1,2,3‐triazole crosslinked polymers as binders for solid rocket propellants

Abstract

In this study, 1,2,3‐triazole crosslinked polymers were synthesized as a new binder for solid rocket propellant systems by reacting the azide groups of the polymer with the ethynyl groups of a dipolarophile curing agent. All the mixtures were cured in an oven at 52°C for 7 days, and the curing reactivity of the products was analyzed using a Fourier transform‐infrared spectrometer. The carbonyl group adjacent to the triple bond, which acts as an electron‐withdrawing group, considerably accelerated the 1,3‐dipolar cycloaddition reaction between the azide and ethynyl functional groups, affording rubbery materials. The modulus of the polymers increased whereas the elongation at the break decreased with increasing ratio of the crosslinker to the prepolymer, resulting in highly crosslinked polymers. The molecular weights between the crosslinking points and interaction parameters of the 1,2,3‐triazole crosslinked polymers were determined from the swelling data, Flory–Rehner equation, and Mooney–Rivlin equation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40594.

Hydroxyl Terminated Polybutadiene: Chemical Modification and Application of these Modifiers in Propellants and Explosives

“…However, cross-linked polyurethanes suffer from being humidity sensitivity in the curing procedure, leading to a deterioration of the mechanical properties of the propellant grains [115,116]. Additionally, this kind of curing system limits the overall energy output of the propellants due to the poor compatibility between polyurethane and highly energetic oxidizers like ammonium dinitramide (ADN) and hydrazinium nitroformate (HNF) [117][118][119]. Therefore, there is an urgent need to find a new binder methodology for high energy propellants or explosives.…”

In‐situ Robust Polymeric Networks Prepared via Facile Uncatalyzed Huisgen Cycloaddition of Alkyne‐terminated Polyurethane with Terminal Azides

“…900 g mol À1 , commercial name PCP0310) and azide-terminated PCE were synthesized as described in our previous study [17]. Trivalent terminal-alkyne compound as a crosslinker for azideterminated PCE, 1,1,1-tris(propiolyl-oxy-methyl) propane (TPMP), was synthesized as described in our earlier work [29]. Two kinds of trivalent terminal-azide compounds were synthesized as follows; Trivalent azide (1A): Methanesulfonylchloride (34.6 ml, 0.447 mol) and pyridine (36.0 ml, 0.447 mol) were added to a solution of 1,1,1-tris (hydroxymethyl) propane (10.0 g, 0.075 mol) in methylenechloride (600 ml).…”

“…However, efforts to avoid copper catalyst have focused on the development of catalyst-free (CF) AAC as an alternative to CuAAC due to the cytotoxicity of copper, especially in biological applications [19][20][21][22][23][24][25][26][27][28]. And, CF-AAC has been paid attention to the preparation of polymeric networks for solid propellants since the copper catalyst is not soluble in polymeric networks, resulting in not forming the homogeneous networks [12,15,17,18,29]. On the other hand, unlike copper catalysts, dibutyltindilaurate and triphenylbismuth mainly used in PUs are very miscible with polymers.…”

Nitramine-Group-Containing Energetic Prepolymer: Synthesis, and Its Properties as a Binder for Propellant

“…Lee et al [20] studied the properties of binders with a triazole curing system to assess their impact on the properties of the binders. Furthermore, the effects and behavior of plasticizers in the triazole-crosslinked polymer were also studied [21]. While triazole-crosslinked-polymers exhibited excellent performance characteristics, their poor cost-competitiveness by the relatively expensive raw materials required for the synthesis are the major disadvantages for their use.…”