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

Abstract

A series of poly(aryl ether ketone) oligomers containing phthalonitrile were synthesized by a direct solution polycondensation, and characterized by fourier transform infrared spectroscopy and hydrogen nuclear magnetic resonance. Differential scanning calorimetry results showed the oligomers had low melting points and large processing windows (103–124°C) in the presence of bis[4‐(4‐aminophenoxy)phenyl]sulfone. The uncured synthesized oligomers had good solubility while the cured samples became insoluble in common organic solvents. Isothermal rheometric analysis showed the rate of phthalonitrile polymerization could be controlled easily by varying concentration of curing additive and curing temperature, which indicated that the oligomers possessed good processability. Gel content measurements demonstrated that the cured oligomers had high crosslinking density with the significantly high gel content over 90.1%. Dynamic mechanical analysis indicated the oligomeric phthalonitrile resins according to our curing procedure possessed good thermal mechanical properties. Thermogravimetric analysis of cured resins showed the highest temperature for 5% weight loss reached 515 and 516°C under nitrogen and air, respectively, and the char yield was over 67% at 800°C, revealing that the phthalonitrile resins possessed excellent thermal and thermo‐oxidative stability. This kind of the oligomeric phthalonitrile resins may be used as a good candidate for high‐performance polymeric materials. POLYM. ENG. SCI., 54:1695–1703, 2014. © 2013 Society of Plastics Engineers

Synthesis and properties of a novel high temperature pyridine‐containing phthalonitrile polymer

“…These values show that both the polymers possess excellent thermal and thermos‐oxidative stabilities owing to the presence of the thermally stable pyridine moieties in the polymer backbone. Furthermore, these thermal data are higher than those of many cured ether‐linked monomers (e.g., BAPh, BPh, 6FPh, BDS, BDCN) and poly (aryl ether)‐based phthalonitrile (e.g., PAEK‐CN, PEN‐t‐Ph, 2CN‐o‐PEEK, and also several oligomers reported by Keller), but somewhat lower than those of cured TDPE 30 and 1,6‐BDCN (The corresponding thermal data of the reported networks are summarized in Supporting Information Table S1).…”

Enhanced thermal properties of phthalonitrile networks by cooperating phenyl-s-triazine moieties in backbones

“…The results disclose that the T g s of 7s were from 418 to 424 C. High diamine loading (6 wt%e10 wt%) would caused a slight decrease of T g . Compared to the poly(aryl ether)-based phthalonitrile oligomers like PAEK-CN [40], PEN-t-Ph [44], , PEN-CN3 [45], and 6 [7b], the T g s of 7s are higher than those of phthalonitrile thermosets (Table S5, column T g ). This is resulted from the contribution of the high-stiff phenyl-s-triazine moieties to the rigidity of the polymer backbone.…”

“…The fact is ascribed to the corresponding increase of the cross-linking density driven by the increasing 6 inclusion. Furthermore, owing to the presence of the thermally stable phenyl-s-triazine units in the polymer backbone, these thermal data are higher than those of many cured poly(aryl ether)-based phthalonitrile networks (e.g., PAEK-CN [40], PEN-t-BAPh [21a], , and also several oligomers disclosed by Keller [3f,9,33,41]), the ether-linked monomers (e.g.,BDS [42], BPh, BAPh, 6FPH [15b], RPh [7a], and monomers 1e3 [16b]), and the self-curable monomers (e.g.,2OeP [16a], 3a-b [39], and 4O-M [3b]), but slightly lower than those of the cured TDPE [13b] and silane-bearing HSiPN-ViSiPN [17] (The corresponding thermal data of the reported networks are summarized in Table S5). However, a certain length of the molecular chain of 5 lowers the cross-linking density of 7 as compared to the above mentioned phthalonitrile monomers, which weakens the role of phenyl-s-triazine groups, in turn to lower the thermal stabilities of (7) after cured with different mass ratios of 6 under N 2 atmosphere.…”

Preparation and properties of film materials of poly(aryl ether ketone)-based phthalonitrile resins

“…In addition, a low melt complex viscosity (0.01–1.0 Pa·s) of phthalonitrile monomers or oligomers enables facile processing by the cost‐effective, non‐autoclavable processing techniques such as RTM, resin infusion molding, and filament winding . During the past 30 years, systematic studies have been conducted at Naval Research Laboratory (NRL) on phthalonitrile resins in terms of cure behaviors, processabilities, and properties of the phthalonitrile resins . Aromatic ether , ketone , and sulfone linkages have been previously introduced into phthalonitrile systems, and this has resulted in polymers with outstanding thermal properties.…”

“…During the past 30 years, systematic studies have been conducted at Naval Research Laboratory (NRL) on phthalonitrile resins in terms of cure behaviors, processabilities, and properties of the phthalonitrile resins . Aromatic ether , ketone , and sulfone linkages have been previously introduced into phthalonitrile systems, and this has resulted in polymers with outstanding thermal properties. Most previous studies on phthalonitrile resins focused on the synthesis of the new phthalonitrile monomers or oligomers having low molecular weights to obtain wide processing temperature windows and low melt complex viscosity.…”