Synthesis,characterization, and gas transport properties of new semifluorinated poly(ether imide)s containing cardo moiety

A series of new semifluorinated poly(ether imide)s (PEI)s was synthesized from a diamine monomer, 9,9‐bis ‐[3‐phenyl‐4‐{2′‐trifluoromethyl‐4′‐(4′′‐aminophenyl)phenoxy} phenyl]fluorene on reaction with three different aromatic dianhydrides namely, 4,4′‐(4,4′‐isopropylidenediphenoxy)bis (phthalic anhydride), 4,4'‐(hexafluoro‐isopropylidene)diphthalic anhydride, and 4,4'‐oxydiphthalic anhydride. The PEIs were well characterized by elemental analysis, spectroscopic, thermal, mechanical, electrical, and optical techniques. The synthesized PEIs showed high glass transition temperature (T_g up to 288 °C) and high thermal stability (T_{d ,10} up to 521 °C under synthetic air), high tensile strength, up to 76 MPa and low dielectric constant (?) (2.35–2.61 at 1 MHz). The membranes prepared from these polymers were studied for their gas permeability for four different gases CO₂, O₂, N₂, and CH₄. The PEI membranes showed high gas permeability (P _CO2 up to 70.3 and P _O2 up to 16.7 Barrer) and high permselectivity (P _CO2/P _CH4 up to 73.6 and P _O2/P _N2 up to 13.4); for the O₂/N₂ gas pair the PEIs surpassed the present upper boundary limit of 2008 drawn by Robeson. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45213.     

Hydrophobic properties of poly(arylene ether)s derived from linear polydimethysiloxanes and decafluorobiphenyl

A series of novel poly(arylene ether)s were synthesized with diphenol liner polydimethysiloxanes with different silicon numbers (2OH‐PDMS‐P; P = 2, 6, 10, 12, 16) and decafluorobiphenyl via a two‐step nucleophilic substitution polymerization. The chemical structures of the polymers were confirmed by Fourier transform infrared spectrometer, ¹⁹F‐NMR and ¹H‐NMR spectra. All the polymers provided outstanding hydrophobic properties, high thermal stability and good solubility. The water contact angle (WCA) first increased and then suddenly decreased with the increasing of silicon numbers in PDMS. The highest WCA about 112° was obtained when silicon numbers was ten. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46187.     

Preparation and Characterization of high‐strength poly(ether ether ketone) films

High‐strength poly(ether ether ketone) (PEEK) films were prepared through melt extrusion followed by stretching. The tensile strength, orientation, and crystallization behaviors of PEEK films were characterized by universal testing machine, thermomechanical analysis, wide‐angle X‐ray diffraction, and differential scanning calorimetry. The results indicated that the tensile strength of PEEK films mainly depended on the stretching rate (ν), stretching temperature (T), and stretching ratio (λ_L). Moreover, the tensile strength of the stretched PEEK film (333 MPa) was almost four times higher than that of the unstretched PEEK film (87 MPa) under an optimized condition. This is attributed to a synergistic effect of orientation and crystallization in the stretching process, and the influence of orientation is stronger than that of the crystallization on the improvement of the tensile strength of PEEK films. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40172.     

Synthesis and properties of thio‐containing poly(ether ether ketone)s

A series of thio‐containing poly(ether ether ketone) (PEESK) polymers was synthesized by the introduction of thio groups from 4,4′ thiodiphenol (TDP) into the poly(ether ether ketone) (PEEK) structure via reaction between the phenol and aromatic fluoride groups. The effect of the thio groups on the properties of the PEESK materials was investigated. Differential scanning calorimetry (DSC) analysis and X‐ray diffraction (XRD) patterns show a depression in the crystallinity of the PEESKs with incorporation of the content of thio groups in the backbones. The crystalline structure was identified as an orthorhombic structure with lattice constants of a = 7.52 Å, b = 5.86 Å and c = 10.24 Å for all crystallizable PEESKs. The crystalline structures of the thio‐containing PEEK polymers were the same as that of the neat PEEK, which means the thio‐containing block in the whole thio‐containing PEEK molecule is almost excluded from the crystalline structure and the crystals are completely formed by ‘non‐thio’ blocks only. Due to the glass transition temperature (T_g) and melting temperature (T_m) depression with increase in the TDP content in the reaction system, the processability of the resultant thio‐containing PEEKs could be effectively improved. Copyright © 2004 Society of Chemical Industry     

