Synthesis of copolymers of poly(ether sulfone ether ketone ketone) and poly(ether ketone diphenyl ketone ether ketone ketone) by electrophilic Friedel–Crafts solution polycondensation

A new monomer, 4,4′‐bis(4‐phenoxybenzoyl)diphenyl(BPOBDP), was synthesized via a two‐step synthetic procedure. A series of novel poly(ether sulfone ether ketone ketone)/poly(ether ketone diphenyl ketone ether ketone ketone) copolymers were prepared by electrophilic Friedel–Crafts solution copolycondensation of isophthaloyl chloride (IPC) with a mixture of 4,4′‐diphenoxydiphenylsulfone (DPODPS) and 4,4′‐bis(4‐phenoxybenzoyl)diphenyl (BPOBDP), in the presence of anhydrous aluminum chloride and N‐methylpyrrolidone (NMP) in 1,2‐dichloroethane (DCE). The copolymers with 10–50 mol% DPODPS are semicrystalline and have remarkably increased T_gs over commercially available PEEK and PEKK. The copolymers with 40–50 mol% DPODPS had not only high T_gs of 170–172°C, but also moderate T_ms of 326–333°C, which are extremely suitable for melt processing. These copolymers have tensile strengths of 96.5–108.1 MPa, Young's moduli of 1.98–3.05 GPa, and elongations at break of 13–26% and exhibit excellent thermal stability and good resistance to acidity, alkali, and common organic solvents. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and Characterization of Novel Organosoluble Methyl Substituted Poly(aryl Ether Ketone)s Containing Sulfone Linkage

Several new methyl substituted poly(aryl ether ketone)s containing sulfone linkage with inherent viscosities of 0.62–0.84 dL/g have been prepared from 4,4′‐bis(2‐methylphenoxy)diphenylsulfone and 4,4′‐bis(3‐methylphenoxy)diphenylsulfone with terephthaloyl chloride and isophthaloyl chloride by electrophilic Friedel‐Crafts acylation in the presence of DMF with anhydrous AlCl₃ as a catalyst in 1,2‐dichloroethane, respectively. These polymers having weight‐average molecular weight in the range of 71,000–49,000 are all amorphous and show high glass transition temperatures ranging from 167 °C to 191 °C, excellent thermal stability at temperatures over 400 °C in air or nitrogen, high char yields of 51–58% in nitrogen and good solubility in CHCl₃ and polar solvents such as DMF, DMSO and NMP at room temperature.     

Synthesis of aromatic poly(ether amide amide ether ketone ketone)s by electrophilic Friedel–Crafts solution polycondensation

A new monomer, N,N′‐bis(4‐phenoxybenzoyl)‐p‐phenylenediamine (BPBPPD), was prepared by the condensation of p‐phenylenediamine with 4‐phenoxybenzoyl chloride in N,N‐dimethylacetamide (DMAc). Novel aromatic poly(ether amide amide ether ketone ketone)s (PEAAEKKs) were synthesized by electrophilic Friedel–Crafts solution copolycondensation of BPBPPD with a mixture of terephthaloyl chloride (TPC) and isophthaloyl chloride (IPC), over a wide range of TPC/IPC molar ratios, in the presence of anhydrous aluminum chloride and N‐methylpyrrolidone (NMP) in 1,2‐dichloroethane (DCE). The influences of reaction conditions on the preparation of polymers were examined. The polymers obtained were characterized by different physico–chemical techniques such as FT‐IR, Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), and wide angle X‐ray diffraction (WAXD). The polymers with 70–100 mol% IPC are semicrystalline and have remarkably increased T_gs over commercially available poly(ether ether ketone) (PEEK) and poly(ether ketone ketone) (PEKK) due to the incorporation of amide groups in the main chain. The polymers with 70–80 mol% IPC had not only high T_gs of 209–213°C, but also moderate T_ms of 339–348°C, which are suitable for melt processing. The polymers with 70–80 mol% IPC had tensile strengths of 107.5–109.8 MPa, Young's moduli of 2.53–2.69 GPa, and elongations at break of 9–11% and exhibited high thermal stability and good resistance to organic solvents. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis,characterization, and antimicrobial activity of some novel poly(ether ketone)s

