Heat stable and organosoluble polyimides containing laterally-attached phenoxy phenylene groups

In this research a diamine monomer containing two phenoxy phenylene lateral groups, 2,2′-bis[(p-phenoxy phenyl)]-4,4′-diaminodiphenyl ether (PPAPE) was used to prepare novel wholly aromatic polyimides by thermal or chemical two-step polycondensation reactions. Comonomers including pyromellitic dianhydride (PMDA), 4,4′-oxydiphthalic anhydride (ODPA), and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) were used for the polyimidization reactions. A reference polyimide was also prepared by the reaction of 4,4′-diaminodiphenyl ether (DADPE) with pyromellitic dianhydride (PMDA). The limited viscosity numbers as well as [`(M)]<sub>n</sub> \overline{M}_n and [`(M)]_w \overline{M}_w values of the resulting polymers were determined. All PPAPE-resulted polyimides had excellent organosolubility in common polar solvents. A low crystallinity extent was only observed using their wide-angle X-ray diffractograms (WAXD). The prepared hinged polyimides could also be cast into transparent and flexible films. The glass transition temperatures of the resulting polyimides were determined by differential scanning calorimetry (DSC) analyses. The thermograms obtained from thermogravimetric analyses (TGA) showed that the phenoxy phenylene lateral groups attached to the macromolecular backbones had no substantial diminishing effect on the thermal stability of these structurally-modified polyimides.     

Synthesis and properties of novel side-chain-type sulfonated polyimides

A series of side-chain-type sulfonated polyimides (SPIs) were synthesized from 4,4′-ketone dinaphthalene-1,1′,8,8′-tetracarboxylic dianhydride (KDNTDA), 2,2′-(4-sulfophenoxy) benzidine, and nonsulfonated diamines. The SPIs showed anisotropic membrane swelling in water with 2–4 times larger swelling in thickness direction than that in plane one, being much different from SPIs derived from 1,4,5,8-naphthalenetetracarboxylic dianhydride. They exhibited good solubility in dimethyl sulfoxide and 1-methyl-2-pyrrolidone even in proton form, which is favorable for processing in fuel cell applications. KDNTDA-based SPIs displayed good mechanical properties with reduced viscosities ranged from 1.1 to 2.4 dl g⁻¹ at 35 °C in triethylamine salt form. They also showed reasonably high proton conductivity and thermal stability.     

Structure–property relationships for partially aliphatic polyimides

The structure–property relationship was studied for partially aliphatic polyimides containing alicyclic dianhydride and aromatic diamine unit. Rel-[1S,5R,6R]-3-oxabicyclo[3,2,1]octane-2,4-dione-6-spiro-3′-(tetrahydrofuran-2′,5′-dione) (DAn) was used as an unsymmetrical spiro dianhydride, and 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA) and bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BOCA) were used as symmetrical non-spiro dianhydrides. The dianhydrides were polymerized with two aromatic diamines, 4,4′-oxydianiline (ODA) and 4,4′-(hexafluoroisopropylidene)dianiline (FDA), using a conventional two-step chemical imidization method. Structures of the PAl-PIs prepared were confirmed by ¹H-NMR and FT-IR spectroscopy. Solubility of the polyimides was tested in various organic solvents. Thermal properties of the PAl-PIs were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). UV-visible spectroscopy was performed to evaluate the optical transparency of the polyimides. The effect of monomer structure on the properties was studied. The PAl-PIs prepared from DAn showed improved solubility, thermal properties, and transparency when compared with PAl-PIs derived from CPDA and BOCA. It is considered that the rigid, unsymmetrical spiro structure of DAn leads to rigidity, bulkiness, irregularity, and non-linearity of the polyimide chains, resulting in the enhanced properties of DAn polyimides. The molecular arrangement in the polyimides has also been studied by wide-angle X-ray diffraction (WAXD) and was correlated with the properties.     

