Self-promoted curing phthalonitrile with high glass transition temperature for advanced composites

Abstract

A novel self-promoted curing phthalonitrile monomer was synthesized via substitution reaction of 4-nitrophthalonitrile and 3-aminophenol at the presence of K 2 CO 3 in the dimethylsulfoxide solvent. The phthalonitrile was characterized by Fourier transform infrared spectra, nuclear magnetic resonance, gel permeation chromatography, differential scanning calorimetry, dynamic rheological analysis and thermal gravimetric analysis. The phthalonitrile monomer can be thermally polymerized with self-promoted curing behaviors. The prepolymerization reaction of the phthalonitrile prepolymer was investigated and the phthalonitrile prepolymer exhibited the desirable processing feature. With the curing process of low curing temperature and short curing time, the cured polymers exhibited high glass transition temperatures (241-270°C) and excellent thermal stabilities with the 5 % weight loss temperature (395-441°C). The novel phthalonitrile can be a good candidate as matrix for high performance polymeric materials.

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

“…1. Besides the large band in the wavenumber range from 500 to 900 cm 21 , characteristic of amorphous alumina [36,37], several bands are present for the treated alumina, which are not present for the native alumina nanoparticles. This is related to the grafting of the silane coupling agent on the surface of the nanoparticles.…”

“…This is related to the grafting of the silane coupling agent on the surface of the nanoparticles. For the neat alumina, the broad band at 3,435 cm 21 and the band at 1,633 cm 21 are due to the stretching vibration and bending vibration of the associated hydroxyl due to water absorption [37]. After the [36].…”

“…Fourier transform infrared (FTIR) spectra were recorded by a Perkin-Elmer Spectrum 100 spectrometer in the range of 4,000-500 cm 21 , which was equipped with a deuterated triglycine sulfate (DTGS) detector and KBr optics. The transmission spectra were obtained at a resolution of 4 cm 21 after averaging two scans by casting a thin film on a KBr plate for the monomers and cured samples.…”

Molecular structure, spectroscopic and DFT computational studies on 4,5-bis(tert-butylsulfanyl)phthalonitrile

“…Phthalonitrile resins, as advanced composite matrix materials, have received increasing attention due to their high glass transition temperatures, good mechanical properties, excellent solvent resistance and superior flame resistant properties [5][6][7]. These resins have been considered as an ideal material for applications in various fields such as marine, aerospace and electronic uses [8][9][10][11][12][13]. The phthalonitriles are traditionally used as dyes and pigments [14].…”

Synthesis and properties of poly(aryl ether ketone)‐based phthalonitrile resins

“…In addition, phthalonitrile monomers and oligomers possess a low complex melt viscosity, which enables facile processing by the cost‐effective, nonautoclavable processing techniques such as resin transfer molding, resin infusion molding, and filament winding . However, polymerization of the neat phthalonitrile monomer is extremely sluggish, requiring curing additives such as organic amines, and extended heat treatment at elevated temperature to promote the cure of the phthalonitrile resins . A small processing window (20–30°C) and high processing temperature prevent these resins from being fully utilized for extreme applications, such as in aerospace industry; meanwhile, these disadvantages also cause high cost and processing difficulties .…”