Low molecular weight poly(ether ketone)s were synthesized from phenol, 1,4‐phenylenedioxy diacetylchloride, chloroacetylchloride, and dichloroalkanes [1,2‐dichloroethane and dichloromethane] by a Friedel–Crafts reaction with anhydrous aluminum chloride as a catalyst and carbon disulfide as a solvent. The conditions for the preparation of the poly(ether ketone)s and the chlorine contents obtained with the Carius method were examined, and a reaction scheme for each resin was established. The molecular weights and polydispersities of the resins were obtained by gel permeation chromatography. The polyketones were characterized by IR spectroscopy. The characteristic frequencies due to different functional groups were assigned. The thermal properties of the resins were studied with thermogravimetry and differential scanning calorimetry. The characteristic temperatures of thermal degradation for the poly(ether ketone)s were evaluated with thermogravimetric analysis. The kinetic parameters for the decomposition reactions of the resins were obtained with Broido and Doyle's method, and the heats of fusion were obtained from differential scanning calorimetry thermograms. The polyketones were thermally stable up to 200 °C. All the polyketones were tested for their microbial properties against bacteria, fungi, and yeast. The effect of poly(ether ketone)s on the growth of these microorganisms was investigated, and the polyketones were found to inhibit the growth of the microorganisms to a considerable extent. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2335–2344, 2003     

Synthesis and Characterization of Novel Organosoluble Polychloro Substituted Aromatic Poly(Ether Ketone)s

A novel monomer of tetrachloroterephthaloyl chloride (TCTPC) was prepared by the chlorination of terephthaloyl chloride catalyzed by ferric chloride at 175‐180 °C for 10 h, and confirmed by FTIR, MS and elemental analysis. A series of new polychloro substituted poly(aryl ether ketone)s with inherent viscosities of 0.58‐0.65 dL/g have been prepared from TCTPC with aromatic ether monomers by electrophilic Friedel‐Crafts acylation in the presence of DMF with anhydrous AlCl₃ as a catalyst in 1,2‐dichloroethane. Glass‐transition temperatures of these polychlorinated polymers ranged from 267 to 280 °C by DSC. The degradation temperature at 5% weight loss by TGA in nitrogen for these polymers ranged from 486 to 534 °C, and the char yields at 700 °C were 54‐65%. The polymers having a weight‐average molecular weight in the range of 65,900‐79,300 are all amorphous and readily soluble in polar solvents such as DMF, DMSO and NMP at room temperature. All the polymers formed transparent, strong, and flexible films, with tensile strengths of 86.1‐99.7 MPa, Young's moduli of 2.32‐3.35 GPa, and elongations at break of 10‐15%.     

Structure‐controlled synthesis of novel soluble and thermally stable poly (aryl ether nitrile ether ketone ketone)/poly (aryl ether nitrile ether ketone biphenyl ketone) copolymers by electrophilic polycondensation

One new synthesis route was first designed to synthesize the biphenyl acid chloride (BPACl), and then a series of novel poly (aryl ether nitrile ether ketone ketone) (PENEKK)/poly (aryl ether nitrile ether ketone biphenyl ketone) (PENEKBK) copolymers with different controlled structure compositions were synthesized by electrophilic polycondensation and varying the molar ratio of BPACl to terephthaloyl chloride (TPC). The obtained PENEKK/PENEKBK copolymers were characterized by different physical and chemical techniques. The results showed, the copolymers with 10–50% molar contents of biphenyl moities exhibited good thermal properties with glass transition temperatures (T_gs) of 184–196°C, decomposition temperatures (T_ds) of 498–515°C, and good solubility in organic solvents (N‐Methyl‐2‐pyrrolidone (NMP), N,N‐dimethylformamide (DMF), and DMSO), indicating that they would have good potential for solvent processing. The thin films of the polymers had tensile strengths of 93.6–101.5 MPa, Young's moduli of 3.03–3.32 GPa, elongations at break of 9–14%, indicating they were strong materials. The densities of the obtained polymers were 1.31–1.40 g/cm^?3, which were far lower than those of some main inorganic materials (such as Fe, nearly 7.8 g/cm^?3), indicating that they would have possible potential for substituting some inorganic materials used as high temperature materials in some areas due to the merits of lightweight. Thus, the copolymers with 10–50% molar contents of biphenyl moities were promising polymer materials. Copyright © 2010 John Wiley & Sons, Ltd.     

