Chloroprene Synthetic Rubber (Sovprene)

Abstract

Abstract 1. A method is described for the continuous polymerization of acetylene at low temperatures in a dilute aqueous solution of the catalyst, CuCl.NH4Cl. Monovinylacetylene is obtained as the chief product of the reaction, with a 75–80 per cent yield, based on the acetylene entering into the reaction, and 25–30 per cent of trimers and higher polymers of acetylene as by-products. The conversion of acetylene by a single passage of the gas is 40 per cent. The yield, based on the acetylene, is nearly 100 per cent. 2. Data on the optimum amount of the catalyst are compiled, and the principal factors which affect the process of polymerization of acetylene with the formation of monovinylacetylene as the chief product are shown. 3. The problem of the mechanism of the polymerization of acetylene is discussed. 4. A method of separation and collection of the reaction products by absorption in solvents is described. 5. A method for the discontinuous synthesis of chloroprene without excess pressure is described. 6. A procedure for the continuous production of chloroprene from pure monovinylacetylene and its mixture with acetylene is described. 7. The conditions of the polymerization of chloroprene to α-polymer are described, with particular reference to the conditions which inhibit the formation of rapidly aging and hardening polymers. The latter are considered as balata-like products. 8. A process of polymerization in solvents, with formation only of the α-polymer is described.