Polyurethane as well as preparation method and application thereof

The invention relates to the technical field of fabric treatment, in particular to polyurethane as well as a preparation method and application thereof. The polyurethane is prepared from the following raw materials: a hydroxyl silicone oil modified polyhydroxy compound, polyisocyanate, a chain extender and an end-capping reagent, the chain extender is a chain extender containing at least two active groups; the hydroxyl silicone oil modified polyhydroxy compound is obtained by carrying out a metal alkoxide catalytic etherification reaction on hydroxyl silicone oil and a polyhydroxy compound. A hydroxyl silicone oil modified polyhydroxy compound and a polyether silicone oil chain segment are adopted to endow the fabric with better hydrophilicity and softness, and chain extenders with different active groups are adopted to control the reaction rate of NCO and different groups, so that chain extension is carried out step by step, gel caused by too fast reaction is prevented, and meanwhile, the branching degree is