A series of phenylethynyl鄄terminated polyphenylquinoxalines (PEPPQs) (PPQ-1 to PPQ-4) were
prepared with 4鄄phenylethynylbenzil (PEBZ) as the terminator and 9,9-bis(4鄄benziloxyphenyl) fluorene (FLTK) and
3,3忆,4,4忆鄄tetraaminobiphenyl (BPTA) as the monomers. The designed molecular weights are 2 500 for PPQ-1, 5 000
for PPQ-2, 10 000 for PPQ-3, and 20 000 for PPQ-4. The rheological measurements show that PPQ-1 and PPQ-2 ex鄄
hibited good processability with the lowest melting viscosities of 21 Pa·s and 568 Pa·s at about 350益, respectively.
Cured PPQ-1 and PPQ-2 samples are prepared via the thermally molding process. The cured PEPPQs show high glass
transition temperatures of 338益for PPQ-1 and 325益for PPQ-2, respectively. The cured PEPPQs show good thermal
stability with the 5% weight loss temperatures higher than 550益and residual weight ratio higher than 60% at 750益.
Cured PPQ-2 resin exhibit good mechanical properties with the tensile and flexural strengths of 88 MPa and 125 MPa,
respectively. The elongation at break of the resin reached 7.6%.