Network regulation and properties optimization of glycidyl azide polymer‐based materials as a candidate of solid propellant binder via alternating the functionality of propargyl‐terminated polyether

Abstract

A kind of glycidyl azide polymer (GAP)‐based composite has been fabricated using propargyl‐terminated ethylene oxide‐tetrahydrofuran copolymer (PPET) with two (p‐) and three (t‐) alkyne functionalities via Huisgen reaction. Independent upon the PPET functionality, both crosslink densities and mechanical properties for two GAP/PPET systems showed a positive‐interrelation changes of initial increase and subsequent decrease with an increase of azide/alkyne molar ratios. At equivalent of azide/alkyne molar ratios, the composites containing t‐PPET with higher alkyne functionality exhibited better mechanical properties, while those with two alkyne functionality presented lower glass transition. Under the regulation of alkyne functionality as 3 and azide/alkyne molar ratio as 3:1, the tensile strength, Young's modulus and breaking elongation could simultaneously reach the maximum values of 1.38 MPa, 4.07 MPa, and 122.5%, which was ascribed to optimal participation of azide/alkyne reaction into network construction. Overall, this study provides an additional optimization route for network‐structured binders in solid propellant system. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48016.

Inserting urethane into 1,2,3‐triazole click‐cured solid propellant binder to form microphase separation and enhance mechanical and combustible performances

“…The synthesis of PPET can refer to our previous work 31 . In a typical reaction, 10.0 g PET (hydroxyl content of 3.60 mmol) in 150 mL THF was added under nitrogen purging to potassium tert‐butoxide (1.62 g, 14.4 mmol) in a three‐necked flask.…”

“…The synthesis of PPET can refer to our previous work. 31 In a typical reaction, 10.0 g PET (hydroxyl content of 3.60 mmol) in 150 mL THF was added under nitrogen purging to potassium tert-butoxide (1.62 g, 14.4 mmol) in a three-necked flask. After stirring 30 min at 0 C, propargyl bromide (2.0 mL, 80 wt% in toluene, ca., 9.2 mol L À1 ) dissolved in 50 mL THF was added dropwise, and the reaction mixture was constantly stirred for another 44 h. The mixture obtained was diluted with 160 mL of 3:1 brine/water, the organic layer was washed with 80 mL of 1:1 brine/water and 130 mL brine, and dried with anhydrous magnesium sulfate.…”

Glycidyl Azide Polymer and its Derivatives-Versatile Binders for Explosives and Pyrotechnics: Tutorial Review of Recent Progress

“…Qui et al [42] fabricated GAP-based composites with propargyl-terminated ethylene oxide-co-tetrahydrofuran copolymer (PPET) exhibiting two (p-) and three (t-) alkyne functionalities via a Huisgen reaction. Changes in azide/alkylene molar ratio influence the network structures of the GAP/PPET composites, directly affecting the mechanical properties of the composites.…”

Effect of diacylhydrazine as chain extender on microphase separation and performance of energetic polyurethane elastomer

“…In the study by Zhang et al, the tensile strength of energetic polyurethane with GAP is less than 5 MPa, and the elongation at break is only 50% (18). Optimization of GAP-based polyurethane as a propellant binder is realized by modifying GAP with polycaprolactone (23), tetrahydrofuran (24), nitrocellulose filler (25) and propargyl-terminated polyether (26).…”