Release Time:2019-03-11  Hits:

Indexed by: Journal Article

Date of Publication: 2018-04-05

Journal: JOURNAL OF APPLIED POLYMER SCIENCE

Included Journals: EI、SCIE

Volume: 135

Issue: 13

ISSN: 0021-8995

Key Words: applications; composites; dielectric properties; thermal properties; thermosets

Abstract: High processing viscosity and poor solubility limit the application of heterocyclic polymers for fabricating organic wave-transparent composites for aerospace applications. In this paper, a novel resin, poly(phthalazinone ether bisphenol fluorene) encapped with phthalonitrile (PPEBF-Ph), was synthesized and used as the matrix. Biphenol-based phthalonitrile monomer BP-Ph was also synthesized and blended with PPEBF-Ph to further lower the processing viscosity. Solubility tests showed that the resin was soluble in dimethylformamide, N,N-dimethyl acetamide, N-methylpyrrolidone, dimethyl sulfoxide, chloroform, and other solvents. Differential scanning calorimetry and rheological studies revealed that the mixed resins exhibited low processing viscosity and a wide processing window below the gel temperature. Thermogravimetric analysis indicated that the cured resins were stable below 510-530 degrees C under nitrogen atmosphere after 6h of curing (decreased by 40-60% compared with previous reports on phthalonitrile resin). In air, the char yields of the resins reached 20-30% when heated at 800 degrees C. The composites were reinforced by a quartz fiber cloth and exhibited a dielectric constant of 2.94-3.27 in an electromagnetic field with frequency ranging from 8 to 18 GHz. Retention of the bending modulus exceeded 70% at 400 degrees C according to dynamic mechanical analysis, indicating excellent mechanical stability was obtained. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45976.