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Colorless-to-colorful switching electrochromic polymers with very high contrast ratio are unattainable and attractive for the applications of smart wearable electronics. Here we report a facile strategy in developing colorless-to-colorful switching electrochromic polyimides by incorporating with alicyclic nonlinear, twisted structures and adjusted conjugated electrochromophores, which minimize the charge transfer complex formation. It is noted that, by controlling the conjugation length of electrochromophore, the colorless-to-black switching electrochromic polymer film (PI-1a) exhibites an ultrahigh integrated contrast ratio up to 91.4% from 380 to 780 nm, especially up to 96.8% at 798 nm. In addition, PI-1a film with asymmetric structure also demonstrates fast electrochemical and electrochromic behaviors (a switching and bleaching time of 1.3 s and 1.1 s, respectively) due to the loose chain stacking, which provides more pathways for the penetration of counterion. Moreover, the colorless-to-black EC device based on PI-1a reveals an overall integrated contrast ratio up to 80%., Electrochromic polymers (ECPs) receive great attention due to their facile colour tunablility, however colourless-to-black ECPs with high contrast ratio are still unattainable. Here the authors develop high contrast colourless-to-black switching polyimides by following specific molecular design criteria.

Soluble aromatic polyimides and polyvinyls were prepared by incorporating pyridine moiety and its derivatives in the backbone and the side groups, respectively: 6F-Py-i polymers based on the polyimide backbone (6F-Py-1 to 6F-Py-7) and PVPy-i polymers based on the polyvinyl backbone (PVPy-1 to PVPy-4). All polymers were found to be amorphous. The 6F-Py-i polymers were thermally stable up to 511–545 °C; the PVPy-i polymers were stable up to 362–376 °C. Their glass transitions, thin film densities, molecular orbitals, and band gaps were determined. The electrical devices fabricated with the polymers in an electrode/polymer/electrode structure revealed p-type unipolar write-once-read-many times (namely, permanent) or dynamic random access memory or dielectric behavior, depending on the substituents of the pyridine unit and the film thicknesses. In particular, such digital memory characteristics were found to originate from the pyridine moieties possessing a high charge affinity in the polymers. However, the pyridine moieties were found to still need at least two or more aromatic substituents to get enough power to stabilize charges via utilizing the resonance effects provided by the substituents. Overall, this study demonstrated that the pyridine unit conjugated with two or more aromatic substituents is a very useful component to design and synthesize digital memory materials based on thermally stable polyimides and other high performance polymers. The 6F-Py-i polymers have potential for the low-cost mass production of high-performance programmable unipolar permanent memory devices with very low power consumption.

In this work, we present a novel pyrene-functionalized benzoxazine (Py-BZ)/single-walled carbon nanotubes (SWNTs) complex material as an efficient luminescent chemosensor for gaseous amines. It is shown that an interaction of poly(Py-BZ)/SWCNTs nanocomposites with analyte vapor leads to the increase of the intensity of luminescence. The response of these sensors to methylamines by static and dynamic flow measurement were studied.

In this study, a novel conjugated polymer, denoted as ECPblack, is synthesized. ECPblack demonstrated a unique electrochromic behavior with an ultrahigh contrast ratio (over 80%) in most of the visible regions, boasting an ultrahigh integrated contrast ratio of 71.8% between 380 nm and 880 nm. The long conjugated pendant group (pyrene) in ECPblack enhances the absorption in the blue region in its second oxidized state and results in transmissive-to-black electrochromic switching between the neutral state and the oxidized state. The transmissive-to-black electrochromic switching polymer with an ultrahigh contrast ratio could be especially attractive for applications in electronic displays. In addition, when polytriarylamine/nanotube (SWNT/P2) dispersion is doped in ECPblack, the response time of its electrochemical and electrochromic behaviors is further reduced. The electrochromic switching and bleaching time of SWNT/P2/ECPblack decreased by 73% and 80%, respectively. The improvement is caused by the phase separation of the rigid SWNT and the flexible polymer, which generates a rough surface morphology and provides more pathways for faster diffusion of counterions (ClO4−). The polymer/SWNT doping technique provides a simple way to accelerate ion diffusion in anodically coloring materials.

In this work, polymers of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-triphenylamine] with side chains containing: pyrene (C1), diphenyl (C2), naphthalene (C3), and isopropyl (C6) structures were synthesized via a Suzuki coupling reaction. The structures were verified using NMR and cyclic voltammetry measurements provide the HOMO and LUMO of the polymers. The polymer with pyrene (C1) and naphthalene (C3) produced photoluminescence in the green while the polymer with the side chain containing diphenyl (C2) and isopropyl (C6) produce dual emission peaks of blue-green photoluminescence (PL). In order to examine the electroluminescence properties of the polymers, the solutions were spin-coated onto patterned ITO anode, dried, and subsequently coated with an Al cathode layer to form pristine single layer polymer LEDs. The results are compared to a standard PFO sample. The electroluminescence spectra resemble the PL spectra for C1 and C3. The devices of C2, C3, and C6 exhibit voltage-dependent EL. An additional red emission peak was detected for C2 and C6, resulting in spectra with peaks at 435 nm, 490 nm, and 625 nm. The effects of the side chains on the spectral characteristics of the polymer are discussed.

In this work, a water/alcohol-soluble conjugated polymer poly [(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9–dihexylfluorene)] (PFNC6) is synthesized and the photophysical properties are investigated. Subsequently, it is tested as electron injection layer in a blue emitting OLED with PFO. The maximum current efficiency (CE) and external quantum efficiency (EQE) of the device increased by 3 times to 0.75 cd/A and 0.66%. Further enhancement in the OLED performance is obtained when a bilayer electron injection consisting of PFNC6 and LiF are used where the maximum CE is 2.16 cd/A and the maximum EQE is 1.55%. Measurement with electron-only-devices confirmed that the electron mobility is increased for the device with PFNC6 as compared to the control device. Furthermore, higher Vbi is obtained in photovoltaic measurement when PFNC6 is used. As a result, the electron injection barrier is reduced and electron injection is more efficient.

A new approach for polytriarylamine (PTAA)-assisted selective dispersion for single-walled carbon nanotubes (SWNTs) in a toluene solution has been developed. The triarylamine-based conjugated polymers are able to selectively wrap the SWNTs with specific chiral indices depending on their backbone structures (e.g., PTAA12, PTAA12-P, and PTAA12-BP) and side-chain functionality (e.g., PTAA6, PTAA6-alt-PTAA, and PTAA12-alt-PTAA). PTAA12 exhibits highly selective wrapping for the (6,5) chirality from CoMoCAT (catalytic processes) SWNTs but low selectivity in a dispersion of HiPCO (high-pressure carbon monoxide) SWNTs. Therefore, the selection for HiPCO SWNTs has been further improved via PTAA12-alt-PTAA wrapping with alternating side chains and mainly exhibits a high affinity to (6,5) SWNTs with high chiral angles (≥24.5°). The wrapping conformation and binding energy of the polymer/(6,5) SWNTs were studied via molecular modeling, and the simulated results are in good agreement with the experimental data for th...