13C-NMR study of arylene–ether–ketone copolymers

The chemical microstructure of arylene–ether–ketone copolymers of terephthaloyl chloride (TCl), 1,4-diphenoxybenzene (DPB), and diphenyl ether (DPE) has been characterized by ¹³C-NMR. Copolymers synthesized via two Friedel–Crafts reaction have been investigated; the first reaction uses HF and BF₃ to catalyze polymerization, and the second uses LiCl to moderate the activity of the Lewis-acid catalyst, AlCl₃. The HF/BF₃ approach results in random copolymers, in which the TCI displays no preference in reacting with either DPB or DPE. The buffered AlCl₃ approach yields somewhat blocky copolymers, in which the DPB and DPE tend to segregate. The degree of segregation in these materials has been quantified by formulas for the number-average block lengths.     

Polyaromatic ether-ketones containing various biphenylene units as crosslinking sites

Polyaromatic ether-ketones were prepared from diphenyl ether, isophthaloyl dichloride, and small amounts of 2,6-, 2,7-, 1,5-, and 1,8-dicarboxylic acid chloride of biphenylene, respectively, by Friedel–Crafts reaction. Biphenylene units were incorporated as crosslinking sites. Crosslinking is achieved by curing the polymers at 310–350°C for several hours. While the uncured resins are soluble in concentrated sulfuric acid, the fully crosslinked polymers are completely insoluble.     

Polycarbazoles via C?N coupling reactions of phthaloyl bis‐9H‐carbazoles with activated difluorides

1,3‐Phthaloyl bis‐9H‐carbazole (MPC) and 1,4‐phthaloyl bis‐9H‐carbazole (PPC) were synthesized by a Friedel‐Crafts reaction of carbazole with terephthaloyl chloride or isophthaloyl chloride. Homopolymers were obtained by a C? N coupling reaction with activated difluorides and copolymers were synthesized with 4,4′‐biphenol as a comonomer by a nucleophilic substitution reaction between these NH‐ and OH‐containing monomers and the activated difluoro monomers. The inherent viscosities of the polymers ranged from 0.35 to 1.03 dL/g. These polymers exhibited glass‐transition temperatures greater than 238 °C with the PPC‐containing homopolymer showing the highest value, 326.4 °C. The thermal stabilities indicated no significant weight loss below 450 °C and the temperatures of 5% weight loss ranged from 514.0 to 546.3 °C. The polymers showed reasonable solubility in organic solvents such as DMAC, DMSO, and NMP. UV absorption and fluorescence emission properties are presented. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4326–4331, 2009     

Stimuli‐responsive ABC triblock copolymers by sequential living cationic copolymerization: Multistage self‐assemblies through micellization to open association

Stimuli‐responsive ABC triblock copolymers with three segments with different phase‐separation temperatures were synthesized via sequential living cationic copolymerization. The triblock copolymers exhibited sensitive thermally induced physical gelation (open association) through the formation of micelles. For example, an aqueous solution of EOVE₂₀₀‐b‐MOVE₂₀₀‐b‐EOEOVE₂₀₀ [where EOVE is 2‐ethoxyethyl vinyl ether, MOVE is 2‐methoxethyl vinyl ether and EOEOVE is 2‐(2‐ethoxy)ethoxyethyl vinyl ether; the order of the phase‐separation temperatures was poly(EOVE) (20 °C) < poly(EOEOVE) (41 °C) < poly(MOVE) (70 °C)] underwent multiple reversible transitions from sol (<20 °C) to micellization (20–41 °C) to physical gelation (physical crosslinking, 41–64 °C) and, finally, to precipitation (>64 °C). At 41–64 °C, the physical gel became stiffer than similar diblock or ABA triblock copolymers of the same molecular weight. Furthermore, the ABC triblock copolymers exhibited Weissenberg effects in semidilute aqueous solutions. In sharp contrast, another ABC triblock copolymer with a different arrangement, EOVE₂₀₀‐b‐EOEOVE₂₀₀‐b‐MOVE₂₀₀, scarcely exhibited any increase in viscosity above 41 °C. The temperatures of micelle formation and physical gelation corresponded to the phase‐separation temperatures of the segment types in the ABC triblock copolymer. No second‐stage association was observed for AB and ABA block copolymers with the same thermosensitive segments found in their ABC counterparts. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2601–2611, 2004     

Living cationic polymerization of vinyl ethers with a naphthyl group: Decisive effect of the substituted position on naphthalene ring