Polyimides 7: Synthesis,characterization, and properties of novel soluble semifluorinated poly(ether imide)s

Three novel diamine monomers ( VI , VII , and VIII ) were synthesized. These diamine monomers lead to a number of semifluorinated poly(ether imide)s when reacted with different commercially available dianhydrides like pyromellitic dianhydride (PMDA), benzophenone tetracarboxylic acid dianhydride (BTDA), 2,2‐bis (3,4‐dicarboxyphenyl) hexafluoropropene (6FDA), and oxydiphthalic dianhydride (ODA) by thermal imidization route. Elemental analyses, IR and NMR techniques were used to characterize the monomers and polymers. The resulting polymers exhibited weight average molar masses up to 1.78 × 10⁵ g mol^?1 in GPC with respect to polystyrene standard and have very good solubility in several organic solvents such as NMP, DMF, DMAC, DMSO, chloroform, and THF. Very good solubility of these polymers in CDCl₃ enables their complete characterization by proton as well as ¹³C‐NMR techniques. The polymers showed very high thermal stability with decomposition temperature (5% weight loss) up to 511°C in air and high glass transition temperature up to 311°C depending upon the exact repeating unit structure. The polymer films showed high modulus (up to 2.9 GPa) as was evaluated by DMA. The polymers also showed very low water absorption (0.16%), low dielectric constant (2.35 at 1MHz) and very good optical transmission. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3025–3044, 2007     

Poly(arylene ether nitrile) copolymers containing pendant phenyl: Synthesis and properties

A series of poly(arylene ether nitrile) copolymers (PENAPs) were synthesized with bisphenol A (BP-A), bisphenol AP (BP-AP) and 2,6-Dichlorobenzonitrile (DCBN) via a nucleophilic substitution polycondensation reaction. FTIR and ¹H-NMR were used to confirm the structure of PENAPs. Glass transition temperature (T_g) of PENAPs determined by differential scanning calorimetry (DSC) ranged from 154.2 to 200.8°C. The 5% weight lost temperature (T_5%) of PENAPs were 418.9–447.7°C. The tensile and DMA test indicated that PENAPs possessed excellent mechanical properties with tensile strength more than 92.8 MPa and storage modulus more than 1.0 GPa at about 150°C. The melt flowability was measured by rheology properties testing ranging from 80 to 1639 GPa at 290°C and under shear frequency 100 Hz, which indicated the copolymers had good flowability and thermal stability. Additionally, PENAPs could be dissolved in many solutions, which meant PENAPs had good solubility and can be processed by solution method.     

Novel poly(arylene ether)s containing multi-substituted pentaphenylene moiety

Three novel 2-trifluoromethyl-activated bisfluoro monomers have been synthesized successfully using a Suzuki-coupling reaction of 4-fluoro-3-trifluoromethyl phenyl boronic acid with 4,4′-dibromo-p-terphenyls with varied phenyl substitution on the middle phenylene ring. Three monomers were converted to a series of phenyl substituted poly(arylene ether)s by nucleophilic displacement of the fluorine atoms on the terminal benzene ring with several bisphenols. The polymers obtained by displacement of the fluorine atoms exhibit weight-average molecular weight up to 2.25 × 10⁵ g/mol in GPC. Thermal analysis studies indicated that these polymers did not show melting endotherms but did show ultrahigh T_g values up to 334 °C in DSC and outstanding thermal stability up to 671 °C for 5% weight loss in TGA under nitrogen atmosphere. The polymers are soluble in a wide range of organic solvents: THF, CHCl₃, NMP, DMAc, DMF, toluene, etc., and are insoluble in DMSO and acetone at room temperature. Transparent and flexible films were easily prepared by solution casting from chloroform solution of each of the polymers. The UV absorption spectra of thin films showed no absorption in the visible light region of the spectrum, suggesting a good application to optical transparent materials in the visible light region of the spectrum.     

