but a stable competition has not yet formed.

the full name of polyurethane is polyurethane, and its english abbreviation is “pu”. it uses polyol polymer and isocyanate as raw materials, and forms a polymer material with multiple urethane segments under the action of chemical additives. it has the advantages of strong impact resistance, wide rebound range, good wear resistance and aging resistance, and is known as the fifth largest plastic after polyvinyl chloride, polystyrene,…