Synthesis, characterization and optical properties of fluorinated poly(aryl ether)s containing phthalazinone moieties

A series of novel fluorinated poly(aryl ether)s containing phthalazinone moieties (FPPEs) have been prepared by a modified synthetic procedure for optical waveguide applications. The obtained random copolymers exhibited excellent solubility in polar organic solvents, high glass transition temperatures (T_gs: 185-269 °C), good thermal stabilities (the temperatures of 1% weight loss: 487-510 °C) and good optical properties. By adjusting the feed ratio of the reactants, the refractive indices of TE and TM modes (at 1550 nm) could be well controlled in the range of 1.575-1.498 and 1.552-1.484, respectively. The optical losses of the FPPEs exhibited relatively low values (less than 0.27 dB/cm at 1310 nm). Additionally, the thermo-optic coefficient (dn/dT) values of the FPPEs at 1310 nm and 1550 nm (TE mode) ranged from −0.97 × 10⁻⁴ °C to −1.33 × 10⁻⁴ °C and from −0.96 × 10⁻⁴ °C to −1.29 × 10⁻⁴ °C, respectively.     

Synthesis and characterization of novel photo‐crosslinkable fluorinated poly(phthalazinone ether)s for optical waveguides

A series of novel photo‐crosslinkable fluorinated poly(phthalazinone ether)s containing 1,1‐diphenylethylene segments in the polymer main chain, used for optical waveguide materials, were synthesized by polycondensation reaction of decafluorobiphenyl with a mixture of 4‐(4‐hydroxylphenyl)(2H)‐phthalazin‐1‐one (DHPZ), 4,4‐(hexafluoroisopropylidene)diphenol and 1,1‐bis(4‐hydroxyphenyl)ethylene (BHPE) as co‐reactant. The feed ratio of DHPZ to total bisphenols varied from 0 to 80 mol%, while that of BHPE remained at 20 mol% for all polymers. The obtained copolymers show good solubility in some common polar organic solvents. The resulting polymers were photo‐crosslinked after UV irradiation for 10 min in the presence of a photoinitiator. The cured polymers show good chemical resistance, high thermal stability (temperatures of 1% mass loss after curing of 472–496 °C under nitrogen) and high glass transition temperatures (160–249 °C) which could be further increased by about 10 °C after photochemical crosslinking. By adjusting the copolymerizing bisphenol content, the refractive indices of transverse electric and transverse magnetic modes (at 1550 nm) of films of the polymers were exactly tuned in the range 1.5029–1.5661 and 1.4950–1.5502, respectively. The propagation losses of the cured films were measured and found to be less than 0.3 dB cm^?1 at 1550 nm, indicating the promise of these materials for passive optical waveguide devices. Copyright © 2011 Society of Chemical Industry     

Synthesis, characterization and optical properties of cross-linkable poly(phthalazinone ether ketone sulfone)

Cross-linkable poly(phthalazinone ether ketone sulfone) bearing tetrafluorostyrene groups (PPEKS-FSt) has been prepared by copolycondensation reaction for optical waveguide applications. The resulting amorphous polymer exhibits good solubility in some common polar organic solvents (e.g., N,N′-dimethylacetamide, N-methyl-2-pyrrolidinone, chloroform) at room temperature, and can be easily spin-coated into thin films with good optical quality. The glass transition temperature (T_g) and the temperature of 1% weight loss (1% T_d) are 261 °C and 494 °C, respectively, which could be further increased by 31 °C and 14 °C upon thermal cross-linking. The cross-linked polymer thin films exhibit high refractive index (∼1.65, TE mode), high thermo-optic coefficient value (dn/dT) (−1.455 × 10⁻⁴/°C, TE mode), low optical loss (less than 0.24 dB/cm at 1310 nm) and relatively low birefringence (∼0.007).     