Electrochromic polymers are attractive materials with enormous potential in the rapidly developing area of plastic electronics due to their flexibility, low-power consumption, ease of processing and low processing cost. Electrochromic devices created with electrochromic polymers are likely to be alternatives or supplements to the conventional inorganic electrochromic devices, which face challenges of durability and electrochromic properties. Several novel electrochromic polyimides, polyamides, and polynorbornenes prepared via polycondensation, ring-opening metathesis polymerisation (ROMP), etc., are introduced in this article. These various polymer species exhibit high thermal stability and mechanical strength.

A composite sorbent modified with fluorinated aromatic polyamide, for single-step isolation of DNA from biological mixtures is developed. The sorbent is prepared by the polymer deposition from solution onto the surface of porous silica. It is shown that the polymer coating with a thickness of 4 nm is formed not only on the outer surface of the carrier particles but also on the inner pore surfaces. It is found that the material produced largely retained porosity of the pristine support and the material is selective in a one-step separation of nucleic acids and proteins by passing the bacterial lysate through a sorbent. The degree of purification of the isolated preparations of DNA is sufficient to be used directly in PCR analysis.

The effect of chemical composition and morphology of the surface layers of new polyaramide-containing sorbents on the mechanism of selective sorption of nucleic acids and proteins was investigated as compared to the previously studied sorbents modified with fluoropolymers and polyaniline (high-throughput materials providing one-step isolation of DNA from biological mixtures). A series of silica-based sorbents modified with polyaramides having consistently varying structure and containing the set of "key" structural elements (aromatic units and nitrogen atoms in the backbone, fluorinated groups), and various donor and acceptor moieties was prepared. The chemical composition of the polymer coatings was evaluated by X-ray photoelectron spectroscopy. The surface morphology was studied by scanning probe microscopy. The sorption properties were investigated by passing the mixtures containing DNA, RNA and proteins of different nature through the cartridges containing the obtained sorbents. All the investigated materials weakly retain double-stranded DNA but effectively retain RNA and proteins. The sorption capacity of the sorbents depends on the protein nature. The observed sorption behavior was shown to be determined by the chemical structure and not by the morphology of the polymer coating. It was proposed that similarity of the sorption properties of the series of chemically different polymers could be determined by similar total input of different sorption mechanisms.

Novel conjugated polymers such as poly(phenylene-fluorene) P1 and poly(triphenylbenzene-fluorene) P2 with hexaphenylbenzene (HPB) as a pending side group were prepared by Suzuki coupling using the dibromo monomers M1 and M2 with 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propanediol) ester, respectively. The HPB moiety of P1 and P2 can be oxidatively cyclodehydrogenated with FeCl3 in nitromethane, yielding polymers P3 and P4 with hexa-peri-hexabenzocoronene (i.e., nanographene) units. The cyclodehydrogenation of nanographene-containing polymers was confirmed by FT-IR spectroscopy. In addition, X-ray powder diffraction of both P3 and P4 revealed a polymer interlayer spacing of 1.3 nm being dominated by the nanographenes. The glass transition temperatures (Tgs) of P1 and P2 were 202 °C and 235 °C, respectively, while both P3 and P4 with nanographenes possessed Tgs higher than 300 °C. Compared to P3, P4 with a triphenylbenzene moiety in its backbone can be well dispersed without aggregation in N-cyclohexyl-2-pyrrolidone (CHP), as confirmed by UV-Vis spectroscopy, photoluminescence spectroscopy (PL) and photoluminescence-excitation (PLE) maps.

Polyimides rank among the most heat-resistant polymers and are widely used in high temperature plastics, adhesives, dielectrics, photoresists, nonlinear optical materials, membrane materials for separation, and Langmuir–Blodgett (LB) films, among others. Additionally, polyimides are used in a diverse range of applications, including the fields of aerospace, defense, and opto-electronics; they are also used in liquid crystal alignments, composites, electroluminescent devices, electrochromic materials, polymer electrolyte fuel cells, polymer memories, fiber optics, etc. Polyimides derived from monomers with noncoplanar (kink, spiro, and cardo structures), cyclic aliphatic, bulky, fluorinated, hetero, carbazole, perylene, chiral, non-linear optical and unsymmetrical structures have been described. The syntheses of various monomers, including diamines and dianhydrides that have been used to make novel polyimides with unique properties, are reported in this review. Polyimides, with tailored functional groups and dendritic structures have allowed researchers to tune the properties and applications of this important family of high-temperature polymers. The synthesis, physical properties and applications of advanced polyimide materials are described.

Novel bi-triphenylamine-containing aromatic dibro- mide M3, N,N-bis(4-bromophenyl)-N 0 ,N 0 -dipheny-l,4-phenylene- diamine, was successfully synthesized. The novel conjugated polymer P1 having number-average molecular weight of 1.31 � 10 4 was prepared via Suzuki coupling from the dibromide M3 and 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propane- diol) ester. Polymer P1 had excellent thermal stability associ- ated with a high glass-transition temperature (Tg ¼ 141 � C). The hole-transporting and UV-vis-near-infrared electrochromic properties were examined by electrochemical and spectroelec- trochemical methods. Cyclic voltammograms of the conjugated polymer films cast onto indium-tin oxide-coated glass sub- strates exhibited two reversible oxidation redox couples at E1/2 values of 0.73 and 1.13 V versus Ag/Ag þ in acetonitrile solu- tion. The hole mobility of the conjugated polymer P1 revealed � 10 � 3 cm 2 V � 1 s � 1 , which is much higher than that of other conjugated polymer systems. The observed UV-vis-near- infrared absorption change in the conjugated polymer film P1 at applied potentials ranging from 0.00 to 1.23 V are fully reversible and associated with strong color changes from pale yellowish in its neutral form to green and blue in its oxidized form. Using a combination of experimental study and theo- retical investigation, we proposed an oxidation mechanism based on molecular orbital theory, which explains the cyclic voltammetry experimental results well. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4654- 4667, 2010

A series of novel organosoluble polyimides and copolyimides with a propeller-shaped triarylamine unit were prepared from diamine and various aromatic dianhydrides via direct polycondensation. All of the polymers possessed tough, flexible, and strong films with high molecular weights. The polyimide and copolyimide films revealed electrochromic characteristics, with a color change from pale yellowish at its neutral state, to green, and finally to blue at its oxidized state, at applied potentials ranging from 0 to 1.50 V. The polyimide (Ib) film exhibited switching times of 4.5 s at 1.08 V at 424 and 877 nm and 1.9 s for fast bleaching due to a pendent substituted 2-phenyl-2-isopropyl group. Cyclic voltammetry (CV) of the polymer films showed two reversible redox couples at potentials of 0.91–0.99 V and 1.30–1.38 V, respectively. The CV results of the model compound M1 and model polyimide M2, were not a match to the oxidation peaks of polyimide Ib, indicating that the contribution of the oxidation was not only from the electron removal of nitrogen atoms.

