Super absorbent polymer and preparation method thereof

A preparation method of a super absorbent polymer, comprising:

• heating or irradiating a monomer composition to form a hydrogel polymer by polymerization, wherein the monomer composition contains water-soluble ethylene-based unsaturated monomers and a polymerization initiator;
• drying the hydrogel polymer;
• pulverizing the dried polymer to form particles;
• and
• heating a mixture of the particles and a surface crosslinking solution at a temperature ranging from about 180 to about 200° C. to form surface crosslinked polymer particles of the super absorbent polymer,
• wherein the surface crosslinking solution contains a surface crosslinking agent and water,
• wherein the super absorbent polymer includes a water-soluble component having a ratio (dwt/d(log M)) of 0.86 or less over an entire range of molecular weight ranging from 100,000 to 300,000 when measured from an eluted solution after swelling 1 g of the super absorbent polymer in 200 ml of 0.9% NaCl solution at 25° C. for 1 hour, and
• wherein the water-soluble component is present in an amount of 5% by weight or less, based on the total weight of the super absorbent polymer, when measured from an eluted solution after swelling 1 g of the super absorbent polymer in 200 ml of 0.9% NaCl solution at 25° C. for 1 hour.