Hypernyms (currency is a kind of...): medium of exchange; monetary system (anything that is generally accepted as a standard of value and a measure of wealth in a particular country or region). Hyponyms (each of the following is a kind of currency):money (the official currency issued by a government or national bank). Eurocurrency (currency of the major financial and industrial countries held in those countries for the purpose of lending and borrowing).edium of exchange; monetary system (anything that is generally accepted as a standard of value and a measure of wealth in a particular country or region). Hyponyms (each of the following is a kind of currency):
Polyurethane combines the best properties of rubber and plastic, without the weaknesses inherent in plasticized vinyl films. Because it contains no plasticizers, it is not subject to the brittleness and other problems caused when they leach to the surface.
What is the difference between polyurethanes and urethanes? Polyurethane coatings were invented in the mid-20th century. Plastic resins in liquid form, they are used primarily to protect wood surfaces. Their main ingredients include acids derived from vegetable oil, nitrogen-based chemical amalgams, isocyanates, and mineral spirits.