A new rapid switching near-IR electrochromic conjugated propeller-shape polymer (PBTPAFL) with lower oxidation potential containing a di-triarylamine group was synthesized via Suzuki coupling approach. The observed UV-vis-NIR absorption changes in the PBTPAFL film at various potentials are fully reversible and associated with strong color changes from the original light green to dark green and then to a Prussian blue. Excellent continuous cyclic stability of the electrochromic characteristics with a rapid color switching time 2.58 s and bleaching time 1.76 s was found as well. Compared with P1 and P2, the introduction of more electron-donating propyl phenyl group in the para position of PBTPAFL lowered the oxidative potential and prevented coupling reaction during the electrochromic procedure. The high molecular weight conjugated polymer having high thermal stability with T d10 more than 450 °C has excellent solubility in common organic solvents such as NMP, THF, chloroform, toluene, xylene, and benzene at room temperature (25 °C) due to the propeller-shape structure and long alkyl chain on fluorene. Herein, from the combination of the experimental and computational study, we proposed a mechanism on the basis of the molecular orbital theory to explain the electrochromic oxidation behavior.

A novel dibromo compound containing unsymmetrical substituted bi-triarylamine was synthesized. A conjugated polymer was prepared via the Suzuki coupling from the newly prepared dibromo compound and 9,9-dioctylfluorene-2,7-bis(tri-methyleneboronate). The glass transition temperature (T g ) of the conjugated polymer was 140 °C, 10% weight-loss temperatures (T d10 ) in nitrogen was 458 °C, and char yield at 800 °C in nitrogen higher than 64%. Cyclic voltammogram of the polymer film cast onto an indium-tin oxide (ITO)-coated glass substrate exhibited two reversible oxidation redox couples at 0.70 and 1.10 V versus Ag/Ag + in acetonitrile solution. The polymer films revealed excellent stability of electrochromic characteristics, with a color change from yellow green of the neutral form to the dark green and blue of oxidized forms at applied potentials ranging from 0 to 1.3 V. The color switching time and bleaching time were 4.25 and 7.22 s for 860 nm and 5.51 s and 6.48 s for 560 nm.

A bipolar dibromo monomer, bis-(4-bromophenyl)[4-(3,5-diphenyl-1,2,4-triazole-4-yl)-phenyl]amine (9), containing electro-rich triphenylamine and electro-deficient 1,2,4-triazole moieties was newly synthesized and characterized. Two fluorescent fluorene-based conjugated copolymers (TPAF, TPABTF) were prepared via facile Suzuki coupling from the dibromo bipolar monomer, 4,7-dibromo-2,1,3-benzothiadiazole (BTDZ), and 9,9-dioctylfluorene. They were characterized by molecular weight determination, IR, NMR, DSC, TGA, solubility, absorption and photoluminescence spectra, and cyclic voltammetry. The polymers showed good solubility in common organic solvents such as dichloromethane, chloroform, tetrahydrofuran, and dichlorobenzene at room temperature. They had glass transition temperatures (T g ) higher than 135 °C and 5% degradation temperatures in nitrogen atmosphere were higher than 428 °C. Single layer polymer light-emitting diodes (PLED) of ITO/ PEDOT:PSS/polymer/metal showed a blue emission at 444 nm and Commission Internationale de I'Eclairage (CIE) 1931 color coordinates of (0.16, 0.13) for TPAF. The device using TPABTF as emissive material showed electroluminescence at 542 nm with CIE1931 of (0.345, 0.625), low turn-on voltage of 5 V, a maximum electroluminance of 696 ed/m 2 , and a peak efficiency of 2.02 cd/A.

A series of novel amphiphilic fluorescent CBABC-type pentablock copolymers ( Py – PMMA – PEG4600 – PMMA – Py ) were prepared from BAB-type amphiphilic triblock copolymer ( PMMA – PEG4600 – PMMA ) as macroinitiator with various contents of 1-(methacryloyloxyethylamino-carboxylmethyl) pyrene ( PyMOI ) by atom transfer radical polymerization (ATRP) in toluene using CuBr/2,2-bipyridine as catalyst system. Triblock copolymer ( PMMA – PEG4600 – PMMA ) was prepared by ATRP and obtained from Br – PEG4600 – Br as macroinitiator with methyl methacrylate in tetrahydrofuran using the same catalyst. The molecular weights of pentablock copolymers which were reinitiated by PMMA – PEG4600 – PMMA macroinitiator were calculated from 1 H NMR spectra up to 42,400 gmol −1 . The polydispersity of pentablock copolymers obtained from GPC analysis was narrow between 1.10 and 1.38. The crystallinity of triblock copolymer ( PMMA – PEG4600 – PMMA ) was decreased slightly with incorporating PMMA segment. Introducing the bulky pyrene substituent into pentablock copolymer, the melting temperature was not observed and all pentablock copolymers showed amorphous patterns in wide-angle X-ray scattering (WAXS) due to decrease in the degree of crystallinity of polymer chain because of disturbing regular packing. The temperatures at 10% weight loss (Td 10 ), examined by TG analysis, showed values ranging from 265 to 323 °C in nitrogen and 264 to 313 °C in air. Fluorescence spectra of Py – PMMA – PEG4600 – PMMA – Py exhibited stronger excimer emission at ca . 480 nm due to the aggregations of pyrene group formed via interaction of the hydrophobic chains. The more content of PyMOI segment in pentablock copolymers can obtain the higher emission intensity ca . 480 nm. When there were higher PyMOI contents (84.9 wt% PyMOI ) in pentablock copolymers, they formed larger aggregates (210 nm) in SEM micrographs. On the other hand, while increasing the concentration of the polymer solution in THF, the morphology was changed from spherical (0.1 mg/mL) to chainlike (1.0 mg/mL) aggregates.

A new diiodo monomer containing heterocyclic pyridine and carbazole groups was synthesized via Chichibabin reaction and used in the preparation of a conjugated polymer via Suzuki coupling approach. The conjugated polymer was highly soluble in common organic solvents such as NMP, THF, dichloromethane, chloroform, toluene, xylene, and benzene at room temperature. The polymer had high glass transition temperature at 191 °C and Td10 at 434 °C in nitrogen atmosphere. The pristine polymer exhibited the UV–vis maximum absorption at 355 nm and shifted to 420 nm after protonation. The emission of the polymer in THF solution changed from the blue region with maximum peak at 400 nm to the yellow region with maximum peak at 540 nm after protonated by HCl, and the intensity of emission depended on the concentration of acid. The polymer also showed electrochromic behavior under applied voltage. The emission color of the polymer film changed from blue (435 nm) to yellow (570 nm) when 2.5 V bias voltage was applied. The polymer also exhibited write-once and read-many-times (WORM) polymer memory effect with tristable states. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 991–1002, 2009

Novel optically transparent, low dielectric and highly organosoluble alicyclic polyamides derived from bulky alicyclic diamine containing trifluoromethyl group on either side, 1,1-bis[4-(2-trifluoromethyl-4-aminophenoxy)phenyl]-4-tert-butylcyclohexane (BTFAPBC), were prepared. The polyamides were obtained in almost quantitative yields and showed inherent viscosity values between 0.55 and 0.72 dL g−1 in DMAc solution. Most of the polyamides showed excellent solubility in polar solvents such as N-methyl-2-pyrrolidinone (NMP), N,N′-dimethyl acetamide (DMAc), N,N′-dimethyl formamide (DMF), pyridine, cyclohexanone, γ-butyrolactone and chloroform. The cut-off wavelength for polyamides ranged from 350 to 388 nm. Polyamides with alicyclic tert-butylcyclohexyl cardo and trifluoromethyl substituents exhibited low dielectric constants ranging from 3.29 to 3.98 (at 100 Hz) compared with commercially available polyamides [Amodel®, 4.2–5.7 at 100 Hz]. Polyamides showed glass transition temperatures in the range of 244–266 °C and possessed a coefficient of thermal expansion (CTE) of 60–75 ppm °C−1. Thermogravimetric analysis data showed that the polyamides were stable up to 430 °C and the 10% weight loss temperature was found to be in the range of 437–466 °C in nitrogen atmosphere. The polyamide films had a tensile strength in the range of 66–103 MPa, elongation at break in the range of 5–8%, and tensile modulus in the range of 1.5–2.2 GPa. Due to their properties, the polyamides could be considered as engineering plastic and photoelectric materials.

