Synthesis and properties of new poly(amide-imide)s based on 2,5-bis(trimellitimido)toluene

Summary A series of new aromatic poly(amide-imide)s were synthesized by the triphenyl phosphite activated polycondensation of the diimide-diacid, 2,5-bis(trimellitimido)toluene (I) with various aromatic diamines. The poly(amide-imide)s had inherent viscosities of 0.69–1.89 dL/g. Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents. Transparent, flexible, and tough films of these polymers could be cast from DMAc or NMP solutions. Their cast films had tensile strengths ranging from 76 to 112 MPa, elongations at break from 8 to 31%, and initial moduli from 2.20 to 2.99 GPa. The glass transition temperatures of these polymers were in the range of 253–328°C. Received: 25 September 1998/Revised version: 2 December 1998/Accepted: 8 December 1998     

Colorimetric chemosensor for Ni2+ based on alizarin complexone and a cationic polyelectrolyte in aqueous solution

A new and convenient chemosensor for detecting Ni²⁺ in aqueous buffer has been developed by mixing an anionic organic dye, alizarin complexone (ALC) and a cationic polyelectrolyte, poly(diallyldimethylammonium chloride) (PDADMAC). After addition of Ni²⁺, the chemosensor exhibits a remarkable bathochromic shift with a significant color change from red to blue, while other metal ions did not induce such a change. The color change may be attributed to the aggregate formation of an ALC-based Ni²⁺ complex on the surface of PDADMAC. The results showed that the ALC and PDADMAC mixture can be applied to detect Ni²⁺ selectively with colorimetric changes. This investigation can lead to the construction of new chemosensors by facile and simple mixture of a water-soluble dye and an oppositely charged polyelectrolyte. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47496.     

Clickable,versatile poly(2,5-dithienylpyrrole) derivatives

In this study a novel, clickable, azide containing conducting polymers based on 1-(2-azido-ethyl)-2,5-dithiophene-2-yl-1H-pyrrole (SNS-N₃) were synthesized and characterized. Optical and electronic properties of homopolymer (PSNS-N₃) were investigated and colorimetric studies were performed. The homopolymer has a band gap of 2.49 eV and it displays yellow to blue coloration upon doping. Electrochemically prepared copolymers of SNS-N₃ and 3,4-ethylenedioxythiophene (EDOT) formed multichromic, color tunable electrochromic materials with continuous color gradient from cinnamon, mustard, lime green, blue and dark blue. Spectroelectrochemical analyses revealed that the neutral copolymers possess two absorption maxima (～320 and 450 nm) where the relative intensity and position of the two depends on polymerization potential. Copolymer films could be fully switched between their neutral and oxidized forms in ～1.2 s with a percent transmittance of ～65% at 950 nm. Moreover, a PSNS-N₃ coated ITO electrode was subjected to click reaction using ethynylferrocene. CV and FTIR studies revealed that ferrocene could easily be attached onto the electrode surface without loss of electroactivity of both ferrocene and PSNS backbone. Our results suggest that electrochemically prepared PSNS-N₃ films offer a novel and multipurpose platform for simple, effective post-functionalization of poly(2,5-dithienylpyrrole)s under mild conditions.     

Biobased poly(butylene 2,5-furandicarboxylate) and poly(butylene adipate-co-butylene 2,5-furandicarboxylate)s: From synthesis using highly purified 2,5-furandicarboxylic acid to thermo-mechanical properties

