Review of the Adhesively Bonded Interface in a Solid Rocket Motor

Abstract

One of the most challenging requirements in a solid rocket motor (SRM) is the integrity of the charge structure which is a multilayer adhesive joint involving the propellant, liner, and insulation. The propellant/liner/insulation interface is considered to be the weakest part of the whole structure. This interface has some of the usual features of an adhesively bonded interface, as well as its own special characteristics: the co-cured process, ingredient migration between interfaces, and complicated damage mechanisms. We give a technical and critical review of the past fifty years of existing research on many aspects of the propellant/liner/insulation interface in terms of the adhesive properties and adhesive mechanisms, ingredients migration, damage determination, and fracture analysis.To present a comprehensive outline of this interface we also clarify some remaining problems which should be addressed in the future. With significant improvements in the theoretical and experimental studies of the propellant/liner/insulation interface, the problem of integrity failure of the charge structure in SRM will be well resolved. Downloaded by [Cambridge University Library] at 07:15 14 August 2015 2

Properties of Hydroxyl‐Terminal Polybutadiene (HTPB) and Its Use as a Liner and Binder for Composite Propellants: A Review of Recent Advances

“…Due to the mismatch of different kinds of material bonded together, micro-voids, micro-cracks and, other defects are unavoidably introduced in the rocket manufacturing process. The interfaces turn out to be the weakest part of the whole structure [22,23,80,86,117,139]. Several strategies were developed to preserve the integrity of each layer and the interfaces.…”

“…Since then, still only a minor number of reports were published giving a general overview of HTPB properties [13][14][15][16] as far as our investigation has found. Other publications concentrated in particular aspects such as chemical modifications of HTPB [17,18] and its spe-cific role as binder in composite propellants [19][20][21][22], as a liner [23][24][25], and as thermal insulation [26][27][28].…”

Adhesion advances: from nanomaterials to biomimetic adhesion and applications

“…, and has no requirements on the shape of the bonding interface. It has been widely used in modern industries, including automobiles, 9 aerospace, 10 maritime, 11 construction, 12 national defense, 13 etc.…”

Influence of the Binder Structure on the Interfacial Adhesion and Antimigration Properties of the Propellant Charge

“…9,10 Although these methods can indeed improve the initial bond strength of the system, the long-term migration of plasticizers will have a serious negative impact on the bonding performance as the aging time increases. 11 The research on improving the antimigration performance is mainly focused on the modification of migrant molecules, 12−14 increasing the cross-linking density of coating materials, 3,15−17 adding antimigration fillers, 18 etc. However, there are few studies on the influence of the binder backbone structure on migration resistance.…”