Synthesis,characterization, and gas permeability of aromatic polyimides containing pendant phenoxy group

A diamine containing a pendant phenoxy group, 1-phenoxy-2,4-diaminobenzene, was synthesized and condensed with different aromatic dianhydrides [4,4′-oxydiphthalic dianhydride, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride, 3,3′,4,4′-benzophenone tetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracorboxylic dianhydride, and pyromellitic dianhydride] by one-step synthesis at a high temperature in m-cresol to obtain polyimides in high yields. Most of the polyimides exhibited good solvent solubility and could be readily dissolved in chloroform, sym-tetrachloroethane, N,N-dimethylformamide, N,N-dimethylacetamide, and nitrobenzene. Their inherent viscosities were in the range of 0.33–1.16 dL/g. Wide-angle X-ray spectra revealed that these polymers were amorphous in nature. All these polyimides were thermally stable, having initial decomposition temperatures above 500°C and glass-transition temperatures in the range of 248–281°C. The gas permeability of 4,4′-oxydiphthalic dianhydride and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride based polyimides was investigated with pure gases: He, H₂, O₂, Ar, N₂, CH₄, and CO₂. A polyimide containing a  C(CF₃)₂ linkage showed a good combination of permeability and selectivity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Synthesis and properties of polyimides based on isomeric (4, 4′-methylenediphenoxyl) bis (phthalic anhydride)s (BPFDAs)

Isomeric (4, 4′-methylenediphenoxyl) bis (phthalic anhydride)s (BPFDAs)were synthesized and their structures were determined via IR spectra and ¹H NMR. Polyimides were then prepared from isomeric BPFDAs and aromatic diamines in N, N-Dimethylacetamide (DMAc) via the conventional two-step method. Polyimides based on 3, 3′-BPFDA are soluble in common organic solvents at room temperature, while polyimides based on 4, 4′-BPFDA were only partially soluble in high-boiling-point solvent even upon heating. The 5% weight-loss temperatures (T _5% ) of these polyimides were in the range of 430–500 °C in air. Dynamic mechanical thermal analysis (DMTA) indicated that the glass-transition temperatures of polyimides from 3, 3′-BPFDA are around 10–20 °C higher than those of polyimides from 4, 4′-BPFDA. The wide-angle X-ray diffraction showed that all polyimides are amorphous.     

Ortho alkyl substituents effect on solubility and thermal properties of fluorenyl cardo polyimides

Five fluorenyl cardo diamines containing different alkyl substituents were synthesized and characterized. A series of fluorenyl cardo polyimides were prepared by polycondensation of these cardo diamines with 4,4′-oxydiphthalic anhydride (ODPA), 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,3′,4,4′-biphenyl tetracarboylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA). Most of fluorenyl cardo polyimides exhibited excellent solubility in common organic solvents such as m-cresol, chloroform, tetrahydrofuran (THF), N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide (DMAC) etc. and intrinsic viscosity in N,N-dimethylacetamide (DMAC) ranged from 0.31 to 0.92 dl/g. T_g of polyimides based on ODPA decrease with the number and size of alkyl substituents on fluorenyl cardo diamine. The results show that the incorporation of noncoplanar structure led by the introducing alkyl substituents on fluorenyl cardo diamines improves the solubility of cardo polyimides in organic solvents without sacrificing thermal properties.     

Preparation and Properties of Cyano-Containing Polyimide Films Based on 2,6-Bis(4-aminophenoxy)- benzonitrile

Summary A series of cyano-containing polyimides were synthesized from 2,6-bis(4-amino- phenoxy)benzonitrile and some aromatic dianhydride monomers by solution polycondensation. The poly(amic acid) films could be obtained by solution-cast from N-methyl-2-pyrrolidinone solutions and thermally converted into tough polyimide films. Structure and physical properties of thin films of those polyimides were measured by FTIR, TGA, dynamic mechanical analysis and LCR hitester et al. Results showed that the polyimides prepared from 2,6-bis(4-aminophenoxy)- benzonitrile and 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride or 4,4’-(hexafluoropropylidene)diphthalic anhydride exhibited more excellent energy-damping characteristic and excellent solubility in NMP, DMF, DMAc, DMSO, THF and CHCl₃, whereas the polyimides from 2,6-bis(4-aminophenoxy)benzonitrile and 3,3’,4,4’-biphenyltetracarboxylic dianhydride or Pyromellitic dianhydride were insoluble in polar and nonpolar organic solvents. All polyimides indicated higher glass transition temperatures, excellent thermal stability and tensile properties. Incorporating a nitrile group into the polyimide backbone would enhance the dielectric constant of the polyimide films.     