Synthesis of poly(arylene ether nitrile ketone)s bearing phthalazinone moiety and their properties

Copoly(arylene ether nitrile ketone)s bearing phthalazinone moiety (PPENKs) were successfully synthesized by the nucleophilic substitution reaction of 4-(4-hydroxylphenyl)-2,3-phthalazin-1(2H)-one (DHPZ), a new bisphenol-like monomer with twisted non-coplanar structure, with various molar proportions of 2,6-dichlorobenzonitrile (DCBN) to 4,4′-difluoro benzophenone (DFK) as coreactants in sulfolane at the present of anhydrous potassium carbonate. In order to obtain high-molecular weight polymers, DHPZ firstly polymerized with low-reactive DCBN for a given time at polymerization temperature after removal of water produced during the reaction, followed by addition of high-reactive DFK to continue the reaction until high-molecular weight polymers were obtained. These obtained copolymers had inherent viscosities between 0.45 and 0.80 dL/g in chloroform at a concentration of 0.5 g dL^?1 at 25 °C, and their number-average molecular weights were in the ranges from 2.2 × 10⁴ to 4.7 × 10⁴ with the polydispersity of 2.05–2.70. The structure of typical PPENK5050 was ambiguously confirmed by FT-IR and ¹H-NMR. All of the PPENKs were amorphous and soluble in dipolar aprotic solvents, involving N-methyl pyrrolidione, N,N-dimethylacetamide, and chloroform at room temperature. The resulting copolymers showed glass transition temperatures (T _gs) between 267 and 287 °C, and the T _g values of the copolymers were found to increase with increasing DCBN unit content in the polymer. Thermogravimetric studies showed that all of the polymers had 5 % weight loss temperatures ranging from 501 to 511 °C in nitrogen atmosphere. All of the PPENKs could be cast into transparent, strong, and flexible films. They displayed electrical surface resistivity of 10¹³ Ω, indicating their potential application in electronic field. Physical properties of PPENK5050, which exhibited the best mechanical properties, were measured according to ASTM plastic standards. The results indicated that PPENK5050 possessed excellent thermal properties with the heat deformation temperature of 270 °C, which was 100 °C higher than PEN? invented and commercialized by Idemitsu Kosan Company Limited. Its dielectric coefficient was 3.45 with the dielectric loss of 0.004 detected at 1 MHz. The other properties of PPENK5050 were equivalent to PEN?. They could be the promising materials as high-performance matrix in the application of polymer matrix composite, high-performance coating, adhesive, and membrane.     

Synthesis and properties of crosslinked poly(arylene ether nitriles) containing pendant phthalonitrile

In this study, poly(arylene ether nitriles) containing pendant carboxyl groups (PEN‐COOH) was first synthesized via nucleophilic aromatic substitution reaction from phenolphthalein, hydroquinone and 2,6‐dicholorobenzonitrile. Then, poly(arylene ether nitriles) with pendant phthalonitrile groups (PEN‐CN) was obtained via the Yamazaki–Higashi phosphorylation route from 4‐(4‐aminophenoxy)phthalonitrile (APN) with PEN‐COOH in the presence of CaCl₂, thus the phthalonitrile as pendant groups in PEN‐CN were easily crosslinked by further thermal treatment. The effect of crosslinking density on the thermal stabilities, dielectric properties and water absorption of the PEN‐CNs was investigated. These results showed that the T_g of PEN‐CN was improved from 182 to 213°C, dielectric constant (ε) was increased from 3.1 to 3.9, and dielectric loss (tan δ) was decreased from 0.090 to 0.013 at 1 kHz. The water absorption of PEN‐CNs after thermal crosslinking was <1.01 wt %, which showed excellent water resisting property. Therefore, this kind of poly(arylene ether nitriles) containing pendant phthalonitrile could be a good candidate as matrix resins for high‐performance polymeric materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and ferroelectric investigations of poly(vinylidene fluoride‐co‐hexafluoropropylene)‐Mg(NO3)2 films

