Structure and mechanical properties of novel composites based on glycidyl azide polymer and propargyl‐terminated polybutadiene as potential binder of solid propellant

Abstract

Instead of the traditional isocyanate curing system as the binder of solid propellant, a triazole curing system has been developed by the reaction of azide group and alkynyl group due to a predominant advantage of avoiding to the interference of humidity. In this work, the propargyl-terminated polybutadiene (PTPB) was blended with glycidyl azide polymers (GAPs) to produce new composites under the catalysis of cuprous chloride at ambient temperature. The triazole-crosslinked network structure was regulated by changing the molar ratio of azide group in GAP versus alkynyl group in PTPB, and hence various crosslinked densities together with the composition changes of GAP versus PTPB cooperatively determined the mechanical properties of the resultant composites. Furthermore, the formed triazole-crosslinked network derived from the azide group in GAP and alkynyl group in PTPB resulted in the slight increase of glass transition temperatures and a-transition temperatures, and improved the miscibility between GAP and PTPB.

Synthesis and Characterization of [60]Fullerene-Glycidyl Azide Polymer and Its Thermal Decomposition

“…Moreover, the terminal hydroxyl group of glycidyl azide polymer (GAP) can be easily modified through various reactions such as esterification, acetalization, etherification, etc. [18][19][20][21][22][23][24]. In this paper, GAP was further functionalized via esterification with malonyl dichloride and subsequent brominate reaction to afford bromomalonic acid GAP ester (BM-GAP), which can easily react with C60 through a modified Bingel reaction [25] to afford a new fullerene derivative, namely, [60]fullerene GAP (C60-GAP), which perhaps could become a new material of energetic burning rate additive.…”

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“…Various crosslinked systems were prepared at different azide/propargyl group ratios. Triazole crosslinked network resulted in a slight increase in glass transition and -transition temperatures, reflecting the hindered rotation of polymer chain, with increasing miscibility of GAP and PTBT 37 . Dubois et al investigated the reaction between azide groups bearing polymers and double, triple bonds of the light olefins which yielded triazole and aziridine cycles.…”

Energetic interpenetrating polymer network based on orthogonal azido–alkyne click and polyurethane for potential solid propellant

“…Generally higher cross-linking density results in higher tensile strength and lower elongation at break. 33 …”

“…Mathew Instead of traditional isocyanate curing system, Chinese researcher Ding et al adopted the triazole curing system based on HTPB and GAP. 33 Blend of propargyl-terminated polybutadiene (PTPB) with GAP under the catalysis of cuprous chloride Cu (I) showed the maximum mechanical strength up to 2.5 MPa and elongation around 50 % when the molar ratios of N 3 versus C≡C was 2.0. It was a good endeavour in order to overcome the miscibility problem of the binders and compatibility issues of the high energy ingredients in the binder system.…”

“…It was a good endeavour in order to overcome the miscibility problem of the binders and compatibility issues of the high energy ingredients in the binder system. 33 1, 3-dipolar cycloaddition between azides and alkynes (Huisgen reaction) is one of the classical click reaction due to the fact that it is virtually quantitative, insensitive, very robust and orthogonal ligation reaction.…”