Synthesis of new diacid monomers and poly(amide-imide)s: study of structure–property relationship and applications

Two diimide-diacid monomers 4,4′-bis[4″-(trimellitimido)phenyl isopropylidene-4″′-phenoxy]diphenyl sulfone and 4,4′-bis[4″-(trimellitimido)phenylisopropylidene-4″′-phenoxy] were synthesized. The structures of the monomers were characterized by FT-IR and ¹H-NMR spectroscopy. A series of novel poly(amide-imide)s were prepared from this two diacids and aromatic diamines through phosphorylation reaction. The PAIs were characterized by FT-IR, ¹H-NMR, XRD, TGA, and DSC, solution viscosity, solubility test and electrical properties. Poly(amide-imide)s showed excellent solubility due to the presence of flexible groups and isopropylidene unit in the polymer backbone. They also exhibited good thermal stability and the temperatures at which 10% weight loss occurred in the range 385–465 °C. These PAIs found to have a dielectric constant in the range 3.25–4.20 at 10 kHz and have excellent electrical insulation character and can be used as insulation materials for electrical items operating at elevated temperatures.     

Synthesis and characterization of soluble polyamides from bis-[(4′-aminobenzyl)-4-benzamide] ether and various diacids

New aromatic diamine containing preformed amide, ether, and methylene; bis-[(4′-aminobenzyl)-4-benzamide] ether (BABE), was synthesized and characterized by FT-IR, NMR, and mass spectrometry. Aromatic–aliphatic polyamides were prepared from BABE with aliphatic/aromatic diacids via Yamazaki’s polymerization. The polyamides were characterized by FT-IR, ¹H NMR, inherent viscosity [η_inh], solubility tests, differential scanning calorimetry [DSC], thermogravimetric analysis [TGA], and X-ray diffraction [XRD]. Polyamides had inherent viscosities 0.35–0.84 dL/g, soluble in aprotic polar solvents like N-methyl-2-pyrrolidone, N, N-dimethyl acetamide and dimethyl sulphoxide containing LiCl due to an amorphous to partially crystalline morphology; as XRD patterns indicated. DSC analysis of polyamides showed glass transition temperatures 166–268 °C. Polyamides showed high thermal stability as they did not degrade below 300 °C, had 10% weight loss temperature higher than 375 °C, and the char yields at 900 °C were 22–55%; indicating potential applications as engineering materials.     

Synthesis and properties of aromatic polyimides based on ether-sulfone-diamines

Two diamine monomers, 4,4′-[sulfonylbis(1,4-phenyleneoxy)]dianiline (III _a ) and 4,4′-[sulfonylbis(2,6-dimethyl-l,4-phenyleneoxy)]dianiline (III _b ), were prepared by an aromatic nucleophilic substitution of 4,4′-sulfonyldiphenol (I _a ) and 4,4′-sulfonylbis(2,6-dimethylphenol) (I _b ) with p-chloronitrobenzene in the presence of potassium carbonate, followed by hydrazine catalytic reduction of the intermediate dinitro compounds. The diamines III _a and III _b were used as monomers with various aromatic tetracarboxylic dianhydrides (IV _a–f ) to synthesize polyimides. The polymerization was conducted in two steps via the formation of a poly(amic acid) precursor followed by thermal cyclodehydration. The poly(amic acid)s had inherent viscosities above 0.87 and up to 2.56 dL/g. Most poly(amic acid)s could be coated and thermodehydrated into flexible and transparent polyimide films. The polyimides derived from the dianhydrides containing-O-and-SO₂-or-C(CF₃)₂-bridging groups between the phthalic anhydride units were soluble in some organic solvents such as N,N-dimethylacetamide (DMAc) and N,N-dimethylformamide (DMF). The glass transition temperatures (T_g) of the polyimides were in the range from 254 to 300 °C. The methyl-substituted polyimides exhibited slightly higher solubility and higher T_g compared to the corresponding unsubstituted polyimides. Thermogravimetric analysis (TG) showed that the polyimides containing methyl substitutents started to lose weight around 450 °C and the unsubstituted ones started to lose weight around 550 °C.     

