Curing Behaviors of Alkynyl-Terminated Copolyether with Glycidyl Azide Polymer in Energetic Plasticizers

Abstract

Alkynyl-terminated polyethylene oxide−tetrahydrofuran (ATPET) and glycidyl azide polymer (GAP) could be linked through click-chemistry between the alkynyl and azide, and the product may serve a binder for solid propellants. The effects of the energetic plasticizers A3 [1:1 mixture of bis-(2,2-dinitropropy) acetal (BDNPA) and bis-(2,2-dinitropropyl) formal(BDNPN)] and Bu-NENA [N-butyl-N-(2nitroxyethyl) nitramine] on the curing reaction between ATPET and GAP have been studied. A diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY-NMR) approach has been used to monitor the change in the diffusion coefficient of cross-linked polytriazole polyethylene oxide−tetrahydrofuran (PTPET). The change in the diffusion coefficient of PTPET with A3 plasticizer is significantly higher than that of PTPET with Bu-NENA. Viscosity analysis further highlighted the difference between A3 and Bu-NENA in the curing process—the curing curve of PTPET (A3) with time can be divided into two stages, with an inflection point being observed on the fourth day. For PTPET (Bu-NENA), in contrast, only one stage is seen. The above methods, together with gel permeation chromatography (GPC) analysis, revealed distinct effects of A3 and Bu-NENA on the curing process of PTPET. X-ray Photoelectron Spectroscopy (XPS) analysis showed that Bu-NENA has little effect on the valence oxidation of copper in the catalyst. Thermogravimetric (TG) analysis indicated that Bu-NENA helps to improve the thermal stability of the catalyst. After analysis of several possible factors by means of XPS, modeling with Material Studio and TG, the formation of molecular cages between Bu-NENA and copper is considered to be the reason for the above differences. In this article, GAP (Mn = 4000 g/mol) was used to replace GAP (Mn = 427 g/mol) to successfully synthesize the PTPET elastomer with Bu-NENA plasticizer. Mechanical data measured for the PTPET (Bu-NENA) sample included ε = 34.26 ± 2.98%, and σ = 0.198 ± 0.015 MPa.

Towards Investigating the Effect of Ammonium Nitrate on the Characteristics and Thermal Decomposition Behavior of Energetic Double Base NC/DEGDN Composite

“…In addition, the absorption band, located at 1114 cm −1 , was assigned to the overlapped vibration of C-O-C [28]. The other bands associated with NC and/or DEGDN were comparable to those mentioned in previous works [19,29,30]. Additional peaks that could be observed when AN was introduced to the NC-DEGDN formulation were related to the characteristic functional groups of this oxidizer.…”

Synthesis and Characterization of Fluorodinitrobenzenes with Tunable Melting Point: Potential Low Sensitive Energetic Plasticizer and Melt‐Cast Carrier†

“…Some alternative energetic plasticizers based on nitroxyalkyl‐, azidoalkyl‐, or N ‐substituted nitro‐ based heterocycles were prepared, while the concerns towards the stability and safety issues still exist. [ 17‐20 ]…”

Synthesis and Characterization of a Novel Aqueous Glycidyl Azide Polymer Emulsion

“…It has obvious advantages such as positive heat formation, high density, low mechanical sensitivity, and so on . Thus, it has good application prospects. − The most intensive application of the GAP, as shown in the current study, is to replace the traditional inert adhesive with GAP-based energetic elastomer adhesive from the reaction of the GAP with isocyanate or click reaction. , Ampleman et al . synthesized a series of GAP-based thermoplastic energetic elastomers by using different molecular weights of the GAP and different chain extenders.…”

“…2−4 The most intensive application of the GAP, as shown in the current study, is to replace the traditional inert adhesive with GAP-based energetic elastomer adhesive from the reaction of the GAP with isocyanate or click reaction. 5,6 Ampleman et al 7 ent molecular weights of the GAP and different chain extenders. Thereafter, based on the synthesis of GAP-based elastomers, Liu 8 studied the effect of the catalyst, the addition method of the chain extenders, and the synthesis process on the performance of the elastomer.…”