Fluorinated poly(arylene ether sulfone)s for polymeric optical waveguide devices

Pentafluorophenyl sulfone was prepared by oxidation of pentafluorophenyl sulfide. Ethynyl terminated fluorinated poly(arylene ether sulfone) (EFPAESO) was synthesized via nucleophilic aromatic substitution from 4,4′-(hexafluoroisopropylidene) diphenol or 4,4′-(trifluoromethylphenylisopropylidene) diphenol with an excess of pentafluorophenyl sulfone, followed by reaction with 3-ethylnylphenol. The molecular weights (M_ns) of the polymers determined by GPC with polystyrene standard were in the range of 6,400-17,200 and polydispersities (M_w/M_ns) were in the range of 2.25-3.19. This EFPAESO showed very high thermal stability up to 479 °C for 5% weight loss in TGA in air. T_g of the polymer was changed from 148 to 196 °C after curing. The cured films showed good chemical resistance and high thermal-stability. At 1550 nm wavelength, the refractive indices of the copolymer films were in the range of 1.5037-1.5504 and birefringences were in the range of 0.0021-0.0025. The optical loss for EFPAESO was less than 0.37 dB/cm at 1550 nm wavelength.     

Synthesis, characterization, and crosslinking of soluble cyano-containing poly(arylene ether)s bearing phthalazinone moiety

A novel series of phthalazinone-based poly(arylene ether nitrile)s bearing terminal cyano groups via N-C linkages (PPEN-DCs) were synthesized by a simple solution polycondensation of 4-(4-hydroxylphenyl)(2H)-phthalazin-1-one (HPPZ) with calculated 2,6-difluorobenzonitrile (DFBN), followed by the termination of 4-chlorobenzonitrile (CBN). The M_ns of oligomeric PPEN-DCs, which are in the range of 1600-6200, can be well-controlled by adjusting reactant ratio. The incorporation of phthalazinone into the polymer chain results in an improvement in the solubility and glass transition temperatures (T_gs). The amorphous PPEN-DCs were thermally crosslinked to afford insoluble products in the presence of terephthalonitrile and zinc chloride. The pendant cyano groups in the polymer chain hardly undergo any crosslinking or cyclization, while the terminal cyano groups with nitrogen-bridged phthalazinone in the para-substitution are much more reactive in s-triazine forming reaction and effectively promote certain crosslinking under normal pressure. T_gs of the oligomers, which range from 245 to 269 °C, could be further increased at least by 94 °C upon thermal curing. The crosslinked samples exhibit excellent thermal stability and absorb less than 2.7 wt% water after exposure to an aqueous environment for extended periods. This kind of cyano-terminated poly(arylene ether nitrile)s may be a good candidate as matrix resins for high-performance polymeric materials.     

Synthesis and properties of novel fluorinated poly(arylene ether)s

Dibromomethylene‐containing monomer with a tetrafluorobenzene central unit was synthesized using 2,3,5,6‐tetrafluoro‐1,4‐bis(4‐methylphenoxy)benzene as a starting material. This approach enabled preparation of several fluorinated poly(arylene ether)s containing isomeric fragments, with or without allyl or acetyl side groups, which were prepared by interaction of the synthesized tetrafluorobenzene‐based monomer with various types of hydroxyl‐substituted diphenyl ethers. The structure of the synthesized compounds was determined using Fourier transform infrared, ¹H NMR and ¹⁹ F NMR spectroscopy techniques. Most of the resulting polyethers were soluble in chlorinated, ether‐type or polar amide solvents. The molecular weight, mechanical and thermal properties of the synthesized fluorinated poly(arylene ether)s were studied depending on the inherent isomery of macromolecular chains and the nature of functional groups. Some ways of functionalization of the prepared fluorinated polyethers with epoxy and triethoxysilyl groups were proposed. © 2015 Society of Chemical Industry     

Well-defined multi-stimuli responsive fluorinated graft poly(ether amine)s (fgPEAs)

Well-defined multi-stimuli responsive fluorinated graft poly(ether amine)s (fgPEAs) were synthesized through nucleophilic substitution/ring-opening reaction of commercial poly(propylene glycol) diglycidyl ether and Jeffamine L100, followed by functionalization of hydroxyl groups in backbone by fluorinated alkyl carboxylic acid. fgPEAs are comprised of hydrophilic short poly(ethylene oxide) (PEO) and hydrophobic fluorinated alkyl chains, which are grafted on poly(propylene oxide) (PPO) backbone alternately to form well-defined structure. In aqueous solution, fgPEA11 and fgPEA12 self-assembled into multi-dispersed micelles, while fgPEA13 formed the uniform-sized micro-micelles with diameter of about 200 nm. These obtained micelles from fgPEAs were multi-responsive to temperature, pH and ionic strength with tunable cloud point (CP). It’s notable that CP of fgPEAs aqueous solution increased with the increasing amount of graft fluorinated alkyl chains.     

