A new category of thermally stable poly(ether amide ether imide)s with increased solubility

Two new poly(ether amide ether imide)s (PEAEIs) were prepared from a new diamine (DA) containing ether, aliphatic, amide, naphthyl and pyridine functional groups that resulted flexible and thermally stable ultimate polymers. The DA was synthesized via two steps, starting from nucleophilic substitution reaction of 1,8‐diamino‐3,6‐dioxaoctane with 6‐chloronicotinoyl chloride in the presence of propylene oxide which, afforded dichloro‐diamide (DCDA) compound. In the second step for the preparation of DA, reaction of DCDA compound with 5‐amino‐1‐naphthol in the presence of K₂CO₃ was achieved. The new DA was then polycondensed with 2,2'‐bis‐(3,4‐dicarboxyphenyl) hexafluoropropane dianhydride and pyromellitic dianhydride to produce PEAEIs. The precursor, monomer and obtained polymers were entirely characterized by FT‐IR and ¹H‐NMR spectroscopy and elemental analysis techniques. The physical properties of the polymers including solubility, thermal behavior, thermal stability, inherent viscosity, morphology and mechanical properties were studied. The new PEAEIs exhibited favorable balance of physical and thermal properties, and their solubility was improved without sacrificing their thermal stability. Copyright © 2013 John Wiley & Sons, Ltd.     

Novel thermally stable poly(sulfone ether ester imide)s

A novel sulfone ether ester diamine was prepared by a three-step method. Reaction of 1,5-dihydroxy naphthalene with 4-nitrobenzoyl chloride afforded 5-hydroxy-1-naphthyl-4-nitrobenzoate. Reduction of nitro group by iron powder and HCl resulted in preparation of 5-hydroxyl-1-naphthyl-4-aminobenzoate. Reaction of this compound (two moles) with bis (4-chlorophenyl) sulfone led to preparation of a novel sulfone ether ester diamine. Three novel aromatic poly(sulfone ether ester imide)s were synthesized by polycondensation reactions of the prepared diamine with aromatic dianhydrides. Conventional methods were used to characterize the structure of the monomer and polymers. Physical properties of the polymers were also studied. The polyimides showed high thermal stability.     

Novel pyridine-based ether ester diamine and resulting thermally stable poly (ether ester amide)s

A novel pyridine-based ether ester diamine was prepared in three steps. Reaction of 1,5-dihydroxy naphthalene with 4-nitrobenzoyl chloride afforded 5-hydroxy-1-naphthyl-4-nitrobenzoate (HNNB). Reduction of nitro group resulted in preparation of an amino compound named 5-hydroxyl-1-naphthyl-4-aminobenzoate (HNAB). The diamine was synthesized by nucleophilic substitution reaction of 5-hydroxyl-1-naphthyl-4-aminobenzoate with 2,6-dichloropyridine in the presence of K₂CO₃. The obtained diamine was fully characterized and used to prepare novel thermally stable poly (ether ester amide)s via polycondensation reaction with different aromatic and aliphatic diacid chlorides. All the polymers were characterized and their physical and thermal properties were studied.     

Pore structure and glass transition temperature of nanoporous poly(ether imide)

The effect of nanopores on the glass transition temperature (T_g) of poly(ether imide) was studied with differential scanning calorimetry. Nanoporous poly(ether imide) samples were obtained through the phase separation of immiscible blends of poly(ether imide) and polycaprolactone diol and by the removal of the dispersed minor phase domains with a selective solvent. Microscopy and statistical methods were used to characterize the pore structure and obtain the pore structure parameters. The pore size was found to depend on the processing time and the initial blend composition, mainly because of phase-coarsening kinetics. A decrease in T_g was observed in the nanoporous poly(ether imide) in comparison with the bulk samples. The change in T_g was strongly influenced by the pore structure and was explained by the percolation theory. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3546–3552, 2006     

Determination of the glass transition temperature of polystyrene,poly(vinyl chloride) and poly(methyl methacrylate) using gas chromatography

The glass transition temperatures, Tg, of polystyrene, poly (vinyl chloride) and poly(methyI methacrylate) have been determined from gas chromatographic measurements using n-hexane, n-heptane, meta-xylene and para-xylene solvents. The glass transition temperatures were detected on the z-shaped retention diagrams which were produced from the plot of the logarithm of the specific retention volumes of the above-mentioned solvents against the reciprocal of temperature, i.e. log V${}_{\text{g}}^{\text{º}}$ vs. 1/T. The glass transition temperature is specified by the temperature where the slope of log V${}_{\text{g}}^{\text{º}}$ vs. 1/T changes abruptly. The observed glass transition temperature of polystyrene produced by this technique was found to be in good agreement with those produced by other techniques such as the differential scanning colorimeter. The industrial importance of the glass transition temperature, T_g, might be due to the dramatic changes in the physical properties of the polymer, such as hardness and elasticity, which take place in the vicinity of this temperature. However, perfectly crystalline polymers do not exhibit glass transitions, because their chains are incorporated in regions of three-dimensional order, called crystallites. Completely amorphous polymers and semi-crystalline polymers usually exhibit both glass transition and melting.     

