Phthalonitrile‐carbon fiber composites

Abstract

Phthalonitrile polymers offer promise as matrix materials for advanced composite applications. The phthalonitrile monomer is readily converted to a highly crosslinked thermosetting polymer in the presence of thermally stable organic amine catalysts. Rheometric studies were conducted to elucidate the optimum amine concentration for composite formulations. High quality composite panels were processed in an autoclave using unsized IM7 carbon fibers. Mechanical properties of the phthalonitrile/carbon composite are either better than or comparable to the state‐of‐the‐art PMR‐15 composites. Dynamic mechanical analysis reveal that samples postcured at elevated temperatures (375°C) do not exhibit a glass transition temperature up to 450°C and also retain °90% of their initial modulus at 450°C. Flame resistance of phthalonitrile/carbon composites, evaluated by cone calorimetric studies, excels over that of other polymeric composites for marine applications. The composites also show low water uptake, <1% after exposure to water for 16 months.

Thermal and mechanical properties enhancements obtained by reinforcing a bisphenol-a based phthalonitrile resin with silane surface-modified alumina nanoparticles

“…Phthalonitrile resin, first developed by the U.S Naval Research Laboratory and further designated as the only candidate to satisfy the flame standards of the United States Navy (MIL-STD-2031) [2], shows exceptional properties superior in many ways to other high performance thermosets such as polyimide [3] and polybenzoxazine [4].…”

The curing behavior and properties of phthalonitrile resins using ionic liquids as a new class of curing agents

“…The maximum amount of water absorbed over this time period were approximately 3.24 and 6.89% by weight for Resin-1 and Resin-2, respectively, which were relatively higher than PN cured by aromatic diamine [1]. The result indicated that the content of [EPy]BF 4 , as a kind of ILs easy to absorb water, has an influence on the water absorption of resulting resins. So we may be able to limit the water absorption capabilities of PN resins by changing the mass ratio of ILs or choosing some ILs that have higher hydrophobicity, e.g.…”

“…These excellent high-temperature properties make the PN resins attractive for many military and civilian advanced technological applications, such as composite matrices [3,4], adhesives [5], electrical conductors [6], and carbon precursors [7]. However, the polymerization of neat PN compound is extremely sluggish, the high curing-temperature of PN resins limited their further applications [1].…”

Thermal characteristics and pyrolysis of methyl‐di(phenylethynyl)silane resin

“…The main advantage of these materials is their high processability, and can be cured without evolution of volatiles and high char yields. 1,2 One disadvantage of the current commercial acetylene-based organic polymers is its low thermal stability, generally being limited to be used with temperature below 3008C. One practical approach to improve the thermal stability of the material is to incorporate inorganic elements such as silicon into the acetylene resins.…”