Compounds of ethynyl aromatic compounds having structure (I), wherein each Ar is an aromatic group of inertly-substituted aromatic group; each R is independently hydrogen, an alkyl, aryl or inertly-substituted alkyl or aryl group; L is a covalent bond or a group which links one Ar to at least one other Ar; n and m are integers of at least 2; and q is an integer of at least 1, form polymers which have high thermal stability. The monomers are useful for coating a wide variety of substances such as dielectric coatings where high thermal resistance is desirable including electronic components such as computer chips.