Single-component polyurethane sealant and preparation method thereof

The invention discloses a single-component polyurethane sealant and a preparation method thereof. The sealant comprises, by weight, 60-80 parts of PTMG, 30-40 parts of IPDI, 15-25 parts of 210 polyether, 3-5 parts of 204 polyether, 6-8 parts of diisononyl phthalate, 0.4-0.8 part of a water removing agent, 1.5-3.5 parts of a latent curing agent, 0.5-1.0 part of fumed silica, 40-50 parts of calciumcarbonate, 1-3 parts of barium sulfate, 0.01-0.03 part of DABCO and 0.02-0.06 part of a composite catalyst. The sealant has the advantages of high mechanical properties, immediate use after barrel opening, convenience in construction, fast curing speed, effective reduction of adverse effects of environmental factors on the construction, great reduction of the use restriction in a construction environment, and no addition of solvents in the development and production process, is an environmentally-friendly product good for the environment, meets China's current environmental protection requirements, can be directly exp