An Evaluation of Ethylene-Vinyl Acetate Copolymers as Desensitizers for RDX in Insensitive Booster Compositions Prepared by the Slurry Coating Technique
MATERIALS RESEARCH LABS ASCOT VALE (AUSTRALIA)
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Twelve ethylene-vinyl acetate EVA copolymers with vinyl acetate contents ranging from 12 to 51 have been evaluated as desensitizers for RDX, for production of insensitive booster compositions. The RDXEVA compositions were prepared by a solvent-slurry coating process, in which a solution of the EVA copolymer in a suitable solvent is added to an aqueous suspension of RDX, the solvent then being removed by distillation to effect coating of the polymer on the RDX. The efficiency with which the EVA copolymers coat the RDX crystal surfaces increases with increasing vinyl acetate content, and can be altered by the use of surfactants. The RDXEVA compositions all have excellent thermal stability, as assessed by the vacuum thermal stability test. The shock sensitivities of compositions prepared with copolymers containing 28 to 51 vinyl acetate were found to be between those of tetryl and PBXW-7, with the shock sensitivity generally decreasing with increasing vinyl acetate content. In general, the EVA coatings gave little desensitization to impact or cookoff only one composition had a figure of insensitiveness F of I which meets current impact sensitiveness requirements for booster explosives for fuzes, and only two compositions gave mild reactions in small-scale cookoff tests.
- Industrial Chemistry and Chemical Processing
- Ammunition and Explosives