To study the migration and diffusion phenomena of nitrates nitroglycerine(NG) and 1,2,4-butanetriol trinitrate(BTTN) as plasticizers in polyurethane elastomer under mesoscopic scale,the dissipative particle dynamics(DPD) simulation calculation was performed by molecular simulation software Materials Studio.A mesoscopic model of coarse graining was established.The diffusion coefficient of NG and BTTN in polyurethane elastomer was calculated by this model.Mesoscopic diffusion coefficient obtained by calculati...