In order to investigate the photochemical tuning capability of chiral monomers and polymers containing end‐capped menthyl groups, a new series of chiral dopants was synthesized and added to commercially available nematic liquid crystals to induce cholesteric liquid crystal (LC) phases. The addition of chiral dopants with azo structure led to phototunability of the reflection colour of the LC cells. Photochromic variation of the LC cells due to photoisomerization of the azo compound was investigated. After photopolymerization of the monomers inside the cholesteric LC cells, the centre wavelength of the reflected band of the incident light was found to be fixed and the reflected bandwidth was broadened, resulting in a red shift. A schematic representation of both the photoisomerization of the azo dopants and its effect on variation of twisting pitches is proposed. Real image recording was performed using 365 nm UV through a mask with text. The top and side views of the morphological network structures of a ...

Novel highly stable polynorbornenes with self-assembling amphiphilic architecture containing hydrophilic ammonium salt and hydrophobic alkyl ester group were obtained via ring-opening metathesis polymerization (ROMP) of 5-(octanoate methyl)bicyclo[2.2.1]hept-2-ene (NBMO) and 5-(phthalimide methyl)bicyclo[2.2.1]hept-2-ene (NBMPI), hydrogenation, hydrazinolysis, and subsequent quaternization. Polymeric micelles of such amphiphilic random and block polynorbornenes formed in solvents by varying the content of ammonium salts were investigated. Amphiphilic block copolymers exhibited perfect spherical morphology. Nanoscale polymeric micelles of random copolymers with 50–75 mol% of ammonium salts were roughly spherical in shape, while the morphologies of micelles transferred into network-like aggregates as hydrophilic contents of the random copolymers are higher than 80 mol%. The formation and fine structures of micelles were investigated by dynamic light scattering (DLS), TEM, and fluorescence technique using pyrene as fluorescence probe.

A series of novel polyamide-imides (PAIs) with high glass transition temperature were prepared from diimide-dicarboxylic acid, 2,2′-bis(trifluoromethyl)-4,4′-bis(trimellitimidophenyl)biphenyl ( BTFTB ), by direct polycondensation with various diamines in N -methyl-2-pyrrolidinone using triphenyl phosphite and pyridine as condensing agents in the presence of dehydrating agent (CaCl 2 ). The yield of the polymers was obtained was high with moderate to high inherent viscosities (0.80–1.03 dL g −1 ). Gel permeation chromatography (GPC) of the polymers showed number-average and weight-average molecular weights up to 8.6 × 10 4 and 22 × 10 4 , respectively. The PAIs were amorphous in nature. Most of the polymers exhibited good solubility in various solvents such as N -methyl-2-pyrrolidinone (NMP), N , N -dimethylacetamide (DMAc), N , N -dimethylformamide (DMF), pyridine, cyclohexanone and tetrahydrofuran. The polymer films had tensile strength in the range of 79–103 MPa, an elongation at break in the range of 6–16%, and a tensile modulus in the range between 2.1 and 2.8 GPa. The glass transition temperatures of the polymers were determined by DMA method and they were in the range of 264–291 °C. The coefficients of thermal expansion (CTE) of PAIs were determined by TMA instrument and they were between 29 and 67 ppm °C −1 . These polymers were fairly thermally stable up to or above 438 °C, and lose 10% weight in the range of 446–505 °C and 438–496 °C, respectively, in nitrogen and air. These polymers had exhibited 80% transmission wavelengths which were in the range of 484–516 nm and their cutoff wavelengths were in between 418 and 434 nm. The PAIs with trifluoromethyl group have higher bulk density resulting in higher free volume and then lowering the dielectric constant.

A new diamine monomer containing noncoplanar methyl substitution, 2,2′-dimethyl-4,4′-bis(2-trifluoromethyl-4-aminophenoxy)biphenyl (DBTFAPB) was successfully synthesized and used in the preparation of a series of polyamides and polyimides by direct polycondensation with various aromatic dicarboxylic acids and tertacarboxylic dianhydrides. A new noncoplanar dicarboxylic acid monomer containing noncoplanar methyl substitution, 2,2′-dimethyl-4,4′-bis(2-trifluoromethyl-4-trimellitimidophenoxy)biphenyl (DBTFTPB) was also successfully synthesized by refluxing the diamine, DBTFAPB, with trimellitic anhydride in glacial acetic acid. A series of new poly(amide–imide)s were prepared directly from DBTFTPB with various diamines in N-methyl-2-pyrrolidinone (NMP). All the polymers exhibited excellent solubility in solvents, such as N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), pyridine, tetrahydrofuran (THF), cyclohexanone and γ-butyrolactone at room temperature or upon heating at 70 °C. Inherent viscosities of the polymers were found to range between 0.60 and 1.34 dL g−1. Gel permeation chromatography (GPC) of the polymers showed number-average and weight-average molecular weight up to 7.3×104 and 17.9×104, respectively. These polymers showed that the glass transition temperatures were between 230 and 265 °C, and the 10% mass loss temperatures were higher than 460 °C in nitrogen atmosphere. All the polymers could be cast into flexible and tough films from DMAc solutions. They had a tensile strength in the range of 82–124 MPa and a tensile modulus in the range of 1.9–2.9 GPa. These polymers exhibited low dielectric constants ranging from 2.87 to 4.03, low moisture absorption in the range of 0.29–3.20%, and high transparency with an ultraviolet–visible absorption cut-off wavelength in the 347–414 nm range.

Novel optically transparent and highly organo-soluble alicyclic polyimides derived from bulky alicyclic diamine containing trifluoromethyl group on either side, 1,1-bis[4(2-trifluoromethyl-4aminophenoxy)phenyl]-4-tert-butylcyclohexane (BTFAPBC), were prepared. All polymers showed excellent solubility in various organic solvents like N-methyl-2-pyrrolidinone (NMP), N,N-dimethyl acetamide (DMAc), N,N-dimethyl formamide (DMF), pyridine, cyclohexanone, and γ-butyrolactone. The cut-off wavelength and 80% transmission wavelength for polyimides ranged from 362 to 407 nm and 436 to 492 nia, respectively. Polyimides with alicyclic tert-butylcyclohexyl cardo and trifluoromethyl substituents exhibited low dielectric constants ranging from 3.38 to 4.07 (at 1 KHz). Inherent viscosities of the polyimides were found to be in the range of 0.52-1.00 dL·g -1 . Polyimides showed glass transition temperatures in the range of 231-262 °C, and possessed a coefficient of thermal expansion (CTE) of 66-79 ppm.°C -1 . Thermogravimetric analyses of the polyimides revealed high thermal stability and decomposition temperature more than 450 °C in nitrogen atmosphere. The 10% weight loss temperature was found to be in the range of 453-544 and 413-502 °C in nitrogen and air atmospheres, respectively. The polyimide films had a tensile strength ranging from 84 to 100 MPa. The elongation at break varied from 6 to 12% and the tensile modulus varied from 1.1 to 2.1 GPa.

