Inhibition of Rocket Propellants

Rocket Propellant Technologists choose a propellant for any particular mission depending on the requirements. They also choose the propellant to burn in a defi- 

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Inert polymeric materials to be suitable for inhibition of rocket propellants must fulfill a number of requirements [279-281] and the important ones are given below ... 

The inhibited propellants after conditioning at ambient, cold (-40 °C) and hot (+60 °C) temperatures, should give successful performance during static evaluation. This is the most important test and even if a polymer meets all the requirements but fails in this test, it cannot be used for inhibition of rocket propellants [282]. 

The techniques generally used for inhibition of rocket propellants are sleeve technique, tape winding technique and casting technique and their salient features are as follows ... 

Inhibiting Double Base Rocket Propellants at Picatinny Arsenal. Most of the work at Pica-tinny Arsn in connection with inhibiting of solventless extruded or cast double-base propellant has been with convolute wrappings of grains or tubes with cellulose acetate. There has been a trend toward use of extruded tubes made by the casting process... 

Tris (2-ethyl hexyl) phosphate (TOP) Tricresyl phosphate (TCP) Tributyl phosphate Triethyl phosphate Flame retardant plasticizers for inhibition of DB rocket propellants... 

Novolac epoxy flexibilizers Improve low and high temperature characteristics of novolac epoxy resins for inhibition of composite rocket propellants [164]. 

It is evident from the data that the batch-to-batch variation is within the specification limits. It is, therefore, considered a better substitute of EP-4 and is likely to substitute ERDL, EP-4 for inhibition of DB and CMDB rocket propellants in future. 

Navale, P.B., Athar, J., Diwakar, R.P., Sadakale, V.G., and Agrawal, J.P. (1999) Unsaturated polyester with melamine based additives for inhibition of DB rocket propellants. Proc. Polymer 99 (Polymers Beyond AD 2000), IIT Delhi, Jan. 12-15,1999, pp. 778-781. 

Two-way analysis of variance (and higher classifications) leads to the presence of interactions. If, for example, an additive A is added to a lube oil stock to improve its resistance to oxidation and another additive, B, is added to inhibit corrosion by the stock under load or stress, it is entirely possible that the performance of the lube oil in a standard ball-and-socket wear test will be different from that expected if only one additive has present. In other words, the presence of one additive may adversely or helpfully affect the action of the other additive in modifying the properties of the lube oil. The same phenomenon is clearly evident in a composite rocket propellant where the catalyst effect on burning rate of the propellant drastically depends on the influence of fine oxidizer particles. These are termed antagonistic and synergistic effects, respectively. It is important to consider the presence of such interactions in any treatment of multiply classified data. To do this, the two-way analysis of variance table is set up as shown in Table 1.24. 

Perchlorate is concentrated by plants, especially in the leaves, that are irrigated with water-containing perchlorate. Perchlorate has been detected in vegetation and wildlife (aquatic insects, fish, frogs, mammals) near an ammunition plant historically associated with perchlorate-containing rocket propellants. There has been limited testing of perchlorate in aquatic species, soil invertebrates, and amphibians. Results in aquatic species are inconclusive because of the lack of cation controls. Perchlorate appears to inhibit thyroid activity and alter gonadal differentiation in amphibians at concentrations found in surface water. 

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