Processable high Tg high strength fluorinated new poly(arylene ether)s containing imido aryl group

A series of poly(arylene ether)s ( 7a–7f ) were successfully synthesized by aromatic nucleophilic substitution reactions of imidoaryl biphenol (5), 4,9‐bis‐(4‐hydroxy‐phenyl)‐2‐phenyl‐benzo[f]isoindole‐1,3‐dione with six different trifluoromethyl substituted bisfluoro monomers ( 6a–6f ). The weight‐average molar masses of the polymers were up to 280 kD as measured by GPC. These poly(arylene ether)s exhibited glass transition temperatures up to 361°C in DSC. These polymers showed very high thermal stability up to 558°C for 10% weight loss under synthetic air in TGA. Except 7d–7f, remaining polymers 7a–7c were soluble in a wide range of organic solvents. Transparent thin films of these polymers cast from DCM or NMP exhibited tensile strengths up to 75 MPa and elongation at break up to 41% depending on their exact repeating unit structures. These poly(arylene ether)s showed cut‐off wavelength in between 400 and 450 nm except 7d and water absorption were in the range of 0.4 to 0.6%. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of organo‐soluble poly(ether ether ketone)s and poly(ether ether ketone ketone)s containing pendant pentadecyl chains

Poly(ether ether ketone)s and poly(ether ether ketone ketone)s containing pendant pentadecyl chains were synthesized by polycondensation of each of the two bisphenol monomers viz, 1,1,1‐[bis(4‐hydroxyphenyl)‐4′‐pentadecylphenyl]ethane and 1,1‐bis(4‐hydroxyphenyl)‐3‐pentadecyl cyclohexane with activated aromatic dihalides namely, 4,4′‐difluorobenzophenone, and 1,3‐bis(4‐fluorobenzoyl)benzene in a solvent mixture of N,N‐dimethylacetamide and toluene, in the presence of anhydrous potassium carbonate. Polymers were isolated as white fibrous materials with inherent viscosities and number average molecular weights in the range 0.70–1.27 dL g^?1 and 76,620–1,36,720, respectively. Poly(ether ether ketone)s and poly(ether ether ketone ketone)s were found to be soluble at room temperature in organic solvents such as chloroform, dichloromethane, tetrahydrofuran, and pyridine and could be cast into tough, transparent, and flexible films from their solutions in chloroform. Wide angle X‐ray diffraction patterns exhibited a broad halo at around 2θ = ～ 19° indicating that the polymers containing pentadecyl chains were amorphous in nature. In the small‐angle region, diffuse reflections of a typically layered structures resulting from the packing of pentadecyl side chains were observed. The temperature at 10% weight loss, obtained from TG curves, for poly(ether ether ketone)s and poly(ether ether ketone ketone)s were in the range 416–459°C, indicating their good thermal stability. A substantial drop in glass transition temperatures (68–78°C) was observed for poly(ether ether ketone)s and poly(ether ether ketone ketone)s due to “internal plasticization” effect of flexible pendant pentadecyl chains. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of novel (sulfonated) poly(arylene ether)s with pendent trifluoromethyl groups

This paper reports the synthesis of four different trifluoromethyl-substituted poly(arylene ether)s on the basis of 2,2-bis(4-hydroxyphenyl)hexafluoropropane (bisphenol AF) and various difluoro- or dinitrobiphenyl or terphenyl monomers in the course of a step-growth polycondensation. Besides a comparison between the polymerisability of the different monomer combinations, a main focus of this work lies on the NMR characterization of these poly(arylene ether)s. Poly(arylene ether)s with sufficiently high number average molecular weights were sulfonated by fuming sulfuric acid or chlorosulfonic acid and investigated in terms of membrane properties relevant for fuel cell applications.     

