Comparative study of unsaturated halo and nonhalo polyesters and inhibition of double‐base rocket propellants

Abstract

AbstractUnsaturated halo and nonhalo polyesters, based on tetrachlorophthalic anhydride, tetrabromophthalic anhydride, and phthalic anhydride with diethylene glycol and maleic anhydride, have been synthesized, using a “2‐step” polyesterification process. These were mixed with 35% styrene monomer and 0.02% hydroquinone. The structural aspects of halo and nonhalo polyesters have been studied by IR and NMR. Further, these polyesters have been characterized for various properties. A comparison of various properties suggests that tensile strength, bond strength, heat resistance, flame retardance, gel time, and oxygen index follow the order as BP‐35 > CP‐35 > NHP‐35, whereas the order for other properties, such as exotherm peak temperature, thermal conductivity, % elongation, and nitroglycerine absorption, is BP‐35 < CP‐35 < NHP‐35. Variation in the properties of cured halo and nonhalo polyesters has been discussed in terms of structural considerations. The nature of P‐t profile of inhibited double‐base (DB) rocket propellants on static evaluation suggests that CP‐35 is a potential inhibitor for DB propellants. © 1993 John Wiley & Sons, Inc.