The free‐standing, flexible, and ferroelectric films of poly(vinylidenefluoride‐co‐hexafluoropropylene) [P(VDF‐HFP)] were prepared by spin coating method. The ferroelectric phase of the films was enhanced by adding magnesium nitrate Mg(NO₃)₂ in different wt % as the additive during the film fabrication. The effects on the structural, compositional, morphological, ferroelectric, dielectric, and leakage current behaviors of the films due to the addition of salt were analyzed. Based on the X‐ray diffraction (XRD) patterns and Fourier Transform Infrared (FTIR) spectra, it is confirmed that the addition of Mg(NO₃)₂ promotes the electroactive β phase that induces the ferroelectric property. The fiber‐like topography of the films exhibits a nodule‐like structure, and the roughness of the films increases by the addition of Mg(NO₃)₂. The ferroelectric studies show the higher polarization values for the composite films than that of the plain P(VDF‐HFP) film. The Piezo‐response force microscope images also confirm the domain switching behavior of the samples. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44008.     

Synthesis and properties of novel phosphorus‐containing poly(ether ether ketone ketone)s

A novel monomer, bis[4‐(4‐fluorobenzoyl)phenyl]phenylphosphine oxide, was synthesized through the reaction of bis(4‐chloroformylphenyl) phenyl phosphine oxide with fluorobenzene. Three poly(ether ether ketone ketone)s derived from bis[4‐(4‐fluorobenzoyl)phenyl]phenylphosphine oxide and different aromatic bisphenols were prepared by aromatic nucleophilic substitution reactions. The resulting polymers had inherent viscosities in the range of 0.55–0.73 dL/g. The structures of the poly(ether ether ketone ketone)s were characterized with Fourier transform infrared and ¹H‐NMR. Thermal analysis indicated that the glass‐transition temperatures of the poly(ether ether ketone ketone)s were higher than 200°C, and the 5% weight loss temperatures in nitrogen were higher than 463°C. All the polymers showed excellent solubility in polar solvents such as N‐methyl‐2‐pyrrolidone, dimethylformamide, and dimethylacetamide and could also be dissolved in chlorinated methane. The polymers afforded transparent and flexible films by solvent casting. Organic phosphorous moieties also imparted good flame‐retardancy to the polymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and properties of sulfonated poly(arylene ether nitrile) copolymers containing carboxyl groups for proton‐exchange membrane materials

A series of sulfonated poly(arylene ether nitrile) copolymers containing carboxyl groups were synthesized via a nucleophilic aromatic substitution reaction from phenolphthalein, hydroquinone sulfonic acid potassium salt, and 2,6‐difluorobenzonitrile in N‐methyl pyrrolidone (NMP) with K₂CO₃ as a catalyst. The synthesized copolymers had good solubility in common polar organic solvents and could be easily processed into membranes from solutions of dimethyl sulfoxide, NMP, N,N′‐dimethyl acetylamide, and dimethylformamide. Typical membranes in acid form were gained, and the chemical structures of these membranes were characterized by Fourier transform infrared analysis. The thermal properties, fluorescence properties, water uptake, ion‐exchange capacity, and proton conductivities of these copolymers were also investigated. The results indicate that they had high glass‐transition temperatures in the range 151–187°C and good thermal stability, with the 10 wt% loss temperatures ranging from 330 to 351°C under nitrogen. The copolymers showed characteristic unimodal ultraviolet–visible (UV–vis) absorption and fluorescence emission, and the UV–vis absorption, fluorescence excitation, and emission peaks of the copolymers were obvious. Moreover, the copolymer membranes showed good water uptake and proton conductivities at room temperature and 55% relative humidity because of the introduction of both sulfonic acid groups and carboxyl groups into the copolymers, whose contents were in ranges 18.45–67.86 and 3.4 × 10^?4 to 3.0 × 10^?3 s/cm, respectively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40213.     