Novel thermally stable poly(amine hydrazide)s and poly(amine‐1,3,4‐oxadiazole)s for luminescent and electrochromic materials

We describe the preparation, characterization, and luminescence of four novel electrochromic aromatic poly(amine hydrazide)s containing main‐chain triphenylamine units with or without a para‐substituted N,N‐diphenylamino group on the pendent phenyl ring. These polymers were prepared from either 4,4′‐dicarboxy‐4″‐N,N‐diphenylaminotriphenylamine or 4,4′‐dicarboxytriphenylamine and the respective aromatic dihydrazide monomers via a direct phosphorylation polycondensation reaction. All the poly(amine hydrazide)s were amorphous and readily soluble in many common organic solvents and could be solution‐cast into transparent and flexible films with good mechanical properties. These poly(amine hydrazide)s exhibited strong ultraviolet–visible absorption bands at 346–348 nm in N‐methyl‐2‐pyrrolidone (NMP) solutions. Their photoluminescence spectra in NMP solutions or as cast films showed maximum bands around 508–544 and 448–487 nm in the green and blue region for the two series of polymers. The hole‐transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. All obtained poly(amine hydrazide)s and poly(amine‐1,3,4‐oxadiazole)s exhibited two reversible oxidation redox couples at 0.8 and 1.24 V vs. Ag/AgCl in acetonitrile solution and revealed excellent stability of electrochromic characteristics, changing color from original pale yellow to green and then to blue at electrode potentials of 0.87 and 1.24 V, respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3245–3256, 2005     

Novel species of soluble thermally stable poly(keto ether ether amide)s: preparation,characterization, and properties

A new diamine containing one keto and four ether groups was prepared through a three‐step reaction: first, hydroquinone was reacted with 1‐fluoro‐4‐nitrobenzene and 4‐(4‐nitrophenoxy) phenol was obtained. The next step was reduction of nitro group to amino group in which 4‐(4‐aminophenoxy) phenol was prepared. In the final step, the new diamine named as bis(4‐(4‐(4‐aminophenoxy)phenoxy)phenyl) methanone was synthesized through reaction of the later compound with 4,4′‐difluoro benzophenone. All prepared materials were fully characterized by spectroscopic methods and elemental analysis. Novel species of poly(keto ether ether amide)s were synthesized via polymerization reaction of the diamine with different diacid chlorides including terephthaloyl chloride, isophthaloyl chloride, and adipoyl chloride. All polyamides were characterized, and their properties such as thermal behavior, thermal stability, solubility, viscosity, water uptake, and crystallinity were investigated and compared together. The glass transition temperatures of the polymers were about 204–232°C, and their 10% weight losses were in the range of 396–448°C. Polymers showed high thermal stability and enhanced solubility that mainly resulted from incorporation of the diamine structure containing keto, ether, and aromatic units into polyamide backbones. Copyright © 2014 John Wiley & Sons, Ltd.     

Living/controlled cationic cyclopolymerization of divinyl ether with a cyclic acetal moiety: Synthesis of poly(vinyl ether)s with high glass transition temperature based on incorporation of cyclized main chain and cyclic side chains

Cationic cyclopolymerization of 2‐methyl‐5,5‐bis(vinyloxymethyl)‐1,3‐dioxane ( 1 ), a divinyl ether with a cyclic acetal group, was investigated with the HCl/ZnCl₂ initiating system in toluene and methylene chloride at ?30 °C. The reaction proceeded quantitatively to give gel‐free, soluble polymers in organic solvents. The number‐average molecular weight (M_n) of the polymers increased in direct proportion to monomer conversion, and further increased on addition of a fresh monomer feed to the almost completely polymerized reaction mixture, indicating that the polymerization proceeded in living/controlled manner. The contents of the unreacted vinyl groups in the produced soluble polymers were less than ～3 mol %, and therefore, the degree of cyclization was determined to be ～97%. In contrast, the pendant cyclic acetal groups remained intact in the polymers under the present cationic polymerization conditions. These facts show that cyclopolymerization of 1 almost exclusively occurred and the poly(vinyl ether)s with the cyclized repeating units and cyclic pendant acetal rings were obtained. Glass transition temperature (T_g) and thermal decomposition temperature (T_d) of poly( 1 ) (M_n = 7870, M_w/M_n = 1.57) were found to be 166 and 338 °C, respectively, indicating that poly( 1 ) had high T_g and high thermal stability. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 952–958, 2010     

