SILICONES— A NEW CONTINENT IN THE WORLD OF 



CHEMISTRY 1 



By S. L. Bass 



Assistant General Manager, Dow Corning Corporation 

 Midland, Mich. 



[With 3 plates] 



When Columbus started out, the coast of Europe was well known 

 and the coast of China had been explored. He assumed, therefore, that 

 by sailing west from Europe he would reach the coast of China. No 

 one knew then that a great continent lay between Europe and Asia. 



The same condition was, until quite recently, true in the chemical 

 world. Men had known about inorganic materials such as ceramics, 

 glass, and metals for centuries. They had known of organic mate- 

 rials based principally upon carbon and its compounds for genera- 

 tions and had developed thousands of synthetic organic materials 

 in the more recent past. But no one knew that between these two 

 fields lay a new chemical continent of semi-inorganic materials known 

 today as silicones. Organic chemists started to explore the simple 

 organo-silicon compounds some 50 years ago. It was not until the 

 early 1930's however, when chemists at the Corning Glass Works 

 started to investigate the organo-silicon oxide high polymers that the 

 importance of this new chemical continent began to appear. 



Like glasses and the mineral silicates, of which fibrous glass, mica, 

 and asbestos are familiar forms of heat-resistant insulating materials, 

 the silicones also are derived from silica. Chemically, the silicones, 

 like glass and the mineral silicates, are built upon a heat-stable skele- 

 tal structure of silicon atoms joined to each other through oxygen 

 atoms. In the silicones, however, each silicon atom has attached to 

 it one or more organic groups. 



THE SILICONE MOLECULE ' 



Sand is the source of silicones, just as it is of glass. However, in- 

 stead of its being combined with inorganic oxides from lime and soda, 

 it is altered rather radically by being put through a series of chemi- 



* Reprinted by permission from Electrical Engineering, vol. 66, No. 4, April 1947. 



229 



