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     

Polyimides 6: Synthesis,characterization, and comparison of properties of novel fluorinated poly(ether imides)

Five new poly(ether imides) have been prepared on reaction with oxydiphthalic anhydride (ODA) with five different diamines: 1,4‐bis(p‐aminophenoxy‐2′‐trifluoromethyl benzyl) benzene, 4,4′‐bis(p‐aminophenoxy‐2′‐trifluoromethyl benzyl) benzene, 1,3‐bis(p‐aminophenoxy‐2′‐trifluoromethyl benzyl) benzene, 2,6‐bis(p‐aminophenoxy‐2′‐trifluoromethyl benzyl) pyridine, and 2,5‐bis(p‐aminophenoxy‐2′‐trifluoromethyl benzyl) thiophene. Synthesized polymers showed good solubility in different organic solvents. The polyimide films have low water absorption of 0.3–0.7%, low dielectric constants of 2.82–3.19 at 1 MHz, and high optical transparency at 500 nm (>73%). These polyimides showed very high thermal stability with decomposition temperatures (5% weight loss) up to 531°C in air and good isothermal stability; only 0.4% weight loss occurred at 315°C after 5 h. Transparent thin films of these polyimides exhibited tensile strength up to 147 MPa, a modulus of elasticity up to 2.51 GPa and elongation at break up to 30% depending upon the repeating unit structure. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 821–832, 2004     

Hydroquinone Based Sulfonated Copolytriazoles with Enhanced Proton Conductivity

A series of new fluorinated sulfonated copolytriazoles (PTHQSH‐XX) with ion exchange capacity (IEC_w) values ranging from 1.66 to 2.82 meq g⁻¹ are prepared via cuprous ion catalyzed azide‐alkyne click polymerization reaction between 1,4‐bis(prop‐2‐ynyloxy)benzene, 4,4′‐diazido‐2,2′‐stilbene disulfonic acid disodium salt (SA), and 4,4‐bis[3′‐trifluoromethyl‐4′(4‐azidobenzoxy) benzyl] biphenyl (QAZ). The degree of sulfonation of the copolytriazoles is adjusted between 60% and 90% by varying the molar ratio of sulfonated monomer (SA) to the nonsulfonated monomer (QAZ). The structure of the copolytriazoles is characterized by Fourier transform infrared and NMR spectroscopy. The solution‐cast membranes of these copolymers exhibit high thermal, mechanical, oxidative and hydrolytic stability, and high proton conductivity (19–142 mS cm⁻¹ at 80 °C and 22–157 mS cm⁻¹ at 90 °C). Transmission electron microscopy confirms the formation of good phase separated morphology with ionic clusters in the range of 15–145 nm.     

Synthesis,characterization and investigation of proton exchange properties of sulfonated polytriazoles from a new semifluorinated diazide monomer

This work describes the synthesis and characterization of a new series of semifluorinated sulfonated polytriazole copolymers (PTATSH‐XX) with varying degree of sulfonation and higher IEC. The copolymers have been prepared by click reaction using a combination of diazide monomers; a newly synthesized diazide monomer namely 4,4‐bis[3‐trifluoromethyl‐4(4‐azidophenoxy)phenyl]benzene (TAZ) and a commercially available diazide monomer namely 4,4′‐diazido‐2,2′‐stilbenedisulfonic acid disodium salt (DADSDB) with a bis‐alkyne monomer namely 4,4′‐(propane‐2,2‐diyl)bis((prop‐2‐ynyloxy)benzene) (BPEBPA). The copolymers are well characterized by FTIR and NMR spectroscopy and have exhibited good solubility and film forming abilities along with good thermal and chemical stability, low water uptake, good dimensional stability and high mechanical properties. The TEM micrographs of the copolymer membranes show good phase separated morphology with cluster size in the range 10–60 nm. The proton conductivity values of the copolymer membranes are found in the range of 15–90 mS cm^?1 at 80°C and 16–97 mS cm^?1 at 90°C. POLYM. ENG. SCI., 57:312–323, 2017. © 2016 Society of Plastics Engineers     

Synthesis and characterization of chemically stable sulfonated copoly(triazole imide)s with high proton conductivity