Soluble and crosslinkable poly(phthalazinone ether ketone)s with pendent terminal ethynyl groups: synthesis,characterization and click modification

New poly(phthalazinone ether ketone)s (PPEKs) with pendent terminal ethynyl groups were synthesized by the aromatic nucleophilic substitution (S_NAr) polycondensation reaction of a new bisphenol monomer, 2‐(3‐ethynylphenyl)hydroquinone, with 4‐(4′‐hydroxyphenyl)phthalazin‐1(2H)‐one and 4,4′‐bis(4‐fluorophenyl) ketone, followed by click modification reaction with 1‐azidopyrene. Fourier transform infrared and NMR spectral data of the model compound indicated that the terminal ethynyl groups were stable in S_NAr reaction conditions, thus allowing the synthesis of the desired polymers. The PPEKs obtained with glass transition temperature (T_g) in the range 152–245 °C were amorphous, characterized by wide‐angle X‐ray diffraction, and dissolved in organic solvent to cast into transparent and flexible films. Differential scanning calorimetry results indicated that the curing reaction of the terminal ethynyl groups of the copolymers took place upon heating to 250 °C. The T_g of cured PPEKs was increased to about 260 °C. They also exhibited excellent thermal stability with 5% weight loss temperatures ranging from 448 to 527 °C in various atmospheres. The PPEKs with pendent terminal ethynyl groups were subsequently functionalized with pyrene through click reaction. A dilute chloroform solution displayed a red‐shifted emission profile. © 2014 Society of Chemical Industry     

Synthesis and characterization of soluble copoly(arylene ether sulfone phenyl-s-triazine)s containing phthalazinone moieties in the main chain

A series of new poly(arylene ether sulfone phenyl-s-triazine) copolymers containing phthalazinone moieties in the main chain (PPESPs) were prepared by a direct solution polycondensation of 4-(4-hydroxylphenyl)(2H)-phthalazin-1-one (HPPZ) with 2-phenyl-4,6-bi(4-fluorophenyl)-1,3,5-triazine (BFPT) and 4,4′-dichlorodiphenyl sulfone (DCS). Model reactions monitored by HPLC indicated that BFPT had slightly higher reactivity than DCS in nucleophilic displacement reactions. The obtained random copolymers were characterized by FTIR, NMR, elemental analysis and GPC. The presence of sulfone and phthalazinone in the polymer chain results in an improvement in the solubility of poly(arylene ether phenyl-s-triazine)s in common organic solvents, such as N-methylpyrrolidone, N,N-dimethyl acetamide (DMAc), chloroform, sulfolane and pyridine. Thermal analysis reveal that the copolymers exhibit high glass transition temperatures (T_gs) ranging from 271–300 °C, and excellent thermal stability associated with decomposition temperatures for 5% mass-loss exceeding 503 °C. All copolymers are amorphous except PPESP28 as evidenced by WAXD. Their T_gs and solubility increase with an increase in sulfone content in the polymer backbone, while the crystallinity and overall thermal stability appear to decrease. This kind of phthalazinone-based copoly(arylene ether sulfone phenyl-s-triazine)s may be considered a good candidate for using as high-performance structural materials.     

Cross-linkable highly halogenated poly(arylene ether ketone/sulfone)s with tunable refractive index: Synthesis, characterization and optical properties

A series of novel cross-linkable, highly halogenated poly(arylene ether ketone)s (HPAEKs) and poly(arylene ether sulfone)s (HPAESs) with different bromine contents have been designed and prepared by polycondensation reactions for use as optical waveguide materials. The method used for their preparation involved reacting decafluorodiphenyl ketone/sulfone (DFPK/DFPS) with a mixture of 4,4′-isopropylidene bis(2,6-dibromophenol) (4Br-BPA), 4,4′-(hexafluoroisopropylidene)diphenol (6F-BPA), and 1,1-bis(4-hydroxyphenyl)ethyl-1-phenyl-2,3,5,6-tetrafluorostyrol ether (BHPFS). The feed ratio of 4Br-BPA to the total bisphenols varied from 0 to 80 mol.%, while that of BHPFS remained at 20% for all polymers. The resulting polymers have excellent solubility in most common organic solvents such as tetrahydrofuran, cyclohexanone and N,N-dimethylacetamide (DMAc) and can be easily cast into optical-quality thin films. A high glass transition temperature in the range of 164-206 °C was found for these polymers, which could be further increased by about 20 °C upon thermal or photochemical cross-linking. Slab and channel waveguides have been prepared from these polymers. All of them exhibited low optical loss (0.4-0.6 dB/cm) at the telecommunication wavelength of 1550 nm. Due to the relatively higher polarizability of the C-Br bond than that of the C-H bond, an increase in the refractive index was observed as the bromine content in the polymers increased. Consequently, the refractive index of HPAEKs and HPAESs can be readily adjusted within a wide range from 1.51 to 1.57 by simply changing the ratio of the bromine-containing bisphenol in the feed. This variability, along with the excellent cross-linking capability, allows these polymers to be used as both the core and the cladding materials for the waveguide device fabrication and provides a greater flexibility in the design of device structures.     

