Preparation and properties of novel poly(urethane-imide)s

A series of poly(urethane-imide)s were prepared by a novel approach. Polyurethane (PU) prepolymer was prepared by the reaction of polyester polyol and 2,4-tolylenediisocyanate (2,4-TDI), and then end-capped with phenol. The PU prepolymer was blended with poly(amide acid) or oligo(amide acid) prepared from 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and oxydianiline (ODA) at room temperature in various weight ratios. The blend films obtained by casting and then drying were not transparent, suggesting that phase separation occurred between the polyimide (PI) and PU components. The films became transparent, however, after thermal treatment at 100°C and then 200°C for 1 h each, irrespective of the ratio of the two components. The poly(urethane-imide) films showed good solvent-resistance. Dynamic mechanical analysis of the films showed that glass transition temperatures (T_g) shifted depending on the ratio of PI and PU components. This shift of T_g, along with the transparency of the films, suggests that the PU and PI components employed here are miscible to some extent and that domains of each phase by microphase separation are small. Tensile measurement of the blend films from poly(amide acid) showed that the films are plastic or elastic, depending on the ratio of the components. Thermal stability of the PU was found to increase by the incorporation of polyimide component.     

Adsorption properties of carbon prepared from poly(tetrafluoroethylene)

The adsorption equilibria of benzene were studied on carbon samples prepared by the electrochemical reduction of poly(tetrafluoroethylene) between 10 and 80°C. Adsorption isotherms and isosteric heats of adsorption of benzene were compared with the data obtained for standard activated carbon and for graphitized carbon black. The modified Freundlich equation was used to express adsorption isotherms of benzene on the studied samples. The parameters of the equation gave information on the structure of the samples. This information is consistent with the results of the radial distribution of the electron density and wide-angle X-ray scattering carried out earlier.     

Synthesis and properties of novel fluorinated poly(arylene ether)s

Dibromomethylene‐containing monomer with a tetrafluorobenzene central unit was synthesized using 2,3,5,6‐tetrafluoro‐1,4‐bis(4‐methylphenoxy)benzene as a starting material. This approach enabled preparation of several fluorinated poly(arylene ether)s containing isomeric fragments, with or without allyl or acetyl side groups, which were prepared by interaction of the synthesized tetrafluorobenzene‐based monomer with various types of hydroxyl‐substituted diphenyl ethers. The structure of the synthesized compounds was determined using Fourier transform infrared, ¹H NMR and ¹⁹ F NMR spectroscopy techniques. Most of the resulting polyethers were soluble in chlorinated, ether‐type or polar amide solvents. The molecular weight, mechanical and thermal properties of the synthesized fluorinated poly(arylene ether)s were studied depending on the inherent isomery of macromolecular chains and the nature of functional groups. Some ways of functionalization of the prepared fluorinated polyethers with epoxy and triethoxysilyl groups were proposed. © 2015 Society of Chemical Industry     

Synthesis and properties of novel organosoluble and light-colored poly(ester-amide)s and poly(ester-imide)s with triptycene moiety

Two series of new triptycene-containing poly(ester-amide)s and poly(ester-imide)s were prepared from 1,4-bis(3-aminobenzoyloxy)triptycene with various aromatic dicarboxylic acids and dianhydrides, respectively. The synthesis of the poly(ester-amide)s was achieved by the phosphorylation polyamidation reaction by means of triphenyl phosphite and pyridine, and the synthesis of the poly(ester-imide)s included ring-opening polyaddition to give poly(amic acid)s followed by thermal imidization and chemical imidization to polyimides. All the poly(ester-amide)s and most of the poly(ester-imide)s presented good solubility in many organic solvents and could be solution-cast into transparent and flexible films. These poly(ester-amide)s and poly(ester-imide)s displayed discernible glass-transition temperatures (T_gs) between 242 and 298 °C in the DSC traces and showed moderate thermal stability with 10 wt% loss temperatures above 464 °C in nitrogen or air. These highly optically transparent polymer films possess an ultraviolet-visible absorption cut-off wavelength (λ₀) down to 344 nm. 1,4-Bis(4-aminobenzoyloxy)triptycene was also synthesized and used for polymer synthesis; however, less favorable results were obtained.     

