any of various organoelemental compounds of high molecular weight. Depending on the composition of the main and side chains, organoelemental polymers may belong to one of three groups.
The first group comprises polymers that consist of inorganic main chains surrounded by organic groups—for example, polyor-ganophosphazenes (seePHOSPHONITRILIC CHLORIDE), polyorgano-siloxanes, and polyorganosilazanes (seeSILICONES).
The second group consists of polymers with organic-inorganic main chains. Members of this group include carbosilanes, which have the general formula
and carbosiloxanes, which have the general formula
Chelate polymers containing metal atoms that form coordinate covalent bonds with organic ligands also belong to this group, as do organoboron polymers with borazole, phosphine-borine, and carborane rings in the main chain.
The third group consists of polymers with organic main chains—for example, polyalkenyltrialkylsilanes, which have the general formula
and phosphorus-containing polymers of the type
where R represents an organic radical.
Of all the organoelemental polymers, silicones are the most widely used.