New poly(arylene ether)s containing phthalimidine group in the main chain

Five new poly(arylene ether)s containing phthalimidine group in the main chain and pendent trifluoromethyl group have been prepared by the reaction of 4,4′‐(bis‐4‐fluoro‐3‐trifluoromethylphenyl)benzene (BTF) with bisphenols. Different molar ratios of N‐phenyl‐3,3‐bis(4‐hydroxyphenyl)phthalimidine (PA) and 4,4′‐isopropylidenediphenol (BPA) have been used to generate different copolymers. The polymers obtained by step growth polymerization exhibited weight‐average molecular weight upto 134,000 g/mol with a polydispersity index of 2.1–2.4. The homopolymer from BTF and PA showed very high glass transition temperature of 258°C and outstanding thermal stability upto 536°C for 5% weight loss under nitrogen. The polymers were soluble in a wide range of organic solvents. Transparent thin films of these polymers exhibited tensile strengths upto 65 MPa and elongation at break upto 45% depending on the exact repeat unit structures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of a novel phthalazinone poly(aryl ether sulfone ketone) with carboxyl group

Soluble, thermally stable phthalazinone poly(aryl ether sulfone ketone)s (PPESKs) containing a carboxyl group in its side chain have been synthesized by the nucleophilic displacement reaction of 4‐(4‐hydroxylphenyl)‐1(2H)‐phthalazinone with bis(4‐chlorophenyl) sulfone, 4,4′‐difluoro‐benzophenone, and phenolphthalin. The polymerization reactions were conducted in sulfolane in the presence of K₂CO₃ to give high molecular weight polymers, which are soluble in solvent such as nitrobenzene and pyridine at room temperature and easily cast into flexible, yellow, and transparent film. The polymers are amorphous with high glass transition temperature. The decomposition temperature of the polymers are >400°C, which indicates high thermal stability. The crosslinking reaction of PPESK can occur by using dicyandiamide (Dicy) as curing agent. The apparent energy (ΔE) is 52.2 kJ/mol and reaction order (n) is close to 1.0. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1111–1114, 2003     

Fine poly(ether ether ketone) powders

The physical form of polymers is often important for carrying out subsequent processing operations. For example, fine powders are desirable for molding and sintering compounds because they consolidate to produce void free components. The objective of this work is to prepare fine polymeric particulates suitable for processing into fiber reinforced polymer matrix composites. Micron size particles of poly(ether ether ketone) (PEEK) were prepared by rapidly quenching solutions of these materials. PEEK pellets were dissolved at temperatures near the PEEK melting point in a mixture of terphenyls and quaterphenyls; then the solution was quenched to a temperature between the T_g and T_m (≈ 225°C) by adding a room temperature eutectic mixture of diphenyl ether and biphenyl. A supersaturated, metastable solution of PEEK resulted, causing rapid nucleation. Fine PEEK particles rapidly crystallized from this solution. The average particle size was measured using transmission electron microscopy, atomic force microscopy, and by light scattering of aqueous suspensions which had been fractionated by centrifugation. The average particle diameter was about 0.6 μm. Three dimensional photomicrographs obtained via atomic force microscopy showed some aggregates in the suspensions. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1571–1578, 1997     

Preparation and performance of crosslinked poly(arylene ether)s containing azobenzene chromophores

