Effects of Polymers on Phase Transition of ε-CL-20 and CL-20-Based PBXs

The powder X-ray diffraction technique is applied to investigate phase transitions of ε-CL-20 coated with additives (polymers and wax) and of ε-CL-20 heated in petroleum ester at different temperature points. First, CL-20-based plastic-bonded explosives (PBXs) were prepared by mechanical kneading. Characteristics of different polymer binders were measured and the relationship between polymer properties and sensitivity of CL-20-based PBXs was analyzed. The results indicated that ε-CL-20 coated with or without additives both showed high stability in the crystal phases at different temperature in petroleum ether. Compared with thermal conductivity, friction efficient and specific heat capacity, hardness of polymers has the most dominant effect on the sensitivity of CL-20-based PBXs. Butadiene rubber (BR) showed the best desensitizing effect among the chosen binders. Combination of EPDM and other several polymers (C-EPDM) as the polymer binder has higher press density and a lower expansion rate.