To synthesize high quality (co)polyesters derived from 2,5-furandicarboxylic acid (FA), an acetic acid refluxing/pH-swing method was proposed to purify FA. 2-Carboxyl furfural and other impurities were removed completely from FA with this method. Using highly purified FA, biobased polyester poly(butylene furnadicarboxylate) (PBF) and aliphatic-aromatic copolyesters poly(butylene adipate-co-butylene 2,5-furandicarboxy-late)s (PBAFs) were synthesized via melt (co)polycondensation. The (co)polyesters were characterized with GPC, FTIR, ¹H NMR, DSC and TGA, and their tensile mechanical properties were also assessed. The copolyesters possess random chain structure, monomer feed ratio-controlled copolymer composition and excellent thermal stability (T_d,5% > 340 °C) in full composition range. Both BA-rich and BF-rich PBAFs are crystalline polymers. The crystallizability decreases with composition, up to nearly amorphous at moderate ?_BF (40–60%). PBAFs with ?_BF no more than 50% exhibit obvious high-elastic deformation and rebound resilience, and possess tensile properties (E 18–160 MPa, σ_b 9–17 MPa, ε_b 370–910%) comparable to poly(butylene adipate). PBAFs with higher ?_BF behave like nonrigid plastics with low tensile moduli (42–110 MPa), moderate strength (30–42 MPa) and high elongation at break (310–470%). In comparison, PBF is a strong and tough thermoplastic having balanced mechanical properties, namely, much higher tensile modulus (1.9 GPa) and strength (56 MPa) and high elongation at break (260%). It seems necessary and effective to use highly purified FA for synthesizing high performance FA-derived (co)polyesters.     

Synthesis and characterization of new organo-soluble poly(amide-imide)s based on 1,4-bis(trimellitimido)-2,5-dimethylbenzene

Summary A series of new aromatic poly(amide-imide)s were synthesized by the triphenyl phosphite activated polycondensation of the diimide-diacid, 1,4-bis(trimellitimido)-2,5-dimethylbenzene (I), with various aromatic diamines. The poly(amide-imide)s had inherent viscosities of 1.13–2.22 dL/g. Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents. Transparent, flexible, and tough films of these polymers could be cast from DMAc or NMP solutions. Their cast films had tensile strengths ranging from 64 to 116 MPa, elongations at break from 6 to 20%, and initial moduli from 2.18 to 3.90 GPa. The glass transition temperatures of these polymers were in the range of 247–324°C. Received: 13 April 1999/Revised version: 28 May 1999/Accepted: 26 June 1999     

Some properties of organosoluble poly(2,5-didodecyloxy-p-phenylenevinylene) and its blends with poly(oxyethylene)

An organosoluble precursor of poly(2,5-didodecyloxy-p-phenylenevinylene) (PDDOPV) with high molecular weight was synthesized via the chlorine precursor route and characterized by IR and UV-Vis spectra, GPC, DSC, and elemental analysis. Factors effecting the thermal elimination reaction were studied. The solubility, absorption spectra and photoluminescence spectra of PDDOPV were also investigated. The conductivity of PDDOPV doped with different dopants (I₂, Br₂, FeCl₃ and H₂SO₄) and the I₂-doped conductivity of PDDOPV/PEO (polyoxyethylene) blends and PDDOPV/PEO/LiClO₄ blends were compared. The results showed that a synergistic mixed conductivity existed in the I₂-doped PDDOPV/PEO/LiClO₄ blend.     

Thermal analysis of poly(1,3,4-oxadiazole-2,5 diyl-1,2-ethenediyl) and poly(1,4-phenylene-1,3,4-oxadiazole-2,5 diyl-1,2 ethendiyl)

Poly(1,3,4-oxadiazole-2,5-diyl-1,2-ethendiyl) and poly(1,4-phenylene-1,3,4-oxadiazole-2,5 diyl-1,2-ethenediyl) have been prepared by condensation polymerization using fuming sulfuric acid and different quantities of terephthalic acid (T), fumaric acid (F), and hydrazine sulfate (HS). Homopolymers of F and T and various copolymers of F:T have been prepared. The polymer structure was investigated by IR and visible-range spectra and elemental analysis. The existence of poly(1,3,4-oxadiazole-diylphenylene) and poly(hydrazoterephthaloyl) structures was revealed by these studies. These polymers were thermally stable, and most of them did not show a weight loss below 350°C. The relative thermal stabilities of the various polymers have been evaluated by “integral procedural decomposition temperature” and activation energy measurements.     

