybutadiene (HTPB) has been modified with azidocontaining substances to be applied in propulsion systems. Pristine HTPB has compatibility issues with energetic polar substances and plasticizers, which is a drawback to develop new high-energy propellants. This work presents a path for the functionalization of HTPB, carried out through a controlled bulk reaction of it with octyl-1-azide. Then it was reacted with isophorone diisocyanate with or without dioctyl adipate (DOA). Structural, thermal, rheological, and dynamic-mechanical assessments were accomplished. Infrared revealed the arising of absorption bands associated to the C N stretching. From 13 C and 1 H nuclear magnetic resonances, it is possible to deduce the presence of amine, aziridine, and imine chemical groups, which may promote compatibilization with other polar and energetic substances. The chemical modification induced an increase of viscosity. With respect to the glass-liquid and glass-rubber transitions, the modification shifted them slightly to higher temperatures, but created stiffer networks, in agreement with the increase of polarity and chain interaction due to the presence of N-containing functionalities. Regarding the solid elastomer binder, the storage shear modulus and molecular mobility were influenced by the type of HTPB and DOA content. In general, the modified HTPB has physical properties like pristine HTPB.

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Section: Resultsmentioning

confidence: 99%

Section: Infrared Evaluationmentioning

confidence: 99%

On the functionalization and characterization of hydroxyl‐terminated polybutadiene with octyl‐1‐azide and the evaluation of polyurethane elastomers based on such modified HTPB

Lemos

Mendes

Bohn

2020

J of Applied Polymer Sci

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“…So how to do it except pre-coating? The answer is bonding agents for AP [53][54][55]! They absorb onto the AP through van der Waals force, hydrogen bond, or chemical reaction, which are provided by special functional group.…”

Section: Discussionmentioning

confidence: 99%

A Review on the Use of Burning Rate Suppressants in AP‐Based Composite Propellants

Pang²,

Wang³

et al. 2021

Propellants Explo Pyrotec

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Ammonium perchlorate (AP) is the most widely used oxidant in composite propellants. Propellants based on AP usually have a high burning rate, but in some applications, it is necessary to have a slower burning rate. The functional additives, which can reduce the burning rate of propellants, were named coolants, burning rate suppressants (BRSs), burning rate depressants, or burning rate inhibitors. This paper introduced different types of BRSs, such as amide-based compounds, cyclic azines, quaternary ammonium salts, metal salts, etc., their mechanism and development in AP-based composite propellants. For organic amines, the burning rate trend is as follows: biuret < melamine < oxamide < urea < base. Cyclic azines are special organic amines which form large, thermally stable cyclic azines in addition to common low-molecular-weight gases NH 3 , CO 2 , HCN, and N 2 O when heated. With the smallest addition but the highest effect, quaternary ammonium salts will not reduce the specific impulse of the propellant, nor do they interfere with cure reaction or adversely affect the physical properties of the cured propellant. Metal salts reduce the burning rate by forming more stable substances than HClO 4 with AP. The mechanism of BRSs is complicated, but all of them can be explained based on AP deflagration. At last, the development trend of efficient BRSs was discussed, the preparation of liquid BRSs and the combination of AP bonding agents with BRSs were both first proposed, which worth further research in the future.

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Amide, cyclohexenone, and cyclohexenone–sordaricin derivatives from the endophytic fungus Xylaria plebeja PSU-G30

et al. 2013

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Enantioselective synthesis of aziridines using asymmetric transfer hydrogenation as a precursor for chiral derivatives used as bonding agent for rocket solid propellants

Cited by 5 publications

References 8 publications

On the functionalization and characterization of hydroxyl‐terminated polybutadiene with octyl‐1‐azide and the evaluation of polyurethane elastomers based on such modified HTPB

On the functionalization and characterization of hydroxyl‐terminated polybutadiene with octyl‐1‐azide and the evaluation of polyurethane elastomers based on such modified HTPB

A Review on the Use of Burning Rate Suppressants in AP‐Based Composite Propellants

Amide, cyclohexenone, and cyclohexenone–sordaricin derivatives from the endophytic fungus Xylaria plebeja PSU-G30

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