Relationship between morphology and glass transition temperature in solvent-crystallized poly(aryl ether ketones)

The relationship between semicrystalline morphology and glass transition temperature has been investigated for solvent-crystallized poly(ether ether ketone) (PEEK) and poly(ether ketone ketone) (PEKK). Solvent-crystallized specimens of both PEEK and PEKK displayed a sizeable positive offset in T_g compared to quenched amorphous specimens as well as thermally crystallized specimens of comparable bulk crystallinity; the offset in T_g for the crystallized samples reflected the degree of constraint imposed on the amorphous segments by the crystallites. Small-angle X-ray scattering studies revealed markedly smaller crystal long periods (d) for the solvent-crystallized specimens compared to samples prepared by direct cold crystallization. The strong inverse correlation observed between T_g and interlamellar amorphous thickness (l_A) based on a simple two-phase model was in excellent agreement with data reported previously for PEEK, and indicated the existence of a unique relationship between glass transition temperature and morphology in these poly(aryl ether ketones) over a wider range of sample preparation history and lamellar structure than was previously reported. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36 : 65–73, 1998     

Broadening of the glass transition in blends of poly(aryl ether ketones) and a poly(ether imide) as studied by thermally stimulated currents

Blends of poly(aryl ether ketones) (PAEKs) and an amorphous poly(ether imide) (PEI) were used as model systems to study the broadening of the glass transition due to crystallization and the resulting depletion of PAEK from the amorphous phase. Two different PAEKs were studied, which are completely miscible with PEI in the amorphous state; poly(aryl ether ether ketone) (PEEK) and a slower crystallizing poly(aryl ether ketone ketone)(PEKK). Relatively rapid crystallization conditions were chosen in order to trap a significant fraction of PEI between the PAEK crystal lamellae or between bundles of lamellae. The broad glass transitions are apparently a result of the nonuniform nature of this process. The breadth of the glass transition was quantified by thermally stimulated currents (TSC) applied in the thermal sampling (TS) mode. The results compared favorably with DSC data. The magnitude of the apparent activation energy obtained by the TS method allows one to assign the relaxations as cooperative (glass transition-like) or non-cooperative and to define the limits of the glass transition with a higher degree of precision than other techniques. Cooperative relaxations can be resolved with this technique, even if they are only a small fraction of the overall relaxing species at a given temperature. In some cases the glass transition region was found to broaden to ca. 60°C after crystallization. © 1993 John Wiley & Sons, Inc.     

Rheology of polystyrene/poly(vinyl methyl ether)blends near the phase transition

Mixtures are expected to show anomalous behavior in their viscoelastic properties close to a critical point. In this study, the reheological behavior of blends of polystyrene and poly (vinyl methyl ether) below, close to, and above the phase separation temperature T_s was investigated. Rheological measurements were carried out at three different compositions in the melt. Below and far from T_s, a satisfactory superposition of the storage and loss moduli G' and G″ was observed at all temperatures and frequencies. Close to T_s deviations were observed for G' at low frequencies (the so-called terminal zone). Above T_s G″ values was still observed over the whole range of frequencies and temperatures. The deviations observed for G' near T_s can be interpreted as due to the presence of significant concentration fluctuations. Plots of log (G'/G″²) as a function of temperature were shown to be sensitive to this anomalous behavior.     

Processable polyisoimide polymer blends for application as thermally stable adhesives for composites and advanced metal alloys

Polyimides are effective thermally stable bonding agents for substrates including titanium, aluminum alloys, steel alloys, metal matrix composites, and polymer/fiber composites with good tolerance toward elevated temperature and humidity. Problems associated with polyimide adhesives, including high processing temperatures and pressures and high melt viscosity, can be partially or totally alleviated by use of blends of polyisoimides. During thermal processing, the polyisoimides are isomerized to their polyimide modifications.     

New thermally stable and organosoluble heterocyclic poly(naphthaleneimide)s

As majority of polyheteroarylenes based on bis(naphthalic anhydrides), are difficult to process due to their infusiblity and insolubility in common organic solvents and solubility only in strong acids, this study is concerned with the synthesis and properties of new, easily processable polyimides and copolyimides containing naphthalene and oxadiazole rings. These polymers have been synthesized and their properties have been compared with regard to the influence of oxadiazole and naphthalene units on their physical properties. The polyimides were prepared by polycondensation reaction in solution of the aromatic diamines containing preformed oxadiazole ring with two dianhydrides having naphthalene units, at high temperature. Also, copolyimides were prepared by using a mixture of each naphthalene‐containing dianhydride, with hexafluoroisopropylidene‐dianhydride in the polycondensation reaction with the same diamino‐oxadiazoles. Most of the resulting polyimides and copolyimides were soluble in polar amidic solvents and in less polar solvents, and their solutions gave flexible films when spread onto glass plates. The thermal stability and glass transition temperature of these polyimides and copolyimides were measured and compared. The quality and the roughness of the spin‐coated films of these polymers were investigated by atomic force microscopy. The photoluminescence properties of the polymers in solution were studied to determine the color of emission. The UV absorption was also studied to determine the Stokes shift, and hence the possible reabsorption effects. The properties of the present polyimides make them attractive for applications in advanced optoelectronics and other related fields. Copyright © 2009 John Wiley & Sons, Ltd.     