Electrochemical preparation of poly(2,5-dimethoxy-1,4-phenylene)

Summary p-Dimethoxybenzene was electro-oxidatively polymerized to give poly(2,5-dimethoxy-1,4-phenylene) with high yield. 1,4-Structure of polyphenylene was confirmed by ¹³C-NMR and IR spectrum. The polymer was deposited on electrode, and electrolysis solvent affected the polymer yield and morphology of the polymer. In a strongly basic solvent the polymerization was inhibited, which suggests that cation radical of p-dimethoxybenzene is an active species of this polymerization.     

Synthesis and crystallinity of poly(butylene 2,5-furandicarboxylate)

Poly(butylene 2,5-furandicarboxylate) (PBF) was obtained by esterification of 2,5-furandicarboxylic acid (FDCA) and 1,4-butylene glycol (BG). By using ¹H NMR at 750 MHz to recognize the trace end groups at different polymerization stages, the study provides a clear picture that the polymerization proceeds cleanly to give the desirable linear structure. On the basis of the end group analysis, the degree of polymerization of PBF was determined to be as high as 125, which is in agreement with the molecular weight from the viscosity study. Solid state ¹³C NMR revealed that one of the furan carbons is sensitive to local morphology. DSC and X-ray diffraction further revealed that the polymer had high tendency to form crystalline materials (T_m = 130 °C & 169 °C; T_g = 32 °C). On the basis of DSC and NMR evidences, the two crystalline states are assumed to be β-phase (less stable) and α-phase (more stable), respectively, by analogy with the crystalline structure of PBT. High tendency of forming crystalline structure allows the continuous fibers to be drawn from the PBF's melt. The results thus raise the hope that the biomass-derived PBF could be a promising furan counterpart of the petroleum-based poly(butylene terephthalate) (PBT).     

Gas permeation properties of poly(2,5-dialkyl-p-phenyleneethynylene) membranes

Dipropynylbenzenes with alkyl groups (CH₃C ≡ CRC₆H₂RC≡CCH₃, R=n-C₆H₁₃, n-C₈H₁₇, n-C₁₀H₂₁, 1a–c, respectively) were polymerized with Mo(CO)₆ to afford solvent-soluble poly(2,5-dialkyl-p-phenyleneethynylene)s (2a–c). The polymers (2a–c) had high molecular weight over 3×10⁴, and gave free-standing membranes by solution casting method. According to thermogravimetric analysis (TGA), these poly(p-phenyleneethynylene)s showed high thermal stability (T₀ ≥380 °C). The densities of membranes of poly(2,5-dialkyl-p-phenyleneethynylene)s (2a–c) were 0.936–0.965, and their fractional free volume (FFV) were relatively large (ca. 0.14–0.15). The oxygen permeability coefficients (PO₂) of membranes of 2a–c were 4.88, 7.06, and 16.6 barrers, respectively.     

Ratiometric fluorescent chemosensor based on the block copolymer of poly(N-isopropylacrylamide)-b-poly(N-vinylcarbazole) containing rhodamine 6G and 1,8-naphthalimide moieties

We have synthesized an amphiphilic block copolymer poly(N-isopropylacrylamide)-b-poly(N-vinylcarbazole) containing 1,8-naphthalimide and spirolactam rhodamine 6G moieties via reversible addition-fragmentation chain transfer radical polymerization. The photoluminescence (PL) spectrum of the poly(N-vinylcarbazole) block well matches the absorption spectrum of the 1,8-naphthalimide moiety and the enhanced emission with a peak at 510 nm from the 1,8-naphthalimide moiety is found in the block copolymer film for excitation at 330 nm. The 560-nm emission from the rhodamine 6G moiety is observed as the block copolymer film sprayed by Britton-Robinson (B-R) buffers or Fe³⁺ aqueous solutions for excitation at 330 and 400 nm. The PL intensity at 560 nm is markedly increased for the pH value of the B-R buffer lower than 3.0 or the Fe³⁺ concentration in water higher than 5 × 10⁻⁴ M. The 560-nm PL intensity is much higher for the block copolymer film photoexcited at 330 nm than that photoexcited at 400 nm due to double-step resonance energy transfer. The PL intensity ratio of 560 to 510 nm (I₅₆₀/I₅₁₀) is dependent on the resonance energy transfer from 1,8-naphthalimide to rhodamine 6G, which is sensitive to the concentrations of H⁺ and Fe³⁺ ions in water.     

