An acetylene end-capped polyimide oligomer having the structure: ##STR16## where R has the structure: ##STR17## ##STR18## where X is --CF2 --, or a bond, where R' is selected from the group consisting of a phenylene group, a naphthylene group, or ##STR19## where X is as defined above; and where R is an aryl group bearing a substituent having the structure: ##STR20## and where n has a value of fro