The synthesis and characterization of a series of new sulfonated copoly(triazole imide)s (PTPQSH‐XX) are reported in this work. The PTPQSH‐XX with different degree of sulfonation (DS) were prepared by click polymerization of equimolar amounts of a diimide‐based dialkyne monomer, namely bis‐N,N′‐(prop‐2‐ynyl)pyromellitic diimide (TP) and a mixture of two different diazide monomers (one sulfonated, 4,4‐bis[3′‐trifluoromethyl‐4′{4‐azidobenzoxy} benzyl] biphenyl, and another nonsulfonated, 4,4′‐diazido‐2,2′‐stilbene disulfonic acid disodium salt [SAZ]), in different molar ratios. The copolymers showed high inherent viscosity (1.12–1.28 dL/g) in n‐methyl pyrrolidone (NMP) indicating the formation of high molar masses. Freestanding membranes were prepared from these copolymers by solution casting method. DS of the copolymers was determined from ¹H NMR signal intensities, and the values were in good agreement with the quantity of SAZ monomer used in polymer feed, indicating the successful incorporation of the sulfonated monomer. The copolymers exhibited high thermal and mechanical stabilities. The PTPQSH‐80 membrane showed proton conductivity as high as 178 mS/cm at 90°C with good oxidative and hydrolytic stability. Cross‐sectional transmission electron microscope micrographs of the membranes indicated phase segregated morphology along with interconnected hydrophilic domains with dimension in the range 15–150 nm. POLYM. ENG. SCI., 59:2279–2289, 2019. © 2019 Society of Plastics Engineers     

Synthesis,characterization, and comparison of properties of novel fluorinated poly(imide siloxane) copolymers

Four new poly(imide siloxane) copolymers were prepared by a one‐pot solution imidization method at a reaction temperature of 180°C in ortho‐dichlorobenzene as a solvent. The polymers were made through the reaction of o‐diphthaleic anhydride with four different diamines—4,4′‐bis(p‐aminophenoxy‐3,3″‐trifluoromethyl) terphenyl, 4,4′‐bis(3″‐trifluoromethyl‐p‐aminobiphenyl ether)biphenyl, 2,6‐bis(3′‐trifluoromethyl‐p‐aminobiphenyl ether)pyridine, and 2,5‐bis(3′‐trifluoromethyl‐p‐aminobiphenylether)thiopene—and aminopropyl‐terminated poly dimethylsiloxane as a comonomer. The polymers were named 1a , 1b , 1c , and 1d , respectively. The synthesized polymers showed good solubility in different organic solvents. The resulting polymers were well characterized with gel permeation chromatography, IR, and NMR techniques. ¹H‐NMR indicated that the siloxane loading was about 36%, although 40 wt % was attempted. ²⁹Si‐NMR confirmed that the low siloxane incorporation was due to a disproportionation reaction of the siloxane chain that resulted in a lowering of the siloxane block length. The films of these polymers showed low water absorption of 0.02% and a low dielectric constant of 2.38 at 1 MHz. These polyimides showed good thermal stability with decomposition temperatures (5% weight loss) up to 460°C in nitrogen. Transparent, thin films of these poly(imide siloxane)s exhibited tensile strengths up to 30 MPa and elongations at break up to 103%, which depended on the structure of the repeating unit. The rheological properties showed ease of processability for these polymers with no change in the melt viscosity with the temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and characterization of thermotropic liquid crystalline poly(aryl ether ketone) copolymers with pendant 3‐(trifluoromethyl) phenyl groups

Novel poly(aryl ether ketone) copolymers with pendant 3‐(trifluoromethyl)phenyl groups were synthesized by the reaction of a crystal‐disrupting monomer, 3‐(trifluoromethyl)phenylhydroquinone (FH) and a mesogenic monomer, 4,4′‐biphenol (BP) with 1,4‐bis(p‐fluorobenzoyl)benzene (BF). Thermotropic liquid crystalline behavior of the copolymers was investigated by means of differential scanning calorimetry, polarized optical microscope and wide‐angle X‐ray diffraction. As a result, the copolymers with the respective molar ratios of FH/BP/BF of 0/100/100–10/90/100 and 80/20/100–100/0/100 were semi‐crystalline without liquid crystalline properties, and amorphous polymers, respectively. In contrast, copolymers with the molar ratio of FH/BP/BF of 20/80/100–70/30/100 had liquid crystalline characteristics. Interestingly, the formation of a highly ordered smectic phase was confirmed for copolymers with the molar ratio of FH/BP/BF of 20/80/100–50/50/100, respectively. All the liquid crystalline copolymers had a wide liquid crystalline temperature range (57–75 °C). Copyright © 2006 Society of Chemical Industry     