Living cationic polymerization of a vinyl ether with a naphthyl group [2‐(2‐naphthoxy)ethyl vinyl ether, βNpOVE] was achieved using base‐assisting initiating systems with a Lewis acid. The Et_1.5AlCl_1.5/1,4‐dioxane or ethyl acetate system induced the living cationic polymerization of βNpOVE in toluene at 0 °C. The living nature of this reaction was confirmed by a monomer addition experiment, followed by ¹H NMR and matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) analyses. In contrast, the polymerization of αNpOVE was not fully controlled; under similar conditions, it produced polymers with broad molecular weight distributions. The ¹H NMR and MALDI‐TOF‐MS spectra of the resultant poly(αNpOVE) revealed that the products had undesirable structures derived from Friedel–Crafts alkylation. The higher reactivity of αNpOVE in electrophilic substitution reactions, such as the Friedel–Crafts reaction, was attributable to the greater electron density of the naphthyl ring, which was calculated based on frontier orbital theory. The naphthyl groups significantly affected the properties of the resultant polymer. For example, the glass transition temperatures (T_g) of poly(NpOVE)s are higher by approximately 40 °C than that of poly(2‐phenoxyethyl vinyl ether). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Imide-aryl ether ketone block copolymers

Imide-aryl ether ketone block copolymers were prepared and their morphology and thermal and mechanical properties investigated. Two aryl ether ketone blocks were incorporated; the first was an amorphous block derived from bisphenol–A and the second block was a semi-crystalline poly(aryl ether ether ketone) prepared from a soluble and amorphous ketimine precursor. Bis(amino) aryl ether ketone and aryl ether ketimine oligomers were prepared via a nucleophilic aromaic substitution reaction with molecular weights ranging from 6,000 to 12,000 g/mol. The oligomers were co-reacted with 4,4′-oxydianiline (ODA) and pyromellitic dianhydride (PMDA) diethyl ester diacyl chloride in N-methyl–2-pyrrolidone (NMP) in the presence of N-methylmorpholine. The copolymer compositions, determined by H-NMR, of the resulting amic ester based copolymers ranged from 8 to 50 wt % aryl ether ketone or ketimine content. Prior to imide formation, the ketimine moiety of the aryl ether ketimine block was hydrolyzed (p-toluene sulfonic acid) to the ketone form producing the aryl ether ether ketone block. Compositions of this block were maintained low to retain solubility. Solutions of the copolymers were cast and cured to effect imidization, producing clear films with high moduli (ca. 2200 MPa) and elongations (33–100%). The copolymers displayed good thermal stability with decomposition temperatures in excess of 450°C. Multiphase morphologies were observed irrespective of the co-block type, block length or composition. © 1992 John Wiley & Sons, Inc.     

Synthesis of ABA‐triblock and star‐diblock copolymers with poly(2‐adamantyl vinyl ether) and poly(n‐butyl vinyl ether) segments: New thermoplastic elastomers composed solely of poly(vinyl ether) backbones

ABA‐type triblock copolymers and AB‐type star diblock copolymers with poly(2‐adamantyl vinyl ether) [poly(2‐AdVE)] hard outer segments and poly(n‐butyl vinyl ether) [poly(NBVE)] soft inner segments were synthesized by sequential living cationic copolymerization. Although both the two polymer segments were composed solely of poly(vinyl ether) backbones and hydrocarbon side chains, they were segregated into microphase‐separated structure, so that the block copolymers formed thermoplastic elastomers. Both the ABA‐type triblock copolymers and the AB‐type star diblock copolymers exhibited rubber elasticity over wide temperature range. For example, the ABA‐type triblock copolymers showed rubber elasticity from about ?53 °C to about 165 °C and the AB‐type star diblock copolymer did from about ?47 °C to 183 °C with a similar composition of poly(2‐AdVE) and poly(NBVE) segments in the dynamic mechanical analysis. The AB‐type star diblock copolymers exhibited higher tensile strength and elongation at break than the ABA‐type triblock copolymers. The thermal decomposition temperatures of both the block copolymers were as high as 321–331 °C, indicating their high thermal stability. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Synthesis and characterization of polyimides from bis(3‐aminophenyl)‐4‐(1‐adamantyl)phenoxyphenyl phosphine oxide