Effect of chemical structure of aromatic dianhydrides on the thermal, mechanical and electrical properties of their terpolyimides with 4,4′-oxydianiline

Aromatic terpolyimides were synthesized by the reaction of 3,3′,4,4′-oxydiphthalicdianhydride(ODPA), 3,3′,4,4′-biphenyldianhydride(BPDA) and 3,3′,4,4′-benzophenonetetracaboxylicdianhydride(BTDA) with 4,4′-oxydianiline(ODA) via thermal imidization with the view to enhance their tensile properties without compromising thermal properties compared to their homo and copolyimides. Their films were characterized by FTIR, TGA, DSC and XRD. Their FTIR spectra established formation of polyimide by the characteristic vibrations at 1375cm⁻¹(C-N stretch) and 1113 cm⁻¹(imide ring deformation). TGA results showed imidization of residual polyamide acid close to 250 °C and decomposition of polyimides at about 540 °C. XRD results showed amorphous nature for all terpolyimides. Their tensile strength and tensile modulus were higher than either homo or copolyimides. Incorporation of BPDA, without bridging groups between the aromatic rings into the backbone of ODPA/BTDA-ODA is suggested as the cause for such an enhancement. Such terpolyimide can find application as adhesives in making flexible single/multilayer polyimide metal-clad laminates in flexible printed circuits and tape automated bonding applications. In addition, the terpolyimide, BPDA/BTDA/ODPA-ODA (mole ratio 0.5:0.25:0.25:1), showed low dielectric constant (3.52) as BPDA could offer slight rigidity by which the orientation of polar groupings could be reduced.     

Synthesis and properties of polyimides from isomeric bis(dicarboxylphenylthio)diphenyl sulfone dianhydrides

4,4′-Bis(3,4-dicarboxyphenylthio)diphenyl sulfone dianhydride(4,4′-PTPSDA) and 4,4′-bis(2,3-dicarboxyphenylthio)diphenyl sulfone dianhydride(3,3′-PTPSDA) were synthesized from chlorophthalic anhydrides and bis(4-mercaptophenyl)sulfone. Their structures were determined via IR spectra, ¹H NMR and elemental analysis. A series of polyimides were prepared from isomeric PTPSDAs and aromatic diamines in 1-methyl-2-pyrrolidinone (NMP) via the conventional two-step method. Polyimides based on 4,4′-PTPSDA and 3,3′-PTPSDA have good solubility in polar aprotic solvents and phenols. The 5% weight-loss temperatures of isomeric polyimides were near 500 °C in N₂. DMTA and DSC analyses indicated that the glass-transition temperatures of polyimides from 3,3′-PTPSDA are higher than those of polyimides from 4,4′-PTPSDA. The wide-angle X-ray diffraction showed that all polyimides are amorphous. The polyimides from 3,3′-PTPSDA showed higher permeability but lower permselectivity compared with those from 4,4′-PTPSDA.     

Synthesis and properties of novel poly(aryl ether ketone)s containing imide linkages in the main chains

A new monomer containing imide linkages, bis[4-(p-phenoxybenzoyl)-1,2-benzenedioyl]-N,N,N′,N′-4,4′-diaminodiphenyl ether (BPBDADPE), was prepared by the Friedel–Crafts reaction of bis(4-chloroformyl-1,2-benzenedioyl)-N,N,N′,N′-4,4′-diaminodiphenyl ether (BCBDADPE) with diphenyl ether (DPE). Novel poly(aryl ether ketone)s containing imide linkages in the main chains (PEK-I) were synthesized by electrophilic Friedel–Crafts solution copolycondensation of terephthaloyl chloride (TPC) with a mixture of DPE and BPBDADPE. The polymers were characterized by different physico-chemical techniques. The polymers with 10–40 mol% BPBDADPE are semicrystalline and had increased T _gs over commercially available poly(ether ether ketone) (PEEK) and poly(ether ketone ketone) (PEKK) (70/30) due to the incorporation of imide linkages in the main chains. The polymers IV and V with 30–40 mol% BPBDADPE had not only high T _gs of 182–183 °C, but also moderate T _ms of 341–343 °C, having good potential for melt processing and exhibited high thermal stability and good resistance to common organic solvents.     

