Raincoat for explosives: Surface chemistry approach to control wetting of nitrocellulose with nitroglycerin

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:547

Article

Grau, Henry¹  Fadeev, Alexander Y.¹ 

[1] Seton Hall Univ, Dept Chem & Biochem, S Orange, NJ 07079 USA

关键词: Wetting and contact angles;    Surface functionalization;    Silane coupling agents;    Nitrocellulose;    Nitroglycerin;    Energetic materials;   

DOI  :  10.1016/j.jcis.2019.03.063

来源: Elsevier

【 摘 要 】

Hypothesis: Wicking and percolation of a liquid in porous media is, among other factors, strongly affected by wettability of the pores. Nitrocellulose (NC) fibrous matrix impregnated with nitroglycerin (NG) is a main component of propellant formulations. Over time, NG, being a wetting liquid, leaks out from the matrix causing fires and explosions resulting from the storage. Here, we propose a chemical functionalization approach aimed at preparation of lyophobic coatings of NC to control wetting and to inhibit leakage of NG. Experimental: NC was functionalized by a two-step process using the reaction of 3-(triethoxysilyl-propyl) isocyanate followed by reactions with either alkyl-, fluoroalkyl-, or phenyl-silane producing NC surfaces ranging in lyophobicity. The wettability of the NC pellets was characterized using water, hexadecane, and NG as probe fluids. Findings: FTIR and chemical analysis supported the covalent attachment of organosilanes to NC via robust carbamate and siloxane bonds. SEM and DSC of the modified NC materials suggested that the bulk properties of NC were not affected by the reactions with silanes. The contact angles of the modified NC changed over a wide range demonstrating surfaces with tunable wetting. NC grafted with fluoroalkyl-groups showed the most NG-repelling properties (theta(Adv)/theta(Rec) similar to 90 degrees/50 degrees): NG beaded up and did not penetrate these surfaces. (C) 2019 Elsevier Inc. All rights reserved.

【 授权许可】

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