Polymers their preparation and uses

摘要

A polymer for use in an optical device comprising a first, optionally substituted, repeat unit of formula and a second, optionally substituted, repeat unit of formula wherein each Ar and Ar′is the same or different and comprises an optionally substituted aryl or heteroaryl group and optionally a third, optionally substituted, repeat unit in a molar ratio of no greater than 5%, the third repeat unit having a formula—Ar—N(Ar)—Ar—and having a single nitrogen atom in its backbone.