Synthesis and properties of novel poly(coumarin‐amide)s

A novel monomer diacid, 6,6′‐methylenebis(2‐oxo‐2H‐chromene‐3‐carboxylic acid), was synthesized and used in a direct polycondensation reaction with various aromatic diamines in N‐methyl‐2‐pyrrolidone solution containing dissolved LiCl and CaCl₂, using triphenyl phosphite and pyridine as condensing agents to give a series of novel heteroaromatic polyamides containing photosensitive coumarin groups in the main chain. Polyamide properties were investigated by DSC, TGA, GPC, wide‐angle X‐ray scattering, viscosity, and solubility measurements. The copolymers were soluble in aprotic polar solvents, and their inherent viscosities varied between 0.49 and 0.78 dL g^?1. The weight‐average and number‐average molecular weights, measured by gel permeation chromatography, were 27,500–43,900 g mol^?1 and 46,500–66,300 g mol^?1, respectively, and polydispersities in the range of 1.48–1.69. The aromatic polyamides showed glass‐transition temperatures (T_g) ranging from 283 to 329°C and good thermal properties evidenced by no significant weight loss up to 380°C and 10% weight loss recorded above 425°C in air. All the polyamides exhibited an amorphous nature as evidenced by wide‐angle X‐ray diffraction and demonstrated a film forming capability. Water uptake values up to 3.35% were observed at 65% relative humidity. These polymers exhibited strong UV‐vis absorption maxima at 357–369 nm in DMSO solution, and no discernible photoluminescence maxima were detected by exciting with 365 nm. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and properties of novel poly(benzimidazopyrrolone amide)s containing pyridine moieties

A series of new poly(benzimidazopyrrolone amide) (PPA) copolymers were synthesized by a two‐step procedure, which was the solution polycondensation of a novel pyridine‐containing tetraamine with various aromatic dianhydrides at a room temperature and cyclization of the resulting prepolymers at a high temperature, respectively. The resulting prepolymers from the solution polycondensation, that is, poly(amide amino acid)s (PAAAs), had inherent viscosities of 0.82–0.91 dL/g; then, tough and flexible PPA films could be successfully prepared by the casting of the PAAA solutions onto a glass substrate followed by thermal curing with a program temperature procedure up to 350°C. The obtained PPA films exhibited not only excellent thermal properties with onset decomposition temperatures in the range 502–521°C, glass‐transition temperatures in the range 299–337°C, and residual weight retentions at 700°C in air of 29.1–34.8% but also good mechanical properties with tensile strengths of 102.1–115.9 MPa and elongations at break of 6.8–7.4%. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis,characterization, and properties of novel poly(ether urea)s

Two diamines, 2,6‐bis(4‐aminophenoxy)pyridine and 2,6‐bis(5‐amino‐1‐naphenoxy)pyridine, were prepared through the nucleophilic aromatic substitution reaction of 4‐aminophenol and 5‐amino‐1‐naphthol, respectively, with 2,6‐dichloropyridine. Poly(ether urea)s were synthesized through the polyaddition reactions of these diamines with aromatic, semiaromatic, and cycloaliphatic diisocyanates. All the monomers and polymers were fully characterized, and physical properties of the polymers, including the thermal behavior, thermal stability, solubility, and solution viscosity, were studied. The polyureas showed improved thermal stability. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 961–965, 2004     

Synthesis and properties of novel sulfonated poly(phenylquinoxaline)s as proton exchange membranes

Two series of sulfonated poly(phenylquinoxaline)s (SPPQ-x and SPPQ(O)-x, x refers to molar percentage of sulfonated tetraamine monomer) were first synthesized from a sulfonated tetraamine (4,4′-bis(3,4-diaminophenoxy)biphenyl-3.3′-disulfonic acid) and two aromatic bisbenzils (4-phenylglyoxalylbenzil and p,p′-oxydibenzil) in a mild condition. The structures of SPPQ-x and SPPQ(O)-x were characterized by IR and ¹H NMR spectra. The properties of these polymer films, such as water uptake, water swelling ratio, proton conductivity, thermal properties, methanol permeability, hydrolytic and oxidative stability were also investigated. The resulting polymers generally showed good solubility in DMAc and DMSO. Flexible and tough membranes with high mechanical strength were prepared. They show very high thermal, thermooxidative, hydrolytic stabilities and low methanol permeability. SPPQ-100 with the IEC value (2.41 mmol/g) displays the conductivity of 0.1 S/cm and a swelling ratio of 7.3% at 100 °C. The low swelling was attributed to the high rigid of polymer backbones and the strong intermolecular interaction between the basic nitrogen atoms of quinoxaline units and sulfonic acid groups. Moreover, we found that the conductivities of SPPQ(O)-x membranes were higher than SPPQ-x membranes at the similar IEC value. The highest conductivity of 0.2 S/cm was obtained for SPPQ(O)-100 at 140 °C. A combination of excellent dimensional and hydrolytic stabilities indicated that the SPPQ ionomers were good candidate materials for proton exchange membrane in fuel cell applications.     

