Preparation of waterborne polyurethane latex and study on its cladding of RDX

Waterborne polyurethane (WPU) latex was used to coat solid padding Hexogen (RDX) by means of latex polymerization-deposition in order to improve property of complex solid propellant (NEPE). The structure of WPU was performed by measurements of FTIR and GPC. Optimization coating condition was determined by orthogonal experiment; 1 g RDX; the ratio of quantum 10% alum to latex PU-1 is 1/4; reaction time 20 min and temperature 40°C. The characterization of RDX coated by WPU was performed by measuring SEM, XPS and mass fraction of coating layer. The results indicated that surface of RDX coated by WPU latex was covered with clear and pliable film. Coating degree R was calculated as 61.15%. Mass fraction of coating layer was determined as 1.48%. Bump sensitivity experimental results indicated that the special height h₅₀ of RDX coated by WPU was determined as 45.3 cm, which increased 19 cm than that before coating. Experiments proved that coating RDX by polymerization-depositing WPU latex can enhance the desensitization performance of RDX.