Synthesis and characterization of soluble poly(ether imide)s containing fluorenyl cardo groups

Two series of poly(ether imide)s (PEIs) containing fluorenyl cardo groups in the main chains were synthesized, which are derived from the polycondensation of 9,9′‐bis(4‐aminophenoxyphenyl)fluorene (BAOFL) or 9,9′‐bis(3‐trifluoromethyl,4‐aminophenoxyphenyl)fluorene (6F‐BAOFL) with four kinds of dianhydrides (3,3′,4,4′‐biphenyltetracarboxylic dianhydride, 4,4′‐oxydiphthalicanhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride, and bisphenol‐A dianhydride), respectively. The PEI films and PEI powder were prepared by thermal and chemical imidization, respectively. The PEIs were characterized by FTIR, ¹H‐NMR, differential scanning calorimetry, thermogravimetric analysis, and UV–vis were performed on inherent viscosity, solubility, and tensile tests. The effects of fluorenyl cardo groups and ether linkages on the solubility, tensile properties, thermal stability, and optical properties were investigated in detail. It was found that the PEIs had good solubility in common organic solvents and good optical transparency in visible light region. In addition, the PEI films exhibited excellent tensile and thermal properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and characterization of soluble copoly(aryl ether ketone)s containing hindering structures

New copoly(aryl ether ketone)s have been synthesized by polycondensation of 2,2′,3,3′,6,6′‐hexaphenyl‐4,4′‐diphenol, 2,2′‐p‐hydroxyphenyl‐iso‐propane, and 4,4′‐difluorobenzophenone. The technology of ¹³C‐NMR was used to determine contents of the two bisphenols in the copolymers. Chain structure was characterized by illustrating average block length (L_A, L_C) in terms of portion of the triads (AKA, CKC, AKC). The obtained copoly(aryl ether ketone)s have the properties of excellent solubility, high heat‐resistance, good tensile strength, and good selectivity for gas permeability. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 20–24, 2000     

Synthesis and characterization of novel poly(arylene ether)s based on 9,10‐bis‐(4‐fluoro‐3‐trifluoromethylphenyl) anthracene and 2,7‐bis‐(4‐fluoro‐3‐trifluoromethylphenyl) fluorene

Two new bisfluoro monomers 9,10‐bis‐(4‐fluoro‐3‐trifluoromethylphenyl) anthracene and 2,7‐bis‐(4‐fluoro‐3‐trifluoromethylphenyl) fluorene have been synthesized by the cross‐coupling reaction of 2‐fluoro‐3‐trifluoromethyl phenyl boronic acid with 9,10‐dibromo anthracene and 2,7‐dibromo fluorine, respectively. These two bisfluoro compounds were used to prepare several poly(arylene ether)s by aromatic nucleophilic displacement of fluorine with various bisphenols; such as bisphenol‐A, bisphenol‐6F, bishydroxy biphenyl, and 9,9‐bis‐(4‐hydroxyphenyl)‐fluorene. The products obtained by displacement of the fluorine atoms exhibits weight‐average molar masses up to 1.5 ×10⁵ g mol^?1 and number average molecular weight up to 6.8 × 10⁴ g mol^?1 in GPC. These poly(arylene ether)s show very high thermal stability even up to 490°C for 5% weight loss occurring at this temperature in TGA in synthetic air and showed glass transition temperature observed up to 310°C. All the polymers are soluble in a wide range of organic solvents, e.g., CHCl₃, THF, NMP, and DMF. Films cast from DMF solution are brittle in nature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Synthesis,characterization, and acoustic properties of new soluble polyurethanes based on 2,2′‐[1,4‐phenylenebis(nitrilomethylylidene)diphenol and 2,2′‐[4,4′‐methylene‐di‐2‐methylphenylene‐1,1′‐bis(nitrilomethylylidene)]diphenol