A novel diamine, bis(3‐aminophenyl)‐4‐(1‐adamantyl)phenoxyphenyl phosphine oxide (mDAATPPO), was synthesized via the Williamson ether reaction of 4‐(1‐adamantyl)phenol and bis(3‐nitrophenyl)‐4‐fluorophenyl phosphine oxide, followed by reduction. The phenol group was prepared by the Friedel–Crafts reaction of 1‐bromoadamantane and phenol, whereas the phosphine oxide group was synthesized by the Grignard reaction of 1‐bromo‐4‐fluorobezene and diphenyl phosphinic chloride, followed by nitration. The monomer and its intermediate compounds were characterized with Fourier transform infrared, NMR, and melting‐point apparatus. The monomer was then used to prepare polyimides with 2,2‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride, 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride, 4,4′‐oxydiphthalic dianhydride, and pyromellitic dianhydride by the conventional two‐step synthesis: the preparation of poly(amic acid) followed by solution imidization. The molecular weights of the polyimides were controlled to 20,000 g/mol by off‐stoichiometry, and the synthesized polyimides were characterized with Fourier transform infrared, NMR, gel permeation chromatography, thermogravimetric analysis, and differential scanning calorimetry. In addition, the solubility, intrinsic viscosity, dielectric constant, and birefringence of the polyimides were evaluated. Novel polyimides with mDAATPPO exhibited good solubility, high glass‐transition temperatures (290–330 °C), excellent thermal stability (>500 °C), low dielectric constants (2.77–3.01), low refractive indices, and low birefringence values (0.0019–0.0030). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2567–2578, 2006     

Fully aromatic poly(ether ketone)s bearing macrocycle pendants: Synthesis and crosslinking

This study reports a method to prepare fully aromatic poly(ether ketone) thermosets. The cyclization of 2′,5′‐dimethoxy[1,1′‐biphenyl]‐2,5‐diol and a difluoro monomer was carried out under pseudo high dilution condition. Two types of fully aromatic poly(ether ketone)s with macrocycle were successfully prepared by copolymerization of macrocycle of aryl ether ketone containing hydroxyphenyl groups, 4,4′‐(hexafluoroisopropylidene)diphenol (HFBPA), and 4,4‐difluorobenzophenone. The obtained copolymers have high molecular mass, good solubility, and high glass transition temperatures in the presence of CsF, the crosslinking reaction of copolymers occurred and afforded fully aromatic thermoset poly(aryl ether ketone)s by ring‐opening reaction driven by entropy. After crosslinking, these copolymers show much higher glass transition temperatures, excellent thermal stability, and better mechanical strength. © Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7002–7010, 2008     

Alkyl-substituted poly(2,5-benzophenone)s synthesized via Ni(0)-catalyzed coupling of aromatic dichlorides and their miscible blends

High molecular weight poly(2,5-benzophenone) derivatives were prepared by Ni(0)-catalyzed coupling of 4′-substituted 2,5-dichlorobenzophenones. Monomers were synthesized by the Friedel–Crafts reaction of 2,5-dichlorobenzoyl chloride and alkyl-substituted benzenes in the presence of aluminum chloride. The resulting polymers are soluble and show no evidence of crystallinity by DSC. Number average molecular weights are in the range of 9.2 × 10³–11.7 × 10³ g/mol by multiple angle laser light scattering (MALLS). Molecular weights obtained by MALLS are only slightly lower (∼90%) than those obtained by GPC (polystyrene standards). These polymers exhibit high thermal stability with glass transition temperatures ranging from 173 to 225°C and weight loss occurring above 450°C in nitrogen and 430°C in air. Additionally, the polymers were blended and the resulting polymer films appear to be miscible by DSC results. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2611–2618, 1998     

Synthesis and characterization of novel aromatic poly(imide–benzoxazole) copolymers

New poly(imide–benzoxazole) copolymers were prepared directly from a dianhydride, a diacid chloride, and a bis(o‐diaminophenol) monomer in a two‐step method. In the first step, poly(amic acid–hydroxyamide) precursors were synthesized by low‐temperature solution polymerization in an organic solvent. Subsequently, the thermal cyclodehydration of the poly(amic acid–hydroxyamide) precursors at 350 °C produced the corresponding poly(imide–benzoxazole) copolymers. The inherent viscosities of the precursor polymers were around 0.19–0.33 dL/g. The cyclized poly(imide–benzoxazole) copolymers had glass‐transition temperatures in the range of 331–377 °C. The 5% weight loss temperatures ranged from 524 to 535 °C in nitrogen and from 500 to 514 °C in air. The poly(imide–benzoxazole) copolymers were amorphous, as evidenced by the wide‐angle X‐ray diffraction measurements. The structures of the precursor copolymers and the fully cyclized copolymers were characterized by Fourier transform infrared, ¹H NMR, and elemental analysis. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6020–6027, 2005     

