The invention develops a preparation method of polyurethane sponge, which abandons traditional foaming processes. Instead, one-component moisture-curable polyurethane resin, water-soluble inorganic salt, starch, silicone microspheres, nonionic surfactants with an HLB value of 4‑15 and solvents are internally mixed, extruded through a die by an extruder, and then immersed in clean water to dissolve out calcium chloride (inorganic salt) and starch to obtain polyurethane sponge. Compared with conventionally prepared polyurethane sponge, the product features improved softness and water absorption capacity. It will not deform or shed residues after absorbing water up to 2.5 to 4.5 times its own weight, and presents a matte (velvet) visual effect on the surface.

Area Code: CN

Application Number: CN202010029682.4