Burn-Rate Modifiers for Composite Propellants

The simplest way to modify the bum rate of composite propellants is by means of catalysts or ballistic modifiers. The solid catalysts that have been in use for many years can be classified into two groups. 

Metallic Oxides A number of metallic oxides have been studied to catalyze bum rate of composite propellants. The research of Jacobs et al. suggests that CuO is a 

Copper chromate -Cupric chromite -Cupric oxide 

Thus it is not copper chromate which acts directly as a catalyst but it first gets converted to CuO or Cu20 which actually catalyzes the reaction [263]. Rastogi et al. have reported that CaC03 is a better catalyst in comparison to CuO in PS/AP composite propellants [264]. 

AP is a major ingredient of composite propellants and it amounts to -70-72%. Therefore, the mechanism of increase in the burn rate of composite propellants due to the addition of catalysts or BRMs largely depends on the decomposition of AP. This has been postulated by Rastogi and his team in their publication [265] and it is briefly as follows. 

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Table 4.14 Burn-rate modifiers for composite propellants. ...

NTO is being developed in many areas these include i) a substitute for ammonium perchlorate or ammonium nitrate in solid rocket propellants, since it does not liberate undesirable products such as HC1 and has quite a high burn rate compared to ammonium perchlorate and ammonium nitrate, ii) used as a burning rate modifier for composite propellants, iii) replacing RDX and HMX in composite solid propel-... 

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