Preparation of novel polyimides with high thermal stability of dipole alignment for electro-optic applications

3,4-Bis-(3,4-dicarboxyphenylcarboxyethoxy)-1-(2,2-dicyanovinyl)benzene dianhydride (4) was prepared and reacted with 1,4-phenylenediamine and 4,4’-oxydianiline to yield novel Y-type polyimides 5-6 containing 3,4-dioxybenzylidenemalononitrile groups as NLO-chromophores, which constitute parts of the polymer backbones. The resulting polyimides 5-6 were soluble in polar solvents such as acetone and N,N-dimethylformamide. Polymers 5-6 showed a thermal stability up to 330 °C in thermogravimetric analysis thermograms with T _g values obtained from differential scanning calorimetry thermograms in the range of 181–190 °C. The second harmonic generation (SHG) coefficients (d ₃₃) of poled polymer films at the 1064 nm fundamental wavelength were around 4.73×10^-9 esu. The dipole alignment exhibited a thermal stability even at 20 °C higher than the glass-transition temperatures, there was no SHG decay below 200 °C because of the partial main chain character of polymer structure, which was acceptable for nonlinear optical device applications.     

Synthesis and characterization of polyimides based on isopropylidene-containing bis(ether anhydride)s

Two bis(ether anhydride)s, 4,4′-[1,4-phenylenebis(isopropylidene-1,4-phenyleneoxy)]-diphthalic anhydride (IV _a) and 4,4′-[isopropylidenebis(1,4-phenylene)dioxy]diphthalic anhydride (IV _b), were prepared in three steps starting from the nucleophilic nitrodisplacement reaction of 4-nitrophthalonitrile with α,α ′-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene (I _a) and 4,4′-isopropylidenediphenol (I _b) in N,N-dimethylformamide (DMF) in the presence of potassium carbonate. The bis(ether anhydride)s IV _a and IV _b were polymerized with various aromatic diamines to obtain two series of poly(ether amic acid)s VI _a–g and VII _a–g with inherent viscosities in the range of 0.30∼0.74 and 0.29∼1.01 dL/g, respectively. The poly(ether amic acid)s were converted to poly(ether imide)s VIII _a–g and IX _a–g by thermal cyclodehydration. Most of the poly(ether imide)s could afford flexible and tough films, and they showed high solubility in polar solvents such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide, and m-cresol. The obtained poly(ether imide) films had tensile strengths of 45∼83 MPa, elongations-to-break of 6∼27%, and initial modulus of 0.6∼1.7 GPa. The T_gs of poly(ether imide)s VIII _a–g and IX _a–g were in the range of 194∼210 and 204∼243 °C, respectively. Thermogravimetric analysis (TG) showed that 10% weight loss temperatures of all the polymers were above 500 °C in both air and nitrogen atomspheres.     

Synthesis of highly soluble and transparent polyimides

A novel aromatic diamine, 3,3′‐diisopropyl‐4,4′‐diaminophenyl‐4″‐methyltoluene with a 4‐methylphenyl pendant group and isopropyl side groups, was designed and synthesized in this study. Then it was polymerized with various aromatic dianhydrides including pyromellitic dianhydride, 3,3′,4,4′‐biphenyltetracarboxylic dianhydride, 4,4′‐oxydiphthalic anhydride, 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride and 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride via a one‐pot high temperature polycondensation procedure to produce a series of aromatic polyimides. These polyimides exhibited excellent solubility even in common organic solvents, such as chloroform and tetrahydrofuran. The flexible and tough films can be conveniently obtained by solution casting. The films were nearly colorless and exhibited high optical transparency, with the UV cutoff wavelength in the range 302–365 nm and the wavelength of 80% transparency in the range 385–461 nm. Moreover, they showed low dielectric constants (2.73–3.23 at 1 MHz) and low moisture absorption (0.13%–0.46%). Furthermore, they also possessed good thermal and thermo‐oxidative stability with 10% weight loss temperatures (T_10%) in the range 489–507 °C in a nitrogen atmosphere. The glass transition temperatures of all polyimides are in the range 262–308 °C. Copyright © 2012 Society of Chemical Industry     

Synthesis and characterization of nonlinear optical side-chain polyimides containing the thiadiazole chromophores

