Journal ArticleDOI
End-functionalized thermoplastic-toughened phthalonitrile composites: influence on cure reaction and mechanical and thermal properties
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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
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Journal ArticleDOI
Improved mechanical properties of basalt fiber/phthalonitrile composites modified by thermoplastic Poly(phthalazinone ether nitrile)s
TL;DR: In this article, the effects of thermoplastic poly(phthalazinone ether nitrile)s (PPEN) and poly(phthalonitrile resin) (PENK) on the mechanical properties of the modified basalt fiber reinforced 4,4′-bis(3,4-dicyanophenoxy)biphenyl (BPh) composite have been assessed.
Journal ArticleDOI
Novolac/Phenol-Containing Phthalonitrile Blends: Curing Characteristics and Composite Mechanical Properties.
TL;DR: The mechanical properties are sensitive to elevated post-cured temperature; this is consistent with the result of morphological investigation using SEM; and the dynamic mechanical analysis indicated that the glass transition temperature heightened with the increase of novolac content and post- curing temperature.
Journal ArticleDOI
Bisphthalonitrile-based Thermosets as Heat-resistant Matrices for Fiber Reinforced Plastics
TL;DR: In this paper, the processes involved in producing heat-resistant matrices for fiber reinforced plastics (FRP) by polymerization of the resins consisting of phthalonitrile monomers and comonomers are discussed.
Journal ArticleDOI
Toughening effect of self-assembled thermoplastic particles on phthalonitrile containing benzoxazine and improved mechanical properties in the presence of fibers reinforcement
TL;DR: In this article , the effect of poly (arylene ether nitrile) containing phenolphthalein (PP-PEN) was introduced by solution blending to toughen BA-ph and its glass fiber (GF) FRC.
Journal ArticleDOI
Novel low-melting bisphthalonitrile monomers: Synthesis and their excellent adhesive performance
Liu Caizhao,Liu Caizhao,Bin Zhang,Bin Zhang,Sun Mingming,Xiang Liu,Xugang Zhang,Jianhui Li,Lei Wang,Heng Zhou +9 more
TL;DR: In this paper, the authors introduced the asymmetric structure concept to improve the processability of bisphthalonitrile and showed that the incorporation of asymmetric structures results in an amazing adhesive performance, which is comparable with commercial polyimides but coupled with a thermal stability tradeoff.
References
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Advanced Organic Chemistry: Reactions, Mechanisms, and Structure
TL;DR: Localized Chemical bonding Delocalized Chemical Bonding Bonding Weaker than Covalent Stereochemistry Carbocations, Carbanions, Free Radicals, Carbenes and Nitrenes Mechanisms and Methods of Determining them Photochemistry Acids and Bases Effects of Structure on Reactivity Aliphatic Nucleophilic Substitution Aromatic Electrophilic Substitutes Aliphatically Electrophilic Substitution Free-Radical Substitution Addition to Carbon-Carbon Multiple Bonds Adding to Carbon Hetero Multiple Bonds Eliminations Rearrangements Ox
Journal ArticleDOI
Synthesis and characterization of sulfonated poly(ether ether ketone) for proton exchange membranes
Peixiang Xing,Peixiang Xing,Gilles P. Robertson,Michael D. Guiver,Serguei D. Mikhailenko,Keping Wang,Serge Kaliaguine +6 more
TL;DR: In this article, a series of sulfonated poly(ether ether ketone)s (SPEEKs) were prepared by sulfonation of commercial Victrex ® and Gatone ® PEEK for a comparative study of proton exchange membranes (PEM) intended for fuel cell applications.
Journal ArticleDOI
Syntheses and characterization of heteroatom-bridged metal-free phthalocyanine network polymers and model compounds
TL;DR: In this paper, le polymeres et composes modeles ont une resistivite electrique elevee and ne peuvent etre dopes par l'iode.
Journal ArticleDOI
Synthesis and properties of a bisphenol A based phthalonitrile resin
TL;DR: In this article, a multiple aromatic ether linked phthalonitrile was synthesized and characterized, which exhibited good structural integrity upon heating to elevated temperatures and exhibited excellent thermal properties along with long-term oxidative stability.
Journal ArticleDOI
Phthalonitrile cure reaction with aromatic diamines
Satya B. Sastri,Teddy M. Keller +1 more
TL;DR: In this paper, a sulfone-containing diamine, bis[4-(4-aminophenoxy)phenyl] sulfone (p-BAPS), was used for phthalonitrile cure.