Diblock copolymers of 5-(methylphthalimide)bicyclo[2.2.1]hept-2-ene (NBMPI) and 1,5-cyclooctadiene were synthesized by living ring-opening metathesis polymerization with a well-defined catalyst {RuCl2(CHPh)[P(C6H11)3]2}. Unhydrogenated diblock copolymers showed two glass transitions due to poly(NBMPI) and polybutadiene segments, such as two glass-transition temperatures at −86.5 and 115.3 °C for poly1a and −87.2 and 115.3 °C for poly1b. However, only one melting temperature could be observed for hydrogenated copolymers, such as 119.8 °C for poly2a and 121.7 °C for poly2b. The unhydrogenated diblock copolymer with the longer poly(NBMPI) chain (poly1a; temperature at 10% mass loss = 400 °C) exhibited better thermal stability than the one with the shorter poly(NBMPI) chain (poly1b; temperature at 10% mass loss = 385 °C). Two kinds of hydrogenated diblock copolymers, poly2a and poly2b, exhibited relatively poor solubility but better thermal stability than unhydrogenated diblock copolymers because of the polyethylene segments. Poly[(hydrochloride quaternized 2-norbornene-5-methyleneamine)-b-butadiene]-1 (poly3a) was obtained after the hydrolysis and quaternization of poly1a. Dynamic light scattering measurements indicated that the hydrodynamic diameters of the cationic copolymer (poly3a) in water (hydrodynamic diameter = 1580 nm without salt), methanol/water (4/96 v/v; hydrodynamic diameter = 1500 nm without salt), and tetrahydrofuran/water (4/96 v/v; hydrodynamic diameter = 1200 nm without salt) decreased with increasing salt (NaCl) concentration. The effect of temperature on the hydrodynamic diameter of hydrophobically modified poly3a was also studied. The inflection point of the hydrodynamic diameter of poly3a was observed at various polymer concentrations around 30 °C. The critical micelle concentration of hydrophobically modified poly3a was observed at 0.018 g dL−1. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2901–2911, 2006

A new diamine containing isopropylidene, methyl substituted arylene ether, and trifluoromethyl groups, 2,2-bis[4-(2-trifluoromethyl-4-aminophenoxy)-3,5-dimethylphenyl]propane (BTADP), was synthesized and used in preparation of a series of polyimides by direct polycondensation with various aromatic tetracarboxylic dianhydrides in N, N-dimethylacetamide (DMAc). All polymers derived from diamine (BTADP) with trifluoromethyl substituents were highly organosoluble in the solvents, like N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide, N,N-dimethylformamide (DMF), pyridine, chloroform, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), dichloromethane, cyclohexanone, and γ-butyrolactone at room temperature or upon heating at 70 °C. Inherent viscosities of the polyimides were found to range between 0.58 and 0.97 dL·g−1. These polyimides had glass transition temperatures between 256 and 307 °C, and their 10% mass loss temperatures ranged from 440 to 462 °C and 421 to 443 °C under nitrogen and air, respectively. These polyimides had low dielectric constants in the range of 2.84–3.09. All the polyimides could be cast into films from DMAc solutions and were thermally converted into color lightness, optically transparent, flexible, and tough polyimides. The polyimide films had a tensile strength in the range of 83–97 MPa and a tensile modulus in the range of 2.0–2.2 GPa. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5766–5774, 2004

Thermally induced molecular graft copolymerization of the zwitterionic monomer, N,N‘-dimethyl(methylmethacryloyl ethyl)ammonium propanesulfonate (DMAPS), with the ozone-preactivated poly(vinylene f...

A series of new soluble poly(amide–imide)s were prepared from the diimide-dicarboxylic acid, 2,2-bis[4-(4-trimellitimidophenoxy)phenyl]norbornane, and various diamines by the direct polycondensation in N-methyl-2-pyrrolidinone containing CaCl2, using triphenyl phosphite and pyridine as condensing agents. All the polymers were obtained in quantitative yields with inherent viscosities of 1.01–1.42 dL g−1. Gel permeation chromatography (GPC) of the polymers showed number-average and weight-average molecular weight up to 67,300 and 118,000, respectively. The poly(amide–imide)s were amorphous and were readily soluble in various solvents such as N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), pyridine, cyclohexanone and tetrahydrofuran. Tough and flexible films were obtained by casting their DMAc solution. The films had tensile strength of 89–110 MPa and a tensile modulus range of 1.8–2.2 GPa. The glass transition temperatures of the polymers were determined by DSC method and they were in the range of 265–295 °C. The polymers were fairly stable up to a temperature around or above 450 °C, and lose 10% weight in the range of 472–504 °C and 490–520 °C in nitrogen and air, respectively.

A new bis(ether anhydride), 1,1-bis[4-(3,4-dicarboxyphenoxy)phenyl] cyclododecane dianhydride (BDPCD), was prepared in three steps starting from nitrodisplacement of 4-nitrophthalonitrile with 2,2-bis(4-hydroxyphenyl) cyclododecane (BHPC), followed by alkaline hydrolysis of the dehydration of the resulting bis(ether diacid) (BCPPC) and subsequent dehydration of the resulting bis(ether diacid) (BAPPC). A series of new highly soluble poly(ether imide)s having tert-butyl substitutents, together with noncoplanar and pendent cardo groups were prepared from such bis(ether anhydride) (BDPCD) with various diamines by a conventional two-stage synthesis including the polyaddition and chemical cyclodehydration. The resulting poly(ether imide)s had inherent viscosities inthe range of 0.50-.0.86 dL.g -1 . The GPC measurement revealed that the polymers exhibited number-average and weight-average molecular weight up to 63 000 and 115 000, respectively. All the polymers showed typical amorphous diffraction patterns. All of the poly(ether imide)s showed excellent solubility and were readily dissolved in various solvents such as N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), pyridine, cyclohexanone and tetrahydrofuran. Most of the polymers could be dissolved in chloroform as high as 30wt.-% concentration. These polymers had glass transition temperatures (T g ) in the range of 230-262°C. Thermogravimetric analysis (TGA) showed that all polymers were stable, with 10% weights loss recorded above 434°C and 407°C in nitrogen and air, respectively. These transparent, tough and flexible polymer films could be obtained by solution casting from the DMAc solution. These polymer films had tensile strengths in the range of 80-102 MPa and tensile moduli in the range of 1.7-2.0 GPa.

In this article, three types of aromatic polyamides were prepared by the direct polycondensation of bis[4-(4-aminophenoxy) phenyl] diphenyl methane (BAPDM) with various of aromatic diacids such as terephthalic acid (TPAc), 5-tert-butylisophthalic acid (TBPAc), and 4,4′-hexafluoroisopropylidenedibenzoic acid (6FDAc). The pervaporation and vapor permeation performance of the above novel aromatic polyamide membranes for dehydrating an aqueous alcohol solution was investigated. Compared with pervaporation, vapor permeation effectively increases the perm-selectivity of water. Moreover, the effect of aromatic diacids on the polymer chain packing density, pervaporation, and vapor permeation performance was investigated. It was found that the permeation rate can be increased by introduction of a bulky group into the polymer backbone.