Eight novel polyurethanes based on 2,2′‐[1,4‐phenylenebis(nitrilomethylylidene)]diphenol and 2,2′‐[4,4′‐methylene‐di‐2‐methylphenylene‐1,1′‐bis(nitrilomethylylidene)]diphenol acting as hard segments with two aromatic and two aliphatic diisocyanates (4,4′‐diphenylmethane diisocyanate, toluene 2,4‐diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate) were prepared and characterized with Fourier transform infrared, UV spectrophotometry, fluorescence spectroscopy, ¹H‐NMR and ¹³C‐NMR spectroscopy, thermogravimetric analysis, and differential thermal analysis. All the polyurethanes contained domains of semicrystalline and amorphous structures, as indicated by X‐ray diffraction. The acoustic properties and solubility parameters were calculated with the group contribution method. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis and Characterization of Sulfonated Cardo Poly(Arylene Ether Sulfone)s for Fuel Cell Proton Exchange Membrane Application

Sulfonated cardo poly(arylene ether sulfone)s ( SPPA ‐ PES ) with various degrees of sulfonation (DS) were prepared by post‐sulfonation of synthesized phenolphthalein anilide ( PPA ; N‐phenyl‐3,3′‐bis(4‐hydroxyphenyl)‐1‐isobenzopyrolidone) poly(arylene ether sulfone)s ( PPA ‐ PES ) by using concentrated sulfuric acid. PPA ‐ PES copolymers were synthesized by direct polycondensation of PPA with bis‐(4‐fluorophenyl)‐sulfone and 4,4′‐sulfonyldiphenol. The DS was varied with different mole ratios of PPA (24, 30, 40, 50 mol.%) in the polymer. The structure of the resulting SPPA ‐ PES copolymers and the different contents of the sulfonated unit were studied by Fourier transform infrared (FT‐IR) spectroscopy, ¹H NMR spectroscopy, and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity of SPPA ‐ PES were evaluated according to the increase of DS. The water uptake (WU) of the resulting SPPA ‐ PES membranes was in the range of 20–72%, compared with 28% for Nafion 211®. The SPPA ‐ PES membranes showed proton conductivities of 23–82 mS cm^–1, compared with 194 mS cm^–1 for Nafion 211®, under 100% relative humidity (RH) at 80 °C.     

Synthesis and thermotropic liquid‐crystalline behavior of novel main‐chain poly(aryl ether ketones)

Novel aromatic poly(ether ketones) containing bulky lateral groups were synthesized via nucleophilic substitution reactions of 4,4′‐biphenol and (4‐chloro‐3‐trifluoromethyl)phenylhydroquinone (CF‐PH) with 1,4‐bis(p‐fluorobenzoyl)benzene. The copolymers were characterized by differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction, and polarized light microscopy observation. Thermotropic liquid‐crystalline behavior was observed in the copolymers containing 40, 50, 60, and 70 mol % CF‐PH. The crystalline–liquid‐crystalline transition [melting temperature (T_m)] and the liquid‐crystalline–isotropic phase transition appeared in the DSC thermograms, whereas the biphenol‐based homopolymer had only a melting transition. The novel poly(aryl ether ketones) had glass‐transition temperatures that ranged from 143 to 151°C and lower T_m's that ranged from 279 to 291°C, due to the copolymerization. The polymers showed high thermal stability, and some exhibited a large range in mesophase stability. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1347–1350, 2003     

Synthesis and properties of fluoro‐polyetherimides

A series of amorphous fluoro‐polyetherimides based on 2,2′‐bis(3,4‐dicarboxyphenyl) hexafluropropane dianhydride (6FDA) and di‐ether‐containing diamines 4,4′‐bis(3‐aminophenoxy)diphenyl sulfone (m‐SED), 4,4′‐bis(4‐aminophenoxy)diphenyl sulfone (p‐SED), 4,4′‐bis(4‐aminophenoxy)diphenyl propane (BPADE) were synthesized. These melt processable polyetherimide polymers from p‐SED and BPADE showed excellent electrical properties. The dielectric constants, 2.74 and 2.65 at 10 MHz respectively, are lower than commercially available polyetherimide ULTEM® 1000, and polyimide Kapton® H films. In addition, we found that trifluoromethyl groups‐containing polyimides not only show extraordinary electrical properties, but they also exhibit excellent long‐term thermo‐oxidative stability and reduced water absorption relative to non‐fluorinated polyimides. The weight retention of these fluoro‐polyetherimides at 315°C for 300 h in air varies from 93% to 98%. Whereas, their moisture absorption at 100 RH at 50°C was in the range of 0.3% to 1.05%, which is much lower than those of Ultem 1000 and Kapton H. In the case of fluoro‐polyetherimides from p‐SED and m‐SED (para and meta isomers) diamines with ‘ether’ and sulfonyl (‐SO₂‐) spacer groups, the d‐spacing and T_g values decreased from 4.72Å to 4.56Å and 293°C to 244°C respectively. Similarly, the transparency of these polymer films (in the range of 80% to 90%) at 500 nm solar wavelength was higher than Ultem 1000 and Kapton H.     