Thermal degradation of poly(2-methylphenylene oxide), poly(2,5-dimethylphenylene oxide) and poly(1,4-phenylene oxide)

Polyoxyphenylenes were obtained from phenol, 2-methylphenol, 2,5-dimethyl-phenol in oxidative polycondensations using dimethylpyridineCuCl complexes as catalysts. Samples of polymers from polycondensations were not completely linear as found by i.r. analysis. The m.s. and c.c.—m.s. analysis of degradation products of poly(2-methylphenylene oxide) (PMPO) and poly(2,5-dimethylphenylene oxide) (P2, 5DMPO) have shown that both polymers undergo Fries-type rearrangement prior to statistical scission of benzyl bonds. Ether linkages of poly(1,4-phenylene oxide) (PPO) decompose without rearrangement though cyclization to benzofurane systems has been observed.     

A new selective fluorescent chemosensor for Cu(II) ion based on zinc porphyrin-dipyridylamino

A new fluorescent chemosensor 5-(p-N,N′-bis(2-pyridyl)amino)phenyl-10,15,20-tris(p-methoxyphenyl)porphyrin zinc has been designed and synthesized by the Ullmann-type coupling. It displays high selectivity for Cu²⁺ ion and exhibits fluorescence quenching upon binding of Cu²⁺ ion with an “on–off” type fluoroionophoric switching property, and its fluorescence can be revived by addition of EDTA disodium solution.     

Lithium secondary cells using LiX (X=ClO4, BF4) as electrolyte and poly(2,5-pyrrolylene) and poly(2,5-thienylene) as materials for positive electrodes

Repeated charge-discharge cycles of lithium secondary cells using poly(2,5-pyrrolylene) and poly(2,5-thienylene) on carbon fibre plates as the materials for positive electrodes have been tested. When the Li|LiBF₄|poly(2,5-pyrrolylene) secondary cell is charged and discharged at 0.1 mA cm^–2, it gives 91% current efficiency and 70% energy efficiency with an average discharging voltage of 2.75 V at the 9th charge-discharge cycle. This secondary cell has a theoretical energy density of 135 kW kg^–1 based on the energy stored and the weights of poly(2,5-pyrrolylene) and the active materials. The Li|LiClO₄|poly(2,5-thienylene) secondary cells show somewhat lower current efficiency and energy efficiency at the 9th charge-discharge cycle. The lithium cells using the polymers are rechargeable more than 50 times, but after about 50 cycles considerable lowering of the current efficiency and energy efficiency of the cells is observed, presumably due to degradation of the polymer.     

On the complex electrical conductivity of poly(2,5-furandiylvinylene)

Summary The presented paper deals with the ac-conductivity of undoped and doped poly(2,5-furandiylvinylene) (PFV). It is shown that the electrical conductivity as a complex physical quantity has to be splitted into a real and an imaginary part. Both parts depend on frequency, temperature, type and concentration of doping agents, and external pressure applied to the test specimens.     