Synthesis and characterization of novel poly(amide-ether)s bearing imidazole pendants: study of physical and optical properties

Two new para-linked diether-diamines, bis(4-(4-amino-2-(4,5-diphenyl-1H-imidazol-2-yl)phenoxy) phenyl)methanone and bis(4-(4-amino-2-(4,5-diphenyl-1H-imidazol-2-yl)phenoxy) phenyl)hexafluoropropane, bearing two ortho-linked phenyl-substituted imidazole pendants and trifluoromethyl groups were synthesized by the nucleophilic chlorodisplacement reaction of the synthesized 2-(2-chloro-5-nitrophenyl)-4,5-diphenyl-1H-imidazole with 4,4′-dihydroxybenzophenone or 4,4′-(hexafluoroisopropylidene)diphenol in refluxing DMAc in the presence of potassium carbonate. These diamines were utilized to prepare a series of novel poly(amide-ether)s (PAEs) via direct phosphorylation polycondensation with aliphatic and aromatic dicarboxylic acids. The polymeric samples were readily soluble in a variety of organic solvents and formed low-colored and flexible thin films via solution casting. These polymers showed glass-transition temperatures (T _gs) between 204 and 308 °C. Thermal behaviors of the PAEs were characterized by thermogravimetric analysis, and the 10 % weight loss temperatures were found to be in the range of 330–450 °C in N₂. The PAEs exhibited fluorescence emission in solution and in solid state with maxima around 423–494 nm and with the quantum yields in the range of 6–28 %.     

New organosoluble and thermally stable poly(urea-imide)s prepared from one-pot polyaddition reactions

A new class of aromatic poly(urea-imide)s having biphenylene pendant group was prepared by the diphenyl azidophosphate (DPAP) activated one-pot polyaddition reaction of a preformed imide ring-containing dicarboxylic acid, 4-p-biphenyl-2,6-bis(4-trimellitimidophenyl)pyridine ( 1 ) with various aromatic diamines. A model compound was also synthesized by the reaction of diimide-dicarboxylic acid 1 with two mole equivalents of aniline. In this direct method the polymers were prepared by polyaddition reactions of the in situ-formed diisocyanate with the aromatic diamines. The inherent viscosities of the polymers were measured in the range of 0.11–0.15 dL g⁻¹. The ultraviolet λ_max values of the poly(urea-imide)s were also determined. Furthermore, crystallinity of the resultant polymers was evaluated by wide-angle X-ray diffraction method, and they exhibited nearly a noncrystalline nature. All of the resulting polymers exhibited excellent solubility in common polar solvents. The glass transition temperatures of the polymers determined by DSC thermograms were in the range 241–272°C. The temperatures at 10% weight loss from their TGA curves were found to be in the range 406–437°C in nitrogen. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Physicochemical properties of electrochemically prepared poly(pyrrole hexafluorophosphate)

Poly(pyrrole hexafluorophosphate) (PPPF₆) was prepared with the potentiostatic method to supply a constant potential of 1.21 V for 5 h in water/acetonitrile (1/99 vol %) solution of 0.2M pyrrole containing 0.1M tetraethylammonium hexafluorophosphate as a supporting electrolyte. The result of elemental analysis and Fourier transform infrared spectrum showed that it was a PPPF₆ that was doped with ∼28 wt % 6 was irreversible. Scanning electron microscopy was performed to know the morphology of PPPF₆. The result of the differential scanning calorimetry did not show any special peak in temperature range of 25–800°C. From the temperature dependence of the electrical conductivity and electron spin resonance measurement, it was suggested that a possible conduction mechanism for the PPPF₆ polymer should be a small polaron hopping conduction. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 605–612, 1998     

Synthesis and swelling properties of crosslinked poly(orthosilicate)s from cyclohexanedimethanols

Condensations of cyclohexanedimethanol derivatives with tetraethyl orthosilicate in the proper stoichiometric ratio produce crosslinked poly(orthosilicate)s. Synthesized crosslinked polymers have swelling abilities in common organic solvents such as tetrahydrofuran (THF), dichloromethane, benzene and acetone. All these polymers are moderately thermally stable and possess solvent uptake abilities that are not only good and fast but are also regenerable. FTIR, solid‐state ¹³C, ²⁹Si‐NMR and thermal methods were used to characterize these synthesized polymers. The effects of different cyclohexanedimethanol derivatives on the properties of polymers were also examined. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122:1182–1189, 2011     

