Structure and mechanical properties of crosslinked glycidyl azide polymers via click chemistry as potential binder of solid propellant

Abstract

Depending upon the advantages of high efficiency, insensitivity to humidity and so on, the reaction of azide groups in glycidyl azide polymers (GAP) with alkynyl compounds has been used as a substitute of the urethane curing strategy to develop GAP‐based binder for solid propellant. In this work, an alkynyl compound of dimethyl 2,2‐di(prop‐2‐ynyl)malonate (DDPM) reacted with GAP to produce new crosslinked materials under the catalysis of Cu(I)Cl at ambient temperature, and showed great potential as a binder in composite propellant. As the feeding molar ratio of DDPM vs. GAP increased from 1 : 1 to 5 : 1, the crosslinking densities of as‐prepared materials gradually increased, together with simultaneous enhancement of Young's modulus and tensile strength. The breaking elongation showed the maximum value of ca. 82% when the feeding molar ratio of DDPM vs. GAP was 3 : 1. In addition, with an increase of the crosslinking densities, the glass transition temperatures of as‐prepared materials significantly increased from −43.9°C to −5.1°C while the mechanical loss peaks also gradually broadened and shifted up to high temperature, and even presented two peaks at the feeding molar ratio of DDPM vs. GAP higher than 4 : 1. It indicated that the formation of triazole‐based network resulted in structural heterogeneity in the as‐prepared materials. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40636.

Structure and mechanical properties of fluorine-containing glycidyl azide polymer-based energetic binders

“…The FGAP‐based polyurethane networks gave a tensile strength of 1.5 MPa and an elongation at break of 81.6%, which represent better mechanical properties compared to pure GAP‐based polyurethane networks (tensile strength of 0.66 MPa and elongation at break of 51.1%). This may be attributable to the flexibility of main chains of FGAP being improved via copolymerization resulting in a better intermolecular reaction and mechanical behaviors of polymeric binders . Therefore, it is suggested that the synthesis of a flexible structural FGAP in the binder formulation of solid propellants can be one of the most promising solutions for overcoming the poor mechanical properties of GAP‐based solid propellants.…”

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.…”

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

“…This decrease in breaking elongation is due to the higher cross-linked density. 42 As the weight ratio of the DDPM to Acyl-GAP increases from 5 % to 15 %, more and more alkynyl groups took part in triazole linkages and this increase of crosslinking points restricts the deformation, as a result of that tensile strength increased with an expense of breaking elongation. Figure 2 shows that optimum mechanical properties achieved by using 10 % of the DDPM and beyond this ratio although the tensile strength increases but the elongation decreases dramatically due to stiffer network associated to azido side linkage.…”