Mechanical properties in torsion for poly(butylene terephthalate) and a poly(ether ester) based on poly(ethylene glycol) and poly(butylene terephthalate)

The torsional behavior of poly(ether ester) (PEE) thermoplastic elastomer, based on poly(ethylene glycol) (PEG) and poly(butylene terephthalate) (PBT) was studied and compared with that of PBT itself. Two types of experiments were performed: (1) stress relaxation in torsion, and (2) measurement of intermittent couple-twist responses. It was shown that the relaxation of the torsional couple M could be represented as a sum of several exponential terms in the time, rather than as a simple exponential function. This sum might be called a Prony series on the analogy of the usual stress relaxation which occurs after stretching a sample to a certain deformation and holding it constant. The intermittent couple-twist experiments were carried out by analogy with similar experiments in elongation. For PEE the couple rises steadily with the twist, whereas for PBT it rises abruptly and remains constant within the experimental error for high twists. The residual twist, however, showed a similar trend for both PEE and PBT. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 495–502, 1998     

Synthesis and properties of new poly(amide‐imide)s based on 2,5‐bis(trimellitimido)chlorobenzene

A series of new aromatic poly(amide‐imide)s were synthesized by the triphenyl phosphite‐activated polycondensation of the diimide‐diacid, 2,5‐bis(trimellitimido)chlorobenzene (I) with various aromatic diamines in a medium consisting of N‐methyl‐2‐pyrrolidone (NMP), pyridine, and calcium chloride. The poly(amide‐imide)s had inherent viscosities of 0.76–1.42 dL g⁻¹. The diimide‐diacid monomer (I) was prepared from 2‐chloro‐p‐phenylenediamine with trimellitic anhydride. Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents, including NMP and N,N‐dimethylacetamide. Transparent, flexible, and tough films of these polymers could be cast from N,N‐dimethylacetamide or NMP solutions. Their cast films had tensile strengths ranging from 74 to 95 MPa, elongations at break from 7 to 11%, and initial moduli from 1.38 to 3.25 GPa. The glass transition temperatures of these polymers were in the range of 233°–260°C, and the 10% weight loss temperatures were above 450°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1691–1701, 1999     

Electrical conductivity of polyblends of poly(1,4-phenylene vinylene) and poly(2,5-dimethoxy-1,4-phenylene vinylene)

Summary A series of polyblends of poly(1,4-phenylene vinylene), PPV, and poly(2,5-dimethoxy-1,4-phenylene vinylene), PDMPV, were prepared in film form from precursor polyblends of the respective sulfonium salt polymers, which were separately prepared from the respectivebis(sulfonium salt) monomers. The blend films were doped with I₂ at room temperature to obtain a wide range of electrical conductivities (10^–2 to 10²Scm^–1) depending on the blend composition. The higher the content of PDMPV in the blends the higher was the conductivity.     

Doped poly (2,5‐dimethyl aniline) for the detection of ethanol

Poly (2,5‐dimethyl aniline) (P25DMA), with and without NiO and ZnO as dopants, is evaluated as a sensing material for ethanol to detect transdermal ethanol emissions. Three sensing materials—P25DMA, P25DMA doped with 20 wt % NiO, and P25DMA doped with 20 wt % ZnO—are eventually deposited onto a radio frequency identification sensor. The limit of detection for the materials is found to be 3, 24, and 420 ppm, respectively. Also, all three sensing materials are selective toward ethanol with benzene and methanol used as interferents. The response and recovery times are also measured for the three sensing materials and are in the order of seconds, which is acceptable for a transdermal ethanol sensor. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42259.     

Synthesis and properties of sulfonated poly(2,5-diphenethoxy-p-phenylene)

A novel regio-controlled poly(2,5-diphenethoxy-p-phenylene) partially functionalized with sulfonic acids has been developed for a proton exchange membrane. Poly(2,5-diphenethoxy-p-phenylene) was prepared via the oxidative-coupling polycondensation using iron(III) trichloride as an oxidant. A high molecular weight polymer over 270,000 in the weight-average molecular weight was quantitatively obtained in mild conditions. This polymer was then reacted with two and four equimolar trimethylsilylchlorosulfonate in dichloromethane to give the corresponding sulfonic acid-functionalized polymers, whose functionalities were 0.69 and 1.19 per a polymer unit, which were translated to be 1.73 and 2.49 mequiv/g in ion exchange capacity (IEC), respectively. These polymers showed excellent proton conductivity up to 2 × 10⁻¹ S/cm at 80 °C and 95% relative humidity.