Thermally stable second-order nonlinear optical (NLO) polyimides were synthesized using a standard condensation polymerization technique. The polyimides were prepared from 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and pyromellitic dianhydride (PMDA) with two aromatic azo- and diazo-diamine derivatives as the NLO chromophores. The resulting polyimides were characterized by FTIR, ¹H-NMR, UV-vis spectroscopies, differential scanning calorimetry, thermogravimetric analysis, and gel permeation chromatography. The weight-average molecular weights of polyimides determined by gel permeation chromatography (GPC) were in the range of 32,100 to 39,300 (M_w/M_n = 1.58–1.74). All the polyimides exhibited an excellent solubility in many of the aprotic polar organic solvents, manifesting that these polyimides offer good processability. The glass transition temperature for the resulting polyimides was in the range of 152 to 194°C and most of them showed high thermal stability. Particularly, the polyimides containing diazo group and PMDA backbone showed an enhanced thermal stability and glass transition temperature. The second harmonic generation (SHG) coefficients (d₃₃) of the poled polyimide films range from 43.71 to 80.49 pm/V at 532 nm. Further, it is noticed that there was no SHG decay below 180°C because of the partial main-chain character of the polyimide structure, which is acceptable for nonlinear optical device applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and properties of new aromatic polyimides based on 2,2′‐dibromo‐4,4′,5,5′‐benzophenone tetracarboxylic dianhydride

New polyimides with enhanced thermal stability and high solubility were synthesized in common organic solvents from a new dianhydride, 2,2′‐dibromo‐4,4′,5,5′‐benzophenone tetracarboxylic dianhydride (DBBTDA). DBBTDA was used as monomer to synthesize polyimides by using various aromatic diamines. The polymers were characterized by IR and NMR spectroscopy and elemental analysis. These polyimides had good inherent viscosities in N‐methyl‐2‐pyrrolidinone (NMP) and also high solubility and excellent thermo‐oxidative stability, with 5 % weight loss in the range 433 to 597 °C. Copyright © 2004 Society of Chemical Industry     

Thermostable foam organoplastics made from polyimide binders and polyimide felt

A series of composite materials of a new type — foam organoplastics — was obtained from foamed polyimide binders reinforced with Arimid T polyimide felt, and commercially available aromatic monomers were used. Use ofDPO (3,3′,4,4′-diphenyloxidetetracarboxyic acid) dianhydride in the H-complex allows obtaining a melt of lower viscosity (300 Pa-sec), and the viscosity almost does not change at 95°C for 20 min. The viscosity of melts of the H-complexes based on BZP (3,3′, 4,4′-benzophenonetetracarboxylic acid) tends to increase rapidly to the level of 10⁵ Pa·sec, probably due to further “crosslinking” of the H-complex in the conditions of the melt. Replacing the carcinogenic 4,4′-diaminodiphenylmethane (DADPM) diamine by commercially available 4,4′-diaminodiphenyl ether (DADPE) does not significantly alter the rheological behavior of the H-complex melt at 95°C and does not decrease the mechanical characteristics of the foam composites. The mechanical characteristics (bending strength, compressive and shear moduli) of the foam composites based on H-complexes with DPO dianhydride are 1.5 times higher than for the same foam composites using BZP dianhydride. The foam composites based on DPO do not undergo brittle failure but simply bend in bending tests, which can be used to obtain new elastic foam materials. The effect ofnanoparticles on the properties of the foam composites was established. It is expedient to use montmorillonite nanoparticles, which increases the modulus of elasticity and rigidity of the material. __________ Translated from Khimicheskie Volokna, No. 5, pp. 66–70, September–October, 2006.     

Synthesis and characterization of poly(arylene ether ketone)s containing triazole units through click chemistry

In order to develop a novel process for poly(arylene ether ketone)s with high thermal and chemical stability, a series of poly(aylene ether ketone)s containing triazloe moieties were synthesized via the click chemistry of 4,4′-bis(azidomethyl) diphenyl ketone (BADPK) and bisethynyl compounds (BEAE1-5). The resulting polymers were characterized by using IR and ¹H NMR techniques. The solubility data showed that samples possessed good solubility in highly polar solvents. Molecular mass of these samples was determined by GPC which indicated they exhibited reasonable molecules weights and relatively small polydispersity. Furthermore, thermal stability of the samples was evaluated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), which indicated that they possessed good thermal stability and high T _g (100–140 °C). All the polymers were amorphous confirmed by DSC and X-ray diffraction (WAXD).