A new bis(ether anhydride), 3,3′,5,5′-tetramethyl-2,2-bis[4-(4-dicarboxyphenoxy)phenyl]propane dianhydride (3), was prepared in three steps: the nitro displacement of 4-nitrophthalonitrile with 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, the alkaline hydrolysis of the intermediate bis(ether dinitrile), and the subsequent dehydration of the resulting bis(ether diacid). A series of new highly soluble poly(ether imide)s with tetramethyl and isopropylidene groups were prepared from the bis(ether anhydride) 3 with various diamines by a conventional two-stage synthesis including polyaddition and chemical cyclodehydration. The resulting poly(ether imide)s had inherent viscosities of 0.54–0.73 dL g−1. Gel permeation chromatography measurements revealed that the polymers had number-average and weight-average molecular weights of up to 54,000 and 124,000, respectively. All the polymers showed typical amorphous diffraction patterns. All of the poly(ether imide)s showed excellent solubility and were readily dissolved in various solvents such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, pyridine, cyclohexanone, tetrahydrofuran, and even chloroform. Most of the polymers could be dissolved with chloroform concentrations as high as 30 wt %. These polymers had glass-transition temperatures of 244–282 °C. Thermogravimetric analysis showed that all polymers were stable, with 10% weight losses recorded above 463 °C in nitrogen. These transparent, tough, and flexible polymer films were obtained through solution casting from N,N-dimethylacetamide solutions. These polymer films had tensile strengths of 81–102 MPa and tensile moduli of 1.8–2.0 GPa. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2556–2563, 2002

A new bulky pendent bis(ether anhydride), 1,1-bis[4-(4-dicarboxyphenoxy)phenyl]-4-phenylcyclohexane dianhydride, was prepared in three steps, starting from the nitrodisplacement of 1,1-bis(4-hydroxyphenyl)-4-phenylcyclohexane with 4-nitrophthalonitrile to form bis(ether dinitrile), followed by alkaline hydrolysis of the bis(ether dinitrile) and subsequent dehydration of the resulting bis(ether diacid). A series of new poly(ether imide)s were prepared from the bis(ether anhydride) with various diamines by a conventional two-stage synthesis including polyaddition and subsequent chemical cyclodehydration. The resulting poly(ether imide)s had inherent viscosities of 0.50–0.73 dL g−1. The gel permeation chromatography measurements revealed that the polymers had number-average and weight-average molecular weights of up to 57,000 and 130,000, respectively. All the polymers showed typical amorphous diffraction patterns. All of the poly(ether imide)s showed excellent solubility in comparison with the other polyimides derived from adamantane, norbornane, cyclododecane, and methanohexahydroindane and were readily dissolved in various solvents such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, pyridine, cyclohexanone, tetrahydrofuran, and even chloroform. These polymers had glass-transition temperatures of 226–255 °C. Most of the polymers could be dissolved in chloroform in as high as a 30 wt % concentration. Thermogravimetric analysis showed that all polymers were stable up to 450 °C, with 10% weight losses recorded from 458 to 497 °C in nitrogen. These transparent, tough, and flexible polymer films could be obtained by solution casting from DMAc solutions. These polymer films had tensile strengths of 79–103 MPa and tensile moduli of 1.5–2.1 GPa. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2066–2074, 2002

A new triphenylamine-containing diamine monomer, 4,4‘-diamino-3‘ ‘,4‘ ‘-dimethyltriphenylamine (DADT), was successfully synthesized by the cesium fluoride-mediated condensation of 3,4-dimethylaniline with 4-fluoronitrobenzene, followed by reduction. The monomer was reacted with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides to produce a series of novel polyamides and polyimides, respectively. A new triphenylamine-containing dicarboxylic acid monomer, 4,4‘-trimellitimido-3‘ ‘,4‘ ‘-dimethyltriphenylamine (TDT), was successfully synthesized by refluxing the diamine, DADT, with trimellitic anhydride in glacial acetic anhydride. A series of new poly(amide−imide)s were prepared from TDT with various diamines by the direct polycondensation. The polymers were obtained in quantitative yields with inherent viscosities of 0.61−2.28 dL g-1. Most of the polymers dissolved in N-methyl-2-pyrrolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, pyridine, and cyclohexanone. Th...

Photophysical and solution properties of pyrene-labeled poly(3-dimethyl(methylmethacryloyl ethyl) ammonium propane sulfonate), poly(DMAPS/Py), were studied in terms of fluorescence emission measurement. The I E /I M was shown as a function of polymer concentration in deionized water. I E /I M value decreases with an increase in the salt concentration. The addition of surfactants to the aqueous solution of poly(DMAPS/Py) can either induce the mixed micelle of intra- polymer and its surrounding surfactants and/or mixed micelle of inter-polymers and their surrounding surfactants. Models of interactions between poly(DMAPS/Py) and surfactant or divalent salt in aqueous solution are proposed.

Single-walled carbon nanotubes (SWCNTs) demonstrate a high efficiency as optical elements for mode-locking in fiber lasers. A thin polymer film with dispersed nanotubes is a suitable approach to insert the element into the laser resonator. The main problem is that the polymer oxidative destruction temperature is much lower than that for SWCNTs. To form polymer–nanotube composites with a high threshold of thermal degradation, surviving under the relatively intense laser beams, a set of polyimides has been used. It has been shown that for the synthesized polyimides the temperature of degradation was in the range 500–530 °C, depending on the polymer. In the near-infrared range the polyimides were transparent, and the main absorption bands were detected at wavelengths less than 400 nm. A procedure of the fabrication of composite SWCNT/polyimide films was developed. The films were formed on transparent substrates, as quartz and glass slides.

A new bulky pendent bis(ether anhydride), 1,1-bis[4-(4-dicarboxyphenoxy)phenyl]-4- tert -butylcyclohexane dianhydride ( 3 ), was prepared in three steps starting from nitro-displacement of 1,1-bis(4-hydroxyphenyl)-4- tert -butylcyclohexane with 4-nitrophthalonitrile to form bis(ether dinitrile) ( 1 ), followed by alkaline hydrolysis of the bis(ether dinitrile) and subsequent dehydration of the resulting bis(ether diacid). A series of new poly(ether imide)s were prepared from such bis(ether anhydride) ( 3 ) with various diamines by a conventional two-stage synthesis including the polyaddition and subsequent chemical cyclodehydration. The resulting poly(ether imide)s had inherent viscosities in the range of 0.50–0.79 dl g −1 . The GPC measurement revealed that the polymers exhibited number-average and weight-average molecular weight up to 64,000 and 142,000, respectively. All the polymers showed typical amorphous diffraction patterns. All of the poly(ether imide)s showed excellent solubility and were readily soluble in various solvents such as N -methyl-2-pyrrolidinone, N,N -dimethylacetamide (DMAc), N,N -dimethylformamide, pyridine, cyclohexanone, tetrahydrofuran and even in chloroform. These polymers had glass transition temperatures in the range of 227–266°C. Most of the polymers could be dissolved in chloroform of as high as 30 wt% concentration. Thermogravimetric analysis showed that all polymers were stable up to 450°C, with 10% weight loss recorded in the range of 470–515°C in nitrogen. These transparent, tough and flexible polymer films could be obtained by solution cast from the DMAc solution. These polymer films had tensile strength in the range of 79–98 MPa and tensile modulus in the range of 1.8–2.0 GPa.

