Synthesis and Characterization of Reactive End-Capped Poiymide Oligomers

Abstract

Abstract A series of reactive, end-capped, polyimide oligomers has been prepared for possible use as planarizing coatings in the electronics industry. Thus, 1,3-bis(3-aminophenoxy)benzene was treated with various excess amounts of 2,2-bis(3,4-dicarboxyphenyl)hexafluoro-propane dianhydride in m-cresol containing toluene and isoquinoline. The resulting anhydride-terminated amic-acid oligomers were thermally imidized and then allowed to react with 3-aminophenylethyne, 1-phenyl-4-(3-aminophenyl)buta-1-ene-3-yne, 1-phenyl-4-(3-amino-phenyl)-1,3-butadiyne, 2-aminobiphenylene, or 1-phenyl-2-(3-amino-phenyl)ethyne. Thermal imidization of these intermediates produced the corresponding end-capped polyimide oligomers. The white oligomers were soluble in organic solvents, such as diglyme, and had glass transition temperatures (Tg's) between 95 and 145°C. The Tg of an ethynyl-terminated oligomer was reduced from 105 to 62°C upon the incorporation of 20 wt % of the reactive plasticizer bis[2-(3-ethynylphenoxy)ethyl]ether. The oligomers underwent exothermic polymerizations between 225 and 420°C. Their TGA thermograms showed 5% weight losses near 530°C in air.