苯乙炔基封端聚苯基喹恶啉的合成与性能研究

摘要

A series of phenylethynyl-terminated polyphenylquinoxalines (PEPPQs) (PPQ-1 to PPQ-4) were prepared with 4-phenylethynylbenzil (PEBZ) as the terminator and 9,9-bis(4-benziloxyphenyl) fluorene (FLTK) and 3,3',4,4'-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 exhibited good processability with the lowest melting viscosities of 21 Pa · S and 568 Pa · S at about 350°C, 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°C for PPQ-1 and 3251 for PPQ-2, respectively. The cured PEPPQs show good thermal stability with the 5% weight loss temperatures higher than 5501 and residual weight ratio higher than 60% at 750°C. 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%.%以4-苯乙炔基苯偶酰(PEBZ)作为封端剂,以芳香族四酮,9,9-双(4-苯偶酰氧基苯基)芴和芳香族四胺,3,3’,4,4 '-四氨基联苯(BPTA)作为单体,设计并合成了一系列苯乙炔基封端聚苯基喹恶啉(PEPPQ)树脂(PPQ-1～PPQ-4).设计分子量分别为2 500( PPQ-1)、5 000(PPQ-2)、10 000(PPQ -3)以及20 000(PPQ-4).流变分析表明,PPQ-1与PPQ -2具有良好的加工性能,350℃左右的最低黏度分别为21和568 Pa·s.通过热模压工艺制备了PPQ-1和PPQ -2固化样件,Tg分别为338和325℃.固化物具有优良的耐热稳定性,氮气中以10℃/min升温,5％失重温度均在550℃以上,750℃时的残重在60％以上.PPQ -2固化物表现出了良好的力学性能,拉伸与弯曲强度分别为88和155 MPa,断裂伸长率达到7.6％.