A new hexafluoro-containing diamine monomer, 2,2-bis[4-(4-aminophenoxy)-3,5-dimethylphenyl]-bexafluoropropane (TBAPHP), was synthesized in three steps, starting from hexafluoroacetone sesquihydrate and 2,6-xylenol. The monomer was reacted with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides to produce a series of polyamides and polyimides, respectively. The polyamides were prepared under Yamazaki reaction conditions. The polyimides were prepared by a two-stage procedure that included a ring-opening polyaddition yielding poly(amic acid)s, followed by a cyclodehydration to polyimides. The obtained polymers had inherent viscosities of 0.52-0.82 dL.g -1 . All of the polymers dissolved in polar solvents, such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide, and N,N-dimethyl-formamide. The polyimides derived from 4,4'-oxydiphthalic anhydride and 3,3',4,4'-benzophenonetetracarboxylic dianhydride exhibited an excellent solubility and were dissolved in cyclohexanone, pyridine, tetrahydrofuran, and chloroform. These polymers showed glass transition temperatures of 231-301 °C and decomposition temperatures at 10% weight loss ranging from 470 to 495 °C in nitrogen and from 473 to 505 °C in air. The tough and flexible polymer films obtained from solution casting showed tensile strengths of 78-96 MPa and tensile moduli of 2,0-2,4 GPa. Polymers containing methyl substituents had higher solubilities and T g values than those without methyl substituents. In addition, the bexafluoroisopropylidene containing polymers exhibited a higher solubility and thermal stability than those containing isopropylidene units. UV-visible absorption spectra revealed that the polyimides showed a better transparency than the polyamides.

Two new bis(ether anhydride)s, 2,2'-dimethyl-4,4'-bis[4-(3,4-dicarboxyphenoxy)]biphenyl dianhydride (4A) and bis[4-(3,4-dicarboxy phenoxy)phenyl]diphenylmethane dianhydride (4B), were prepared in three steps starting from nitrodisplacement of 4-nitrophthalonitrile with 2,2'-dimethylbiphenyl-4,4'-diol and bis(4-hydroxyphenyl)diphenylmethane, respectively, followed by alkaline hydrolysis of the intermediate bis(ether dinitrile)s and subsequent dehydration of the resulting bis(ether diacid)s. A series of new highly organosoluble poly(ether imide)s were prepared from the bis(ether anhydride)s and various diamines by conventional two-stage synthesis. The resulting poly(ether imide)s had inherent viscosities in the range of 0.55-0.81 dL.g -1 . GPC measurement revealed that the polymers exhibited number-average molecular weight and weight-average molecular weight up to 45 000 and 82 000, respectively. All the polymers showed typical amorphous diffraction patterns. Almost all the poly(ether imide)s showed excellent solubility and readily dissolved in various solvents such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, pyridine, cyclohexanone, tetrahydrofuran, and chloroform. These polymers had glass transition temperatures in the range of 224-256 °C. Thermogravimetric analysis showed that all polymers were stable, with 10% weight loss recorded above 489 °C in nitrogen. The isothermal gravimetric analysis results demonstrated that these poly(ether imide)s showed weight losses of 7.0-10.5% after isothermal aging at 350 °C in static air for 20 h. These tough and flexible polymer films could be easily obtained by solution cast from the DMAc solution. These polymer films had tensile strength of 84-116 MPa and tensile modulus of 1.9-2.7 GPa.

A new cardo diamine monomer, 1,1-bis [4-(4-aminophenoxyl) phenyl]-4-phenylcyohexane bearing a 4-phenylcyclohecylidene unit, was prepared in three steps from -4phenylcyoheanone. The monomer was reacted with various aromatic dicatboxilic acids and tetracarboxylic dianhydrides to produce novel polyamides and polyamides, respectively. The polyamides were prepared utizing Yamazaki reaction conditions with inherent viscosities of 0.62-0.98 dL . g -1 . The polyamides were prepared by a two-stage procedure that included a ringopening polyaddition to give poly(amic acids)s, followed by thermal or chemical cyclodehydration. By chemical cyclodehydratation, the obtained polyimides had inherent viscosities of 0.61-0.93 dL . g -1 . Most of the polymers dissolved in N,N-dimethylformamide dimethyl sulfoxide, pyridine, and cyclohexanone. These polymers showed glass transition temperatures between 225-312°C and decomposition temperatures at 10% weight loss temperatures ranging from 470-500°C and 480-510°C in nitrogen and air atmosphere, respectively. These tough and flexible polymer films had a tensile strenght of 81-124 MPa, an elongation at break of 8-21%, and tensile modulus of 2.0-2.8 GPa.

A series of new linear polyaspartimides was obtained via a Michael addition reaction from bis(3-ethyl-5-methyl-4-maleimidophenyl)methane (BEMM) with various aromatic diamines in m -cresol in a 1:1 molar ratio. The molecular weight and yield of these polymers tend to increase with increasing monomer concentration. It was observed that a maximum molecular weight was reached at around 0.72 mol l −1 of monomer concentration. Both the yield and the molecular weight of the polymers increased with reaction times up to around 100 h. The inherent viscosities of the polymers varied from 0.42 to 0.70 dl g −1 . The polymers had number-average molecular weight and weight-average molecular weight in the range of 9400–20 000 and 24 000–68 000, respectively. All polymers are amorphous and soluble in N -methyl-2-pyrrolidone, N,N -dimethylacetamide, DMF, dimethyl sulfoxide, pyridine, m -cresol, cyclohexanone and tetrahydrofuran. The polymers had high glass transition temperatures in the range of 242–308°C and good thermal stability — 10% weight loss temperatures in the range of 408–459°C in air and 396–421°C in nitrogen.