Conformational properties of poly(alkene sulphone)s in solution: 2. A rotational isomeric state study of the poly(cyclohexene sulphone) chain

The rotational isomeric states model, coupled with the Flory matrix method, was applied to the calculation of the unperturbed mean-square end-to-end distance in poly(cyclohexene sulphone) as a function of several parameters. The calculations were performed for atactic, isotactic and syndiotactic chains; the tacticity arises from the two possible ways, D and L, in which the rings can be attached to the main chain, assuming that the CC bonds are all in the t conformation, as indicated by dielectric measurements. One of the three conformations about each CS bond is strongly hindered and was given zero statistical weight whereas the other two were assigned weights determined by second-order effects, operating over three or more consecutive bonds, and dependent on the chirality of the rings and the coulombic interactions between adjacent dipoles.The calculations for the atactic model, in which a Monte Carlo procedure was used to generate the chain, were found to agree with experiment only if the parameter α was given a value of 5 or greater. This parameter is determined by the relative orientation of successive sulphone dipoles and was expected to have a value less than unity. It appears that specific solvation effects help to stabilize (t, g) and (g, t) CSC bond pairs relative to t, t. Other parameters are not so important.The calculations for the isotactic and syndiotactic models show interesting features, particularly for certain limiting conditions when cyclic or helical structures are generated. For these models there is a greater sensitivity to the various parameters than in the atactic case.     

Comparative study of photoelectric properties of regiosymmetrical poly(3,4-dialkoxythiophene)s

A series of regiosymmetrical poly(3,4-dialkoxythiophene)s: poly(3,4-diamyloxythiophene), poly(3,4-dioctyloxythiophene), poly(3,4-di(2-ethyl-1-hexyloxy)thiophene), and poly(3,4-didodecyloxythiophene) were synthesized by the FeCl₃-oxidative approach. All these polymers were evaluated with NMR, FT-IR, gel permeation chromatography (GPC), thermo-gravimetric analysis (TGA), UV–Vis spectroscopy, and photoluminescence (PL). The polymers have excellent solubility in common organic solvents, and TGA studies show that the polymers lost 5% of their weights on heating to 250 °C above. Investigations of the UV–Vis spectroscopy show that the absorption maxima of the polymer thin films are similar to those in solutions, and the optical band gaps of the polymer thin films are ranging from 2.27 to 2.69 eV. In PL spectra, maxima emission peaks of the polymer thin films lie at 527 to 589 nm, embodying colors from green to yellow, and the quantum yields of the polymers are in the range of 22–28%. All the data indicate that the polymers have good solubility, outstanding thermal stabilities, low band gaps, and high PL quantum yields, and they might be excellent polymeric materials for applications in organic light-emitting diodes (OLEDs), light-emitting electrochemical cells, polymer solar cells, and so on.     

Characterization of novel biodegradable copolyesters prepared from glycolyzed products of poly(ethylene terephthalate)

Poly(ethylene terephthalate), PET reacted with various glycols in the presence of titanium tetraisopropoxide as a catalyst. The glycolyzed PET was fractionated into two parts—soluble and insoluble in CHCl₃—characterized and used as a raw material to synthesize copolyesters. The soluble part in the CHCl₃ part was a mixture of monomers and oligomers, and no melting points were observed. On the other hand, in the insoluble part a melting point was determined. The glycolyzed PET and copoly(succinic anhydride/ethylene oxide), PES were condensed to produce copolymers. The synthesized copolyesters were amorphous and hydrolyzed enzymatically due to a decrease in the crystallinity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1838–1847, 2002; DOI 10.1002/app.10462     

A novel synthetic route to highly cross-linked poly(alkylvinylether)s

Summary p-(2-Vinyloxyethoxy)benzylidenemalononitrile (3) and methyl p-(2-vinyloxyethoxy)benzylidenecyanoacetate (4) was prepared by the condensation of p-(2-vinyloxyethoxy)benzaldehyde with malononitrile or methyl cyanoacetate, respectively. Vinyl ether monomers 3 and 4 polymerized quantitatively with radical initiators in -butyrolactone solution at 65°C. The trisubstituted terminal double bond participated in the vinyl polymerization and radical polymerization of 3 and 4 led to swelling polymers 5 and 6 that were not soluble in common solvents due to cross-linking. Under the same polymerization conditions ethyl vinyl ether polymerized well with model compounds of p-methoxybenzylidenemalononitrile and methyl p-methoxybenzylidenecyanoacetate, respectively, to give 1:1 alternating copolymers 9 and 10 in high yields. Alternating copolymers 9 and 10 were soluble in common solvents such as acetone and DMSO, and the inherent viscosities of the polymers were in the range of 0.36–0.74 dL/g. Films cast from acetone solution were cloudy and tough and T_g values obtained from DSC thermograms were in the range of 59–60°C.     

