Frank Minister and Wojciech Pisula, Evonik Operations GmbH, and Victor Lifton, Evonik Corporation
Silicones or polysiloxanes belong to a class of elastomers and are often referred to as silicone rubber. The prevailing type of polysiloxanes is polydimethylsiloxane (PDMS). Development began in 1940 when Eugene G. Rochow and Richard Müller independently developed the synthesis of methylchlorosilanes directly from elemental silicon. This discovery marked the beginning of a series of important findings on a new class of materials, namely silicone elastomers. The first silicone based product was a coating for the airplane industry, presented in 1942 by Dow. Presently, silicones are used in thousands of applications. Worldwide, the market for silicone consumption shows steady growth year after year.
Owing to the presence and degree of crosslinking, silicones can be characterized as fluids, elastomers and resins. In this classification, elastomers are defined as crosslinked PDMS. Highly crosslinked silicone structures are referred to as resins. Depending on their crosslinking conditions, silicones are divided into room temperature and high temperature cured systems. Room temperature cured silicones include one- and two-part systems, while high temperature cured silicones refer to high consistency rubber (HCR) and liquid silicone rubber (LSR).