A series of new soluble poly(amide-imide)s were prepared from the diimide-dicarboxylic acid 2,2-bis[4-(4-trimellitimidophenoxy)phenyl]hexafluoropropane with various diamines by direct polycondensation in N-methyl-2-pyrrolidinone containing CaCl2 with triphenyl phosphite and pyridine as condensing agents. All the polymers were obtained in quantitative yields with inherent viscosities of 0.52–0.86 dL · g−1. The poly(amide-imide)s showed an amorphous nature and were readily soluble in various solvents, such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, pyridine, and cyclohexanone. Tough and flexible films were obtained through casting from DMAc solutions. These polymer films had tensile strengths of 71–107 MPa and a tensile modulus range of 1.6–2.7 GPa. The glass-transition temperatures of the polymers were determined by a differential scanning calorimetry method, and they ranged from 242 to 279 °C. These polymers were fairly stable up to a temperature around or above 400 °C, and they lost 10% of their weight from 480 to 536 °C and 486 to 537 °C in nitrogen and air, respectively. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3498–3504, 2001

A new dicarboxylic acid containing a diphenylmethylene linkage, bis[4-(4-carboxyphenoxy)phenyl]diphenylmethane (BCAPD), was prepared from bis(4-hydroxphenyl)diphenylmethane and p-fluorobenzonitrile via an aromatic nucleophilic substitution reaction followed by hydrolysis. A series of novel polyamides were prepared by the direct polycondensation of BCAPD and various aromatic diamines. The polymers were produced with moderate to high inherent viscosities of 0.80–0.85 dL g−1. Nearly all the polymers were readily soluble in polar solvents such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide, in less polar solvents such as pyridine and cyclohexanone, and in tetrahydrofuran. All the polymers were amorphous, and the polyamide films had a tensile strength and a tensile modulus greater than 80 MPa and 2.0 GPa, respectively. These polyamides had glass-transition temperatures between 249 and 274 °C, and their temperatures at a 10% weight loss were 477–538 and 483–540 °C in nitrogen and air atmospheres, respectively. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1156–1161, 2001

A dicarboxylic acid monomer, 5-phthalimidoisophthalic acid, containing a phthalimide pendent group was prepared by the condensation of 5-aminoisophthalic acid and phthalic anhydride in glacial acetic anhydride. The monomer was reacted with various aromatic diamines to produce polyamides using triphenyl phosphite and pyridine as condensing agents. These polyamides were produced with inherent viscosities of 0.64-1.14 dL g 1 . All the polymers, characterized by wide-angle X-ray diffraction, revealed an amorphous nature resulting from the presence of the bulky pendent group. These polyamides exhibited excellent solubility in a variety of solvents such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, dimethyl sulfoxide, pyridine, and cyclohexanone. These polyamides showed glass-transition temperatures (T g 's) between 247 and 273 °C (by DSC) and 248 and 337 °C (by a dynamic mechanical analyzer). The thermogravimetric analytic measurement revealed the decomposition temperature at 10% weight-loss temperatures (Td 10 ) ranging from 442 to 530 °C in nitrogen. The polyamides containing phthalimide groups exhibited higher T g and Td 10 values than those having no phthalimide groups. Transparent, tough, and flexible films of these polyamides could be cast from the DMAc solutions. These casting films had tensile strengths ranging from 81 to 126 MPa, elongations at break ranging from 7 to 13%, and tensile moduli ranging from 2.0 to 2.9 GPa.

A new cardo diamine monomer, 1,1-bis[4-(4-aminophenoxy)phenyl]-4-tert-butylcyclohexane containing tert-butylcyclohexylidene units was prepared in three steps from 4-tert-butylcyclohexanone. The monomer was reacted with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides to produce polyamides and polyimides, respectively. All the polymers, characterized by X-ray diffraction, are amorphous. These cardo polymers exhibit good solubility in a variety of solvents. Almost all polymers are soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), pyridine, and even in tetrahydrofuran (THF) and cyclohexanone. The polymers show glass transition temperatures between 244-310°C. and decomposition temperatures at 10% mass loss ranging from 486-526°C in nitrogen. The tough and flexible polymer films have tensile strength of 77-137 MPa, elongations at breaks of 5-14% and tensile moduli of 2.0-2.6 GPa.

The ring-opening metathesis polymerization (ROMP) of 5-(methyl methacryloyl isocyanate)bicyclo[2.2.1]hept-2-ene [i.e., norbornene containing methacryloyl isocyanate (NBMMAI)] having cyclic olefin and terminal double bond was investigated in order to produce novel polymers with cross-linkable side chains under ligand exchange with MMA by using {RuCl2(CHPh)[P(C6H11)3]2} (II) as catalyst. Results of infrared spectra, 1H NMR, and 13C NMR showed that poly(NBMMAI) contains polynorbornene backbone ring structure and methacryloyl side chains. The 1H NMR spectrum of poly(NBMMAI) showed new vinyl protons as a broad signal between 5.15 and 5.37 ppm in the ratio of 0.4 and 2.8, corresponding to the vinyl protons of the cis and trans double bond of the ring-opened polymer, respectively. Gel formation was still observed in the polymerization of NBMMAI using ruthenium catalyst II with 20 mol % p-methoxyphenol (MEHQ). An increase in bulkiness of the ligand reduced the cross metathesis reaction and led to reduced activity...

Different types of sulfobetaines and their corresponding cationic monomers and polymers derived from N,N-dialkylamino phenyl methacrylamide have been synthesized for this study. Comparing the chemical shifts in 1 H and 13 C NMR of the methylene groups in the cationic monomers and betaines reveal that the respective methylene groups are clearly distinguishable from each other. Results obtained from the intrinsic viscosity for zwitterionic poly(DEMAPhAPS) are opposite to that for the corresponding cationic poly(DEMMAPhAMS).

A new dicarboxylic acid monomer, 1,1-bis[4-(4-carboxyphenoxy)phenyl]-4-tert-butylcyclohexane, bearing a pendent tert-butylcyclohexylidene group was prepared in three steps from 4-tert-butylcyclohexanone. The monomer was reacted with various diamines to produce a series of new polyamides with triphenyl phosphite and pyridine as condensing agents. These polyamides were produced with inherent viscosities of 0.74 to 1.02 dL g−1. All the polymers were characterized by X-ray diffraction that revealed this amorphous nature. These polymers exhibited excellent solubility in a variety of solvents. Almost all the polymers could be dissolved in N-methyl-2-pyrrolidinone, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, dimethyl sulfoxide, pyridine, and even in tetrahydrofuran and cyclohexanone. These polymers showed glass-transition temperatures between 223 and 256 °C and decomposition temperatures at 10% weight loss ranging from 468 to 491 °C and 469 to 498 °C in nitrogen and air atmospheres, respectively. Transparent, tough, and flexible films of these polymers were cast from the DMAc solutions. These polymer films had tensile strengths ranging from 76 to 99 MPa, elongations at break from 7 to 19%, and initial moduli from 2.1 to 2.7 GPa. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 797–803, 2000

The separation of aqueous alcohol mixtures was carried out using a series of poly(3-alkylthiophene) membranes. The poly(3-alkylthiophene) polymers were prepared by oxidative polymerization in the presence of anhydrous FeCl3 in dry chloroform. The effect of the alkyl group structure of the poly(3-alkylthiophene) membrane on the thermal properties and the pervaporation performances were investigated. The solubility of ethanol in the poly(3-alkylthiophene) membrane is higher than that of water, however, the diffusivity of water through the membrane is higher than that of ethanol. In addition, the effects of the feed composition and the degree of swelling on the pervaporation performances of the poly(3-alkylthiophene) membranes were also studied. q 1999 Elsevier Science Ltd. All rights reserved.

The pervaporation and vapor permeation performances of a series of fluorine-containing aromatic polyamide membranes for various alcohol mixtures were investigated. Compared with pervaporation, vapor permeation effectively increases the permselectivity of water. The solubility of alcohol in an aromatic membrane is higher than that of water, but the diffusivity of water across the membrane is higher than that of the alcohols. In addition, the relationship between the polymer structure and pervaporation performance was obtained. It was found that the permeation rate can be increased by the introduction of bulky substituted groups and arylene ether groups into the polymer backbone.