Synthesis, structure and ring-opening polymerization of phenolphthalein macrocyclic polyarylates

Phenolphthalein based polyarylate macrocyclic oligomers were selectively synthesized by an interfacial polycondensation reaction of o-phthaloyl dichloride with phenolphthalein. The high selectivity benefits from the role of phenolphthalein as a color indicator, an efficient phase transfer catalyst, acid a preferred conformation of the starting materials as indicated by analyzing a single-crystal X-ray structure of an analogous macrocycle. The melt ROP of phenolphthalein polyarylate cyclic dimer was studied using nucleophilic initiators, The molecular weight of the resulting polymers builds up very rapidly at the very early stage of polymerization but decreases with time. During the ROP of cyclic dimer, analogous macrocycles with higher degree of polymerization (n greater than or equal to 3) and linear oligomers were produced by backbiting reaction especially at later stage of polymerization. Conversion of cyclic dimer is very fast at the earlier stage of polymerization and then increases slowly with time as analyzed by gel permeation chromatography. However, the total amount of cyclic oligomers in the ROP system increases with time at the later stage of polymerization because of the formation of larger macrocycles. The resulting polymers are amorphous. Glass transition temperatures (T(g)s) of these polymers are influenced by the polymerization time, type of initiator, and initiator concentration.

X-ray crystal structure and molecular mechanics calculations of (2,6-iso-dipropyl-phenylamide) dimethyl (tetra-methylcyclopenta-dienyl) silane titanium dichloride

Crystal and molecular structure of (2.6-dipropylphenylamide) dimethyl (tetra-methyl cyclopentadienyl) silane titanium dichloride (I) was fully characterized by X-ray diffraction. The crystal is obtained from a mixture of ether/hexane as orthorhombic. with a = 12.658 (3) Angstrom. b = 16.62 (3) Angstrom. c = 11.760 (2) Angstrom. V = 2474.2 (9) Angstrom(3). Z = 4, space group Pnma. R = 0.0399; Componud I compose of the pi-bounded ring with its dimethylsilyl-dipropyl phenyl amido group and the two terminal chloride atoms coordinated to central metal to form a so-called constrained geometry catalyst (CGC) structure. The result of molecular mechanics (MM) calculations on compound I shows that bond lengths and bond angles from the MM calculation are comparable to the data obtained from the X-ray diffraction study. The relation of the structure of CGCs and their catalytic activity by MM calculations is also discussed.

Synthesis and crystal structure of a new supermolecular compound: [C12H24O6][H3PMo12O40]center dot 22H(2)O (C12H24O6=18-crown-6)

The title compound, [C12H24O6][H3PMo12O40]. 22H(2)O, was synthesized by the self-assembly of 18-crown-6 (abbreviated as C12H24O6 or 18C6) and H3PMo12O40 in the mixed solvent of CH3OH and CH3CN, and was characterized by IR, H-1 NMR and Xray diffraction for the first time. Crystal data: Triclinic, P (1) over bar, a = 13.428(3) Angstrom, b = 13.557(3)A, c = 14.642(3) Angstrom, a = 105.39(3)degrees, beta = 90.06(3)degrees, gamma = 119.56(5)degrees, V = 2207.5(8) Angstrom(3), Z = 1, R1 = 0.0719, wR2 = 0.1990. It has a disordered alpha-Keggin PMo12O403- anion, which contains the strong alternating short (mean 1.844 Angstrom) and long (mean 1.958 Angstrom) Mo-O-Mo bonds. In the unit cell, crown ethers and molybdophosphates are alternatively arranged in good order along c-axis. An oxonium ion is located at the center of a crown ether molecule., Oxonium ion interacts with 18C6 by the means of hydrogen bonds (mean 2.7771 Angstrom), which are electrostatic or resonant. The observations show the existence of [H3O(C12H24O6)](+) (C) 2000 Elsevier Science B.V. All rights reserved.

Photochemical synthesis and crystal structure of a charge transfer salt [HMDH2][(H2PMoMo11O40)-Mo-v]center dot 2AA center dot 3H(2)O center dot DMF

The title supramolecular compound, [HMDH2][(H2PMoMo11O40)-Mo-V] . 2AA . 3H(2)O . DMF (HMD = hexamethylene diamine; AA=acetaldehyde; DMF=N,N-dimethyl formamide), has been photochemically synthesized by using elemental analysis, IR, solid diffusion reflectance, electronic spectra, ESR spectra and X-ray single-crystal analysis. The crystallographic data: triclinic, P (1) over bar, a=14.092(2), b=14.347(3), c=14.358(3)Angstrom, alpha = 75.10(3), beta = 80.70(3), gamma = 80.73(3)degrees, V = 2746.6(10)Angstrom (3), Z = 2, M-r = 2081.68, D-c=2.517g/cm(3), F(000) =1970, mu (MoK alpha) =2.766mm(-1). The structure has been refined to R =0.0832 and wR=0.2638, by full-matrix least-squares method. The title compound is composed of hexamethylene diamine, two acetaldehyde molecules, three water molecules, one N,N-dimethylformamide and [(H2PMoMo11O40)-Mo-V](2-) heteropoly anion.

Synthesis and properties of aromatic polyimides derived from 2,2,' 3,3 '-biphenyltetracarboxylic dianhydride

2,2,'3,3' -Biphenyltetracarboxylic dianhydride (2,2,'3,3'-BPDA) was prepared by a coupling reaction of dimethyl 3-iodophthalate. The X-ray single-crystal structure determination showed that this dianhydride had a bent and noncopolanar structure, presenting a striking contrast to its isomer, 3,3,'4,4'-BPDA. This dianhydride was reacted with aromatic diamines in a polar aprotic solvent such as N,N-dimethylacetamide (DMAc) to form polyamic acid intermediates, which