A synthetic rubber, developed in 1931 by the du Pont Chemical Company (based on research conducted by J.A. Nieuwland at the University of Notre Dame), produced by polymerizing acetylene to vinylacetylene, to which is added hydrochloric acid to produce chloroprene, which is then polymerized to neoprene. Neoprene is oil, chemical, and heat resistant, and has a wide variety of uses in hoses, gloves, and gaskets. It is also used in the manufacture of flexographic press rollers, offset lithographic press blankets, and squeegee blades used in screen printing, due to its excellent resistance to alcohols, Cellosolve, water, aliphatic hydrocarbons, and esters. It is not, however, resistant to aromatic hydrocarbons. Synthetic rubbers such as neoprene and Buna N have more stable physical and mechanical properties than natural rubbers.