A series of novel poly(arylene ether)s with crosslinked groups and different azobenzene chromophores contents (azo-CPAEs: PAE-allyl20%-azo20%, PAE-allyl20%-azo40%, PAE-allyl20%-azo60%) were synthesized from a new bisfluoro monomer, (2,6-difluorophenyl)-(4-hydroxyphenyl)methanone. Their chemical structures were characterized by means of UV-vis and FI-IR. The thermal properties of the polymers were investigated by TGA and DSC, indicating the polymers had high glass transition temperatures (T_g > 147 °C) and good thermal stability (T_d5 > 360 °C) even when the contents of azobenzene chromophores was high to 60%. And the influence of thermal crosslinking on the performance of PAE-allyl20%-azo20%, a typical one of the series, was investigated. T_g of PAE-allyl20%-azo20% increased with the increase of heating time when heat-treated at 250 °C for 20, 40 and 60 min, indicating the crosslink degree of the polymer increased. After heat-treated for 60 min, T_g of PAE-allyl20%-azo20% increased to 175 °C from 147 °C before thermal crosslinking. Upon irradiation with a 532 nm neodymium doped yttrium aluminum garnet (Nd:YAG) laser beam, the remnant value of the polymer PAE-allyl20%-azo20% before and after the thermal crosslinking were 81 and 96%, respectively, meaning that the PAE-allyl20%-azo20% after thermal crosslink showed more stable photoinduced alignment than that before thermal crosslinking.     

Synthesis of sulfonated poly(phthalazinone ether sulfone)s by direct polymerization

Sulfonated poly(phthalazinone ether sulfone)s with high molecular weight were directly prepared by polycondensation of 4-(4-hydroxyphenyl) phthalazinone with various ratios of disodium 5.5′-sulfonylbis(2-fluoro-benzenesulfonate) to 4-fluorophenyl sulfone. The resulting ionomers with high IEC showed low swelling. The low swelling originates from intermolecular hydrogen bonds, which is confirmed by variable temperature IR spectroscopy. The membranes show very good perspectives in PEMFC applications.     

Preparation and evaluation of sulfonated-fluorinated poly(arylene ether)s membranes for a proton exchange membrane fuel cell (PEMFC)

New proton exchange membranes were prepared and evaluated as polymer electrolytes for a proton exchange membrane fuel cell (PEMFC). Two types of fluorinated poly(arylene ether)s (FPAEs) were synthesized by nucleophilic aromatic substitution of decafluorobiphenyl (DFBP) with 4,4′-(hexafluoroisopropylidene)diphenol (HFDP) and bisphenol-A (BPA). The FPAEs so prepared were converted into proton exchange polymers by sulfonation with fuming sulfuric acid (30% SO₃). The FPAEs and sulfonated-fluorinated poly(arylene ether)s (S-FPAEs) with various sulfonation levels were characterized using NMR, thermogravimetric analysis (TGA) and back titration, and then successfully evaluated as proton exchange membranes (PEM) with unit cell operation. power output measurements of S-DFBP-HFDP carried out at a cell temperature of 80 °C. They exhibited a maximum power density of 425.5 mW/cm² at 1150 mA/cm².     

Synthesis and characterization of fluorinated poly(azomethine ether)s from new core-fluorinated azomethine-containing monomers

In this work, we describe the design and synthesis of novel core-fluorinated Schiff base monomers and conjugated polymers based on them. The new fully aromatic highly fluorinated poly(azomethine ether)s (PAMEs) were prepared by polycondensation of core-fluorinated azomethine-containing compounds. The structure of the monomers and polymers were confirmed by FTIR, ¹H, ¹³C, and ¹⁹F NMR spectroscopic analysis. The influence of synthesis condition on the properties of PAME compounds was investigated. Application of polarization microscopy with a temperature control thermal stage revealed thermotropic liquid crystalline (LC) behavior in the synthesized materials. Transition temperatures and a range of the existence of the LC phase were studied by a combination of the optical microscopy and DSC analysis. According to the TGA analysis, all the synthesized PAMEs show high thermal stability and thus offer a wide range of thermal processibility (up to 410–477 °C), which makes them prospective materials for many modern applications.