Synthesis and characterization of novel poly(amide imide)s

Novel poly(amide imide)s having inherent viscosities in the range 0.89–1.56 dL/g were prepared by the method of low temperature polycondensation in solution of N,N-dimethylacetamide (DMA) from aromatic diamines and a new monomer: N-[4″-(chloroformylphenyl)-4′-iminobenzoyl]trimellitimide chloride. The polymers were soluble in polar aprotic solvents and essentially amorphous. They showed glass transition temperatures in the range 310–350°C and decomposition temperatures of 450–460°C. Polymer films, fabricated by casting polymer solutions in DMA, showed tensile strengths in the range 70–90 MPa and moduli values between 3000–4000 MPa. © 1996 John Wiley & Sons, Inc.     

Synthesis and characterization of novel benzhydrol-containing poly(amide-imide)s

A series of novel benzhydrol-containing poly(amide-imide)s (PAIs) have been prepared from a new diimide-dicarboxylic acid, N,N′-bis(4-hydroxycarbonyl)-benzhydrol-3,3′,4,4′-tetracarboxydiimide (BHTDA-DIA), with various diamines by direct polycondensation using triphenyl phosphite and pyridine as condensing agents. The polymers obtained had inherent viscosities of 0.35–0.96 dl g⁻¹. All these PAIs, except polymer PAI-2, were soluble in N-methyl-2-pyrrolidinone and N,N-dimethylacetamide containing LiCl (1 wt%). Tough and flexible PAI films could be obtained by casting PAIs from their DMAc or NMP solutions, except for polymer PAI-2. The polymer films had a tensile strength of 93–111 MPa, an elongation at break range of 4–6%, and an initial modulus range of 2.7–3.8 GPa. The glass transition temperatures of most polymers were found to be above 255 °C. These polymers were fairly stable up to a temperature around or above 400 °C, and lost 10% weight in the range 426–507 °C in nitrogen and 423–515 °C in air. © 1999 Society of Chemical Industry     

Poly(amidine)s and poly(guanidine)s — synthesis and some properties

Synopsis Several poly(amidine) and poly(guanidine) copolymers and their hydrochloride salts were synthesized by introducing the functional groups into suitable polymers. The properties of the resulting copolymers were investigated by base and acid titration.     

Synthesis and properties of novel poly(tetramethylsilnaphthylenesiloxane) derivatives

Novel poly(tetramethylsilnaphthylenesiloxane) derivatives were synthesized and characterized by differential scanning calorimetry (DSC), thermogravimetry (TG), and X-ray diffraction analyses. Poly(tetramethylsilnaphthylenesiloxane) derivatives were obtained by condensation polymerization of the corresponding disilanol derivatives, i.e. 1,4-, 1,5-, 2,6-, and 2,7-bis(dimethylhydroxysilyl)naphthalenes, which were prepared by the Grignard reaction using chlorodimethylsilane and the corresponding dibromonaphthalene derivatives followed by the hydrolyses, catalyzed by palladium on charcoal. The obtained poly(tetramethyl-1,5-silnaphthylenesiloxane) was insoluble in common organic solvents; however, the other polymers exhibited the good solubility in common organic solvents, such as tetrahydrofuran (THF), chloroform, dichloromethane, and toluene. The introduction of tetramethyl-1,5-silnaphthylenesiloxane units into the resulting polymer was confirmed by ¹H NMR spectrum of the copolymer obtained by condensation copolymerization of 1,5-bis(dimethylhydroxysilyl)naphthalene with 1,4-bis(dimethylhydroxysilyl)naphthalene. It was revealed from the DSC and X-ray diffraction measurements that poly(tetramethyl-1,5-silnaphthylenesiloxane) and poly(tetramethyl-2,6-silnaphthylenesiloxane) exhibited the crystallinity; however, poly(tetramethyl-1,4-silnaphthylenesiloxane) and poly(tetramethyl-2,7-silnaphthylenesiloxane) were amorphous. The glass transition temperature (T_g) and the temperature at 5% weight loss (T_d5) of poly(tetramethylsilnaphthylenesiloxane) derivatives with dimethylsilyl group at 1-position of the naphthylene moiety were higher than those at 2-position of the naphthylene moiety. The T_g and melting point (T_m) of the present polymers were higher than those of poly(tetramethyl-1,4-silphenylenesiloxane).