Thermal properties of melt‐blended poly(ether ether ketone) and poly(ether imide)

The thermal properties of blends of poly(ether ether ketone) (PEEK) and poly(ether imide) (PEI) prepared by screw extrusion were investigated by differential scanning calorimetry. From the thermal analysis of amorphous PEEK–PEI blends which were obtained by quenching in liquid nitrogen, a single glass transition temperature (T_g) and negative excess heat capacities of mixing were observed with the blend composition. These results indicate that there is a favorable interaction between the PEEK and PEI in the blends and that there is miscibility between the two components. From the Lu and Weiss equation and a modified equation from this work, the polymer–polymer interaction parameter (χ₁₂) of the amorphous PEEK–PEI blends was calculated and found to range from −0.058 to −0.196 for the extruded blends with the compositions. The χ₁₂ values calculated from this work appear to be lower than the χ₁₂ values calculated from the Lu and Weiss equation. The χ₁₂ values calculated from the T_g method both ways decreased with increase of the PEI weight fraction. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 733–739, 1999     

Synthesis of soluble and thermally stable poly[arylene ether amide (N‐arylenebenzimidazole)]s

Poly(arylene ether)s containing N‐arylenebenzimidazole and amide groups were prepared using an aromatic nucleophilic displacement reaction that replaced the N‐H sites from four different bis(benzimidazolyl) derivatives with activated aromatic difluorides containing ether and amide groups in sulfolane. The reaction was carried out at 210 °C in the presence of anhydrous potassium carbonate. The structures of the polymers were characterized by means of Fourier transform infrared, ¹H NMR spectroscopy and elemental analysis, and the results were largely consistent with the proposed structure. All resulting polymers showed an essentially amorphous nature. This was consistent with the calculated results. Differential scanning calorimetry and thermogravimetric measurements showed that the polymers had high glass transition temperatures (>190 °C), good thermostability and high decomposition temperatures (>400 °C). These novel polymers also showed easy solubility. Copyright © 2012 Society of Chemical Industry     

Synthesis and characterization of poly(ether ketone ketone) (PEKK)/sodium sulfonated poly(arylene ether ketone) (S‐PAEK) block copolymers

A series of well‐defined poly(ether ketone ketone) (PEKK)/sodium sulfonated poly(aryl ether ketone) (S‐PAEK) block copolymers of high molecular weights was prepared by direct nucleophilic polymerization of hydroquinone with sodium 5,5′‐carbonylbis(2‐fluorobenzene sulfonate) ( 1 ) and PEKK oligomer ( 2 ). Varying the ratio of 1 to 2 used in polymerization can be used to control the degree of polymer sulfonation, which correspondingly affects the polymer solubility in solvents. Increasing content of 1 in the copolymers, slightly decreases their thermal stability which is nevertheless thermally stable up to 400 °C. Two T_g values, or one broad T_g, were observed in the DSC measurements of the block copolymers, indicating the existence of phase separation, which was further proved by phase‐separated morphologies as shown in atomic force microscopy images. © 2001 Society of Chemical Industry     

Characterization of the thermoresponsive shape‐memory effect in poly(ether ether ketone) (PEEK)

We conducted a systematic experimental investigation to characterize the shape‐memory effect in a commercial poly(ether ether ketone) (PEEK), which is a very important high‐temperature polymers at present. The focus was on the influence of the programming conditions and heating temperature for recovery on the shape‐recovery ratio (R_r). We concluded that PEEK is not only an important engineering polymer as it is traditionally known but is also an excellent high‐temperature shape‐memory polymer. For a residual programming strain of 30%, the maximum R_r was about 90%. It was revealed that it was practically feasible to program PEEK at room temperature and to lower the recovery temperature from its melting temperature range to around its glass‐transition temperature. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39844.     