Biodegradable poly(carbonate‐ether)s with thermoresponsive feature at body temperature

Novel biodegradable poly(carbonate‐ether)s (PCEs) with lower critical solution temperature (LCST) at body temperature were synthesized by copolymerization of CO₂ and ethylene oxide (EO) under double metal cyanide (DMC) catalyst. The PCEs showed carbonate unit (CU) content of 1.0–42.4 mol % and molecular weight of 2.7–247 kg/mol, which exhibited reversible thermoresponsive feature in deionized water with LCST in a broad window from 21.5 to 84.1 °C. The LCST was highly sensitive to the CU content and the molecular weight of PCEs, and it showed a linear relation with CU content for PCEs with similar molecular weight. In particular, aqueous solution of PCE with a 26.0 mol % of CU showed an LCST around 36.1 °C, which was very close to the body temperature. Interestingly, it was found that the phase transition behavior changed with PCE concentration. For PCE with M_n of 2.7 kg/mol and CU content of 30.0 mol %, the LCST increased from 21.5 to 36.7 °C when the PCE concentration changed from 10 to 1 g/L. Dynamic light scattering indicated that the phase transition was possibly due to a coil‐to‐globule transition. The thermoresponsive biodegradable PCE with LCST at body temperature is promising for biomedical applications, especially for in vivo applications. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Aromatic poly(sulfone sulfide amide imide)s as new types of soluble thermally stable polymers

A new diamine monomer containing flexible sulfone, sulfide, and amide units was prepared via three steps. Nucleophilic chloro displacement reaction of 4‐aminothiophenol with 4‐nitrobenzoyl chloride in the presence of propylene oxide afforded N‐(4‐mercapto‐phenyl)‐4‐nitrobenzamide and subsequent reduction of the nitro intermediate led to 4‐amino‐N‐(4‐mercapto‐phenyl)benzamide. Two moles of this amino thiophenol compound was reacted with bis‐(4‐chloro phenyl)sulfone to provide a novel diamine monomer. The diamine was reacted with aromatic dianhydrides to form polyimides via a two‐step polycondensation method, formation of poly(amic acid)s, followed by chemical imidization. The resulting polymers were characterized and their physical properties including thermal behavior, thermal stability, solubility and inherent viscosity were studied. Copyright © 2007 John Wiley & Sons, Ltd.     

Poly(oxanorbornenedicarboximide)s dendronized with amphiphilic poly(alkyl ether) dendrons

Attaching dendritically branched side chains to each repeat unit of a linear polymer produces molecular building blocks of nanometer‐sized dimensions called dendronized polymers. The structure of these complex molecular architectures is highly tunable and, therefore, of interest for a wide range of potential applications. The first examples of dendronized polymers prepared by living ring‐opening metathesis polymerization of oxanorbornenedicarboximide macromonomers with poly(alkyl ether) dendrons are reported. Small‐angle X‐ray scattering experiments on bulk samples confirm that the diameter of the individual cylindrical polymers can be tailored by the choice of dendron generation or the length of the hydrocarbon peripheral group. Analysis of the SAXS data based on a core‐shell model indicates that although the diameter of the cylinder increases with generation, the size of the core does not change; this suggests that these dendrons only loosely encapsulate the polymer backbone. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3221–3239     

Optically active polymers containing side-chain azobenzene moieties: Photochromic and photoresponsive behavior of copolymers of N-(4-azobenzene) maleimide with (−)-menthyl vinyl ether and (+) (S)-2-methylbutyl vinyl ether

Photochromic behavior and photoisomerization kinetics of optically active copolymers of trans-N-(4-azobenzene) maleimide (ABM) with (?) -menthyl vinyl ether (MtVE) and (+) (S) -2-methylbutyl vinyl ether were studied by UV spectroscopy under irradiation at 348 nm. The resulting data have been compared with those of the corresponding copolymers containing also trans-N-(4-azobenzene) maleamic acid co-units as well as of low molecular weight model compounds. The photoresponsive behavior has been also investigated by circular dichroism measurements at various extents of photoisomerization. The results are discussed in terms of structural requirements of the macromolecules. © 1994 John Wiley & Sons, Inc.