Novel sulfonated poly(arylene biphenylsulfone ether) copolymers containing bisphenylsulfonyl biphenyl moiety: structural,thermal, electrochemical and morphological characteristics

A series of sulfonated poly(arylene biphenylsulfone ether) polymers containing up to two pendant sulfonic acid groups per repeat unit were successfully synthesized from 4,4′‐bis[(4‐chlorophenyl)sulfonyl]‐1,1′‐biphenyl (BCPSBP), disodium 3,3′‐disulfonate‐4,4′‐dichlorodiphenylsulfone (SDCDPS) and bisphenol A via aromatic nucleophilic displacement polycondensation. The resulting polymers were characterized by means of Fourier transform infrared and ¹H NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry and thermogravimetric analysis (TGA). The number‐average molecular weight (M_n) of the synthesized polymers was in the range 15 300–22 900 g mol^?1, and the polydispersity indices (M_w/M_n) varied from 2.5 to 4.4. Tough membranes with SDCDPS/BCPSBP mole ratio up to 50:50 were successfully cast using N‐methyl‐2‐pyrrolidone (NMP). An increase of sulfonic acid groups in the polymer backbone resulted in increased solubility in aprotic polar solvents and glass transition temperature. The TGA curves of all the copolymers in acid form exhibited two distinct weight‐loss profiles. The influential characteristics of the polymer electrolyte membranes, such as tensile strength, water uptake, ion‐exchange capacity and proton conductivity, were characterized with respect to the pendant sulfonic acid groups. Atomic force microscopy phase images of the acid‐form membranes clearly showed the hydrophilic domains, with sizes increasing as a function of the degree of sulfonation. Copyright © 2010 Society of Chemical Industry     

Synthesis and characterization of conducting poly(aniline‐co‐diaminodiphenylsulfone) copolymers

Polyaniline, poly(aniline‐co‐4,4′‐diaminodiphenylsulfone), and poly(4,4′‐diaminodiphenylsulfone) were synthesized by ammonium peroxydisulfate oxidation and characterized by a number of techniques, including infrared spectroscopy, ultraviolet–visible absorption spectroscopy, ¹H‐NMR, thermogravimetric analysis, and differential scanning calorimetry. These copolymers had enhanced solubility in common organic solvents in comparison with polyaniline. The conductivities of the HCl‐doped polymers ranged from 1 S cm^?1 for polyaniline to 10^?8 S cm^?1 for poly(4,4′‐diaminodiphenylsulfone). The copolymer compositions showed that block copolymers of 4,4′‐diaminodiphenylsulfone (r₁ > 1) and aniline (r₂ < 1) formed and that the reactivity of 4,4′‐diaminodiphenylsulfone was greater than that of aniline. The results were explained by the effect of the ? SO₂? group present in the polymer structure. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2337–2347, 2003     

Synthesis and properties of novel copolymers of poly(ether ketone diphenyl ketone ether ketone ketone) and poly(ether amide ether amide ether ketone ketone)

New monomers, 4,4′‐bis(4‐phenoxybenzoyl)diphenyl (BPOBDP) and N,N′‐bis(4‐phenoxybenzoyl)?4,4′‐diaminodiphenyl ether (BPBDAE), were conveniently synthesized via simple synthetic procedures from readily available materials. Novel copolymers of poly(ether ketone diphenyl ketone ether ketone ketone) (PEKDKEKK) and poly(ether amide ether amide ether ketone ketone) (PEAEAEKK) were synthesized by electrophilic Friedel‐Crafts solution copolycondensation of isophthaloyl chloride (IPC) with a mixture of BPOBDP and BPBDAE, over a wide range of BPOBDP/BPBDAE molar ratios, in the presence of anhydrous AlCl₃ and N‐methylpyrrolidone (NMP) in 1,2‐dichloroethane (DCE). The copolymers obtained were characterized by different physico‐chemical techniques. The copolymers with 10–40 mol% BPBDAE are semicrystalline and had remarkably increased T_gs over commercially available PEEK and PEKK due to the incorporation of amide and diphenyl linkages in the main chains. The copolymers IV and V with 30–40 mol% BPBDAE had not only high T_gs of 185–188°C, but also moderate T_ms of 326–330°C, having good potential for the melt processing. The copolymers IV and V had tensile strengths of 101.7–102.3 MPa, Young's moduli of 2.19–2.42 GPa, and elongations at break of 13.2–16.6% and exhibited high thermal stability and excellent resistance to organic solvents. POLYM. ENG. SCI., 54:1757–1764, 2014. © 2013 Society of Plastics Engineers     