Synthesis and properties of novel poly(aryl ether ketone)s containing both 2,6‐naphthylene moieties and amide linkages in the main chains

A new monomer, 2,6‐bis(4‐phenoxybenzoyl)naphthalene (BPOBON), was easily synthesized via simple synthetic procedures from readily available materials. A series of novel poly(aryl ether ketone)s containing both 2,6‐naphthylene moieties and amide linkages in the main chains were prepared by the Friedel‐Crafts acylation solution copolycondensation of isophthaloyl chloride with a mixture of BPOBON and N,N'‐bis(4‐phenoxybenzoyl)‐1,4‐phenylenediamine (BPBPPD), over a wide range of BPOBON/BPBPPD molar ratios, in the presence of anhydrous AlCl₃ and N‐methylpyrrolidone in 1,2‐dichloroethane. All the polymers are semicrystalline and had remarkably increased T_gs over the conventional PEEK and PEKK due to the incorporation of naphthalene and amide linkages in the main chains. The polymers with 50–70 mol% BPOBON had not only high T_gs of 179–186 °C, but also moderate T_ms of 321–328 °C, which are very suitable for the melt processing. These polymers had tensile strengths of 101.5–107.1 MPa, Young's moduli of 2.13–2.39 GPa, and elongations at break of 11.8–13.7% and exhibited excellent thermal stability and good resistance to organic solvents. Copyright © 2013 John Wiley & Sons, Ltd.     

Highly phenylated poly(aryl ether phthalazine)s

Two series of novel amorphous poly(aryl ether phthalazine)s have been prepared via an intramolecular ring closure reaction of poly(aryl ether ketone)s (PAEKs) with hydrazine monohydrate. Fluorinated PAEKs, which display solubility in solvents incorporating a ketone functionality such as acetone or ethyl acetate, were converted to poly(aryl ether phthalazine)s to observe if these polymers would display similar solubility characteristics. The poly(aryl ether phthalazine)s have glass transition temperatures in the range of 278–320°C and show 5% weight loss points greater than 500°C in air and nitrogen atmospheres. The fluorinated poly(aryl ether phthalazine)s were not soluble in ketonic solvents. A series of poly(aryl ether phthalazine)s incorporating pendant 2-naphthalenyl moieties has been prepared in an attempt to produce amorphous, thermally stable polymers with high glass transition temperatures. The polymers have glass transition temperatures in the range of 287–334°C and show 5% weight loss points greater than 500°C in air and nitrogen atmospheres. Poly(aryl ether phthalazine)s undergo an exothermic reaction above the glass transition temperature. The major product of this reaction is a rearrangement of the phthalazine moieties to quiazoline moieties, however some crosslinking of the polymers occurs. Cured samples of the poly(aryl ether phthalazine)s show a small increase in the polymer T_g and are insoluble in all solvents tested. © 1996 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 34:1897–1905, 1996     

Synthesis and characterization of halogen‐containing poly(ether ketone ketone)s

A series of novel poly(ether ketone ketone)s (PEKKs) were synthesized from diphenyl ether and isophthaloyl chloride derivatives such as 5‐halo‐ and 5‐tert‐butyl‐isophthaloyl chloride. The aromatic electrophilic substitution route to polyketones was a convenient route for the preparation of the polymers in high yields via precipitation polycondensation at a low temperature with aluminum trichloride as a catalyst. High molecular weight PEKKs were achieved with number‐average molecular weights of 15,000–100,000 g/mol for polymers that showed good solubility in organic solvents. The presence of substituents greatly modified the spectroscopic features in comparison with those of unsubstituted isophthaloyl poly(ether ketone ketone)s, particularly for the series containing halogens, for which significant variations of the chemical shifts in both ¹H and ¹³C NMR spectra were observed; these shifts could be related to the nature of the halogen. Thermal properties were also affected by the presence of pendent substituents, with clear enhancements of the glass‐transition temperatures, which could be ascribed to the nature and bulkiness of the substituents. Thermogravimetric analyses showed that the new polymers had good thermal resistance, although an important drop in thermal resistance was observed for polymers bearing large halogen atoms, such as bromine and iodine. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2601–2608, 2002