2025 Volume 61 Issue 7 Pages 193-199
Many polyimide-based carbon fiber composites have been developed as lightweight materials in place of alloys of aluminum, steel and titanium in aerospace components used for high temperature applications. However, it has been difficult to design the 1st and 2nd ordered chemical structures of imide resins which enable to realize both high proessability for molding composites and high thermal stability after curing. We prepared phenylethynyl （PEPA） terminated imide oligomers derived from 1,2,4,5-benzenetetracarboxylic dianhydride（PMDA） and 2-phenyl-（4,4’-diaminodiphenyl ether）（2 -Ph-ODA）with asymmetric and non-planar structure for the polyimide matrix resin of high heat resistant carbon fiber reinforced plastics（CFRPs）. The imide oligomers showed good minimum melt viscosity at higher than 300℃ for molding the cured resin films with good thermal and mechanical properties. Cured resin film showed a high Tg at 350℃ and Td5 at 550℃. Surprisingly, the elongation-at-break of the cured resin was found to be extremely high（>15%）. Preliminaryresults for proessing of carbon fiber fabric prepregs using corresponding amic acid oligomer （precursor of imide oligomer） solution, thermal behavior of the imide resin in the prepreg before and after curing, and outstanding thermal and mechanical properties of CFRPs at both room and elevated temperature are reported