Synthesis and properties of poly(aryl ether sulfone ether ketone ketone) (PESEKK)

4,4′‐bis(Phenoxy)diphenyl sulfone (DPODPS) was synthesized by reaction of phenol with bis(4‐chlorophenyl) sulfone in tetramethylene sulfone in the presence of NaOH. Two poly(aryl ether sulfone ether ketone ketone)s (PESKKs) with high molecular weight were prepared by low temperature solution polycondensation of DPODPS and terephthaloyl chloride (TPC) or isophthaloyl chloride (IPC), respectively, in 1,2‐dichloroethane and in the presence of aluminum chloride (AlCl₃) and N‐methylpyrrolidone (NMP). The resulting polymers were characterized by various analytical techniques, such as FT‐IR, ¹H‐NMR, DSC, TG, and WAXD. The results show that the T_g and T_d of PESEKKs are much higher, but its T_m is lower than those of PEKK. The other results indicate that PESEKKs exhibit excellent thermostabilities at 300 ± 10°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 489–493, 2005     

Synthesis of novel poly(ether ketone diphenyl ketone ether ketone ketone)s by electrophilic Friedel–Crafts solution polycondensation

4,4′‐Bis(4‐phenoxybenzoyl)diphenyl was prepared by the Friedel–Crafts reaction of 4‐bromobenzoyl chloride and diphenyl followed by condensation with potassium phenoxide. Novel aromatic poly(ether ketone diphenyl ketone ether ketone ketone)s were obtained by the electrophilic Friedel–Crafts solution copolycondensation of 4,4′‐bis(4‐phenoxybenzoyl)diphenyl with a mixture of isophthaloyl chloride and terephthaloyl chloride over a wide range of isophthaloyl chloride/terephthaloyl chloride molar ratios in the presence of anhydrous aluminum chloride and N‐methylpyrrolidone in 1,2‐dichloroethane. The influence of the reaction conditions on the preparation of the copolymers was examined. The copolymers were characterized with different physicochemical techniques. Because of the incorporation of diphenyl, the resulting copolymers exhibited outstanding thermal stability. The glass‐transition temperatures were above 174°C, the melting temperatures were above 342°C, and the 5% weight loss temperatures were above 544°C in nitrogen. All these copolymers were semicrystalline and insoluble in organic solvents. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and properties of poly(ester imide) copolymers from 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,2′-bis(trifluoromethyl)benzidine,and 4-aminophenyl-4′-aminobenzoate

A series of poly(ester imide) (PEsI) copolymers were synthesized using 3,3′,4,4′-biphenyltetracarboxylic dianhydride (4,4′-BPDA), 2,2′-bis(trifluoromethyl)benzidine (TFMB), and 4-aminophenyl-4′-aminobenzoate (APAB) as the monomers. Wide-angle x-ray diffraction results revealed that the average interchain distances of these polymers ranged from 4.6 to 5.7 Å, increasing with the increase of TFMB contents. PEsI-0.3 and PEsI-0.4 exhibited a glass transition temperature (T_g) of 445 and 455°C, respectively, while no distinctive T_g was observed for the PEsI copolymers when the APAB content was >50 mol%. The coefficients of thermal expansion (CTE) of these PEsI copolymers ranged from 3.8 to 24.2 ppm K⁻¹, increasing with the increase of TFMB contents. The PEsI copolymers exhibited a modulus of 5.7–7.8 GPa, a tensile strength of 282–332 MPa, and an elongation-at-break of 10.2%–23.3%. Furthermore, these copolymers exhibited a dielectric constant of 2.53–2.76, and a low dissipation factor (D_f) of 0.0026–0.0032 at 10 GHz in dry state. Because of their excellent combined properties, these PEsI copolymers are promising candidates as dielectric substrate materials for the applications in next generation flexible printed circuit boards operating at high frequencies.