Effects and properties of poly(arylene ether benzonitrile)s of various molecular weights blended with sulfonated poly(ether ether ketone)

Poly(arylene ether benzonitrile) (PAEBN) was synthesized with 2,6‐dichlorobenzonitrile and biphenol. PAEBNs with various molecular weights (MWs), 1,640,000 and 185,000 g/mol, were synthesized by control of the stoichiometry of the monomers and were blended with sulfonated poly(ether ether ketone) (SPEEK). The effects of MW on the water uptake, swelling, methanol permeability, and proton conductivity of the SPEEK/PAEBN blend membranes were investigated. The molecular mobility of the SPEEK/PAEBN blends was also examined in this study. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

High dielectric constant polyaniline/sulfonated poly(aryl ether ketone) composite membranes with good thermal and mechanical properties

All‐organic polyaniline (PANI)/sulfonated poly(aryl ether ketone) (SPAEK) composite membranes consisting of a PANI (conducting) filler evenly distributed in an SPAEK (insulating) matrix were prepared with a solution‐blending technique. The dielectric properties, electrical conductivity, and thermal and mechanical performances of the all‐organic PANI/SPAEK composite membranes were investigated as a function of different PANI loading levels. The composite membrane containing 30 wt % PANI exhibited a high dielectric constant of about 600, a low dielectric loss tangent of about 0.6 (at 1 kHz), and good thermal properties (temperature for 5% weight loss > 250°C) and mechanical properties (tensile strength ≈ 35 MPa). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1990–1995, 2013     

Gas transport properties in (6FDA‐RTIL)‐(6FDA‐MDA) block copolyimides

This article reports synthesis and structure property studies of block copolyimides synthesized using diamino room temperature ionic liquids (RTIL) as diamine monomers. Specifically, polyimide oligomers of different lengths were synthesized using 2,2‐bis (3,4‐carboxylphenyl) hexafluoropropane dianhydride (6FDA) and diamino RTIL (1,3‐di(3‐aminopropyl) imidazolium bis[(trifluoromethyl) sulfonyl] imide). These oligomers were copolymerized with 6FDA and m‐phenylenediamine (MDA) using in situ polymerization to form (6FDA‐RTIL)‐(6FDA‐MDA) block copolyimides. The impact of the length and relative concentration of 6FDA‐RTIL oligomer in the copolymer on the resulting thermal, physical, and gas transport properties was monitored. As the concentration of the 6FDA‐RTIL segments increased, the backbone of the block copolyimides became more flexible resulting in a decrease in the glass transition temperature (T_g) and an increase in the density. The permeabilities of the RTIL containing copolyimides were consistently lower than those of the base polyimide, 6FDA‐MDA, with some increase in selectivities. Interestingly, the permeabilities of films produced with the low molecular weight oligomers were very different than those produced with same composition of the high molecular weight oligomers. This may be indicative of very different morphologies within these copolyimides. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43077.     

Semi-aromatic copoly(ether ether amide): Synthesis and properties

A series of semi-aromatic copoly(ether ether amide)s (hydroquinone (HQ) (0%)-HQ (100%)) were synthesized by 1,1-bis(4-hydroxyphenyl)-1-phenylethane (BHPPE), 1,4-benzenediol (HQ) and 1,6-N,N′-bis(4-fuorobenzamide) hexane (BFBH) in this work. The inherent viscosities of copoly(ether ether amide)s were in the range of 0.487–0.769 dl g⁻¹. Following with increase of the content of HQ, the resultant polymers were converted from amorphous to crystalline. The copolymers were found to have high glass transition temperatures (T_g) of 141.4–155.6°C and weight-loss temperature (T_5%) of 423.3–434.3°C. They can be hot-pressed into films with tensile strength of 63.3–87.6 MPa, and storage modulus over 0.8 GPa at about 150°C, indicating good thermal and mechanical property of the obtained copolymers. The results of rheological property showed that the copolymers had good melt flowability and thermal stability. Additionally, the introduction of HQ improved the corrosion resistance of copolymers, the obtained polymers HQ (60%), HQ (80%) and HQ (100%) exhibited better corrosion resistance than that of HQ (0%). Especially, HQ (80%) and HQ (100%) were insoluble in organic polar solvents such as DMSO, DMF because of their crystalline nature, indicating that they had potential to be applied to the corrosion-resistant materials.