Journal ArticleDOI
End-functionalized thermoplastic-toughened phthalonitrile composites: influence on cure reaction and mechanical and thermal properties
TLDR
In this paper, the feasibility of toughening novolac-phthalonitrile (NPN) resins using chemically modified poly(ether ether ketone) (PEEK).Abstract:
Phthalonitrile polymers are known for their high thermal stability and good mechanical properties. However, their brittle nature limits their application as structural composites in many critical areas. The present study investigates the feasibility of toughening novolac–phthalonitrile (NPN) resin using chemically modified poly(ether ether ketone) (PEEK). A telechelic PEEK bearing a phthalonitrile end group (PEEKPN) was synthesized via nucleophilic substitution of nitrophthalonitrile with the corresponding phenol–telechelic poly(ether ether ketone) (PEEKOH). Different compositions of NPN and PEEKOH–PEEKPN blends with curing agent, i.e. diaminodiphenylsulfone, were investigated for their cure behaviour and mechanical properties of their carbon fabric composites. In NPN–PEEKOH blends, crosslinking of the phthalonitrile groups was facilitated by phenol-mediated reactions resulting in the reduction of cure temperatures by around 130 °C with substantial improvement in thermal stability. Blending the resin with the thermoplastic enhanced the mechanical properties of the composites. The apparent flexural strength and impact strength of carbon fabric-reinforced composites were improved by more than 200 and 150%, respectively, on incorporation of 20 wt% PEEKOH in the NPN matrix. However, higher concentration of PEEKOH had a detrimental effect on the properties. Substitution of phenol end groups by phthalonitrile moieties led to integration of the PEEK moieties with the NPN matrix. However, it was not as conducive as PEEKOH for improving the matrix properties. The better performance of PEEKOH is attributed to the formation of polar heterocyclic groups like isoindoline by way of the phenol–nitrile reaction. © 2014 Society of Chemical Industryread more
Citations
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Journal ArticleDOI
Thermal and mechanical properties enhancements obtained by reinforcing a bisphenol‐a based phthalonitrile resin with silane surface‐modified alumina nanoparticles
Mehdi Derradji,Noureddine Ramdani,Zhang Tong,Jun Wang,Lin-dan Gong,Xiaodong Xu,Zai-wen Lin,Abdelkhalek Henniche,H.K.S. Rahoma,Wen-bin Liu +9 more
TL;DR: In this paper, a new type of nanocomposites based on a high performance bisphenol-A phthalonitrile resin and surface-modified alumina nanoparticles was prepared by a hot compression molding technique.
Journal ArticleDOI
Enhanced thermal properties of phthalonitrile networks by cooperating phenyl-s-triazine moieties in backbones
TL;DR: In this paper, a two-step, one-pot reaction was used to obtain high glass transition temperatures at around 400°C and outstanding thermo-oxidative stability with weight retention of 95% ranging from 539°C to 552°C, suggesting an improvement of thermal properties imposed by phenyl-s-triazine units.
Journal ArticleDOI
One component propargyl phthalonitrile novolac: Synthesis and characterization
TL;DR: In this paper, a number of copolymers bearing varying proportions of propargyl and phthalonitrile groups on the same backbone and capable of self and co-curing to a thermally stable matrix have been synthesized.
Journal ArticleDOI
Phthalonitrile-Terminated Silicon-Containing Oligomers: Synthesis, Polymerization, and Properties
TL;DR: In this article, a silicon-containing phthalonitrile-terminated fluorene-based oligomer was synthesized by a novel method, and the structure was characterized by Fourier transfrom infrared spectroscopy, 1H NM.
Journal ArticleDOI
Studied on mechanical, thermal and dielectric properties of BPh/PEN-OH copolymer
TL;DR: In this paper, a copolymer 4,4′-bis(3,4-dicyanophenoxy)biphenyl (BPh) was modified with the hydroxyterminated poly(aryl ether nitrile) (PEN-OH).
References
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Journal ArticleDOI
Self-promoted curing phthalonitrile with high glass transition temperature for advanced composites
TL;DR: In this paper, a self-promoted curing phthalonitrile monomer was synthesized via substitution reaction of 4-nitrophalonyl and 3-aminophenol at the presence of K2CO3 in the dimethylsulfoxide solvent.
Journal ArticleDOI
Phenol‐containing phthalonitrile polymers – synthesis, cure characteristics and laminate properties
TL;DR: In this paper, the phenol groups in the phthalonitrile backbone were conducive to building a stronger interphase in their carbon composites, resulting in better mechanical properties.
Journal ArticleDOI
Synthesis and thermal properties of bisphthalonitriles containing aromatic ether nitrile linkages
Ronghua Du,Wenting Li,Xiaobo Liu +2 more
TL;DR: In this paper, a low-melting bisphthalonitrile oligomer with variable length of aromatic ether nitrile linkages (nPEN-BAPh) was firstly synthesized and the length of the linkages was controlled by mole ratio of 2, 6-dichlorobenzonitriles and bisphenol A.
Journal ArticleDOI
Synthesis and characterization of self‐catalyzed imide‐containing pthalonitrile resins
TL;DR: Some new amino-and imide-containing phthalonitrile compounds with 1:1 molar ratio of amino group to pthaloniitrile unit were successfully synthesized in this paper.
Journal ArticleDOI
A new soluble aramide with pendant phthalonitrile units and polymer property enhancement by nitrile cure reactions
TL;DR: In this article, a new soluble aramide with pendant phthalonitrile units was prepared, while its properties including solvent resistance and thermal properties can be enhanced by further thermal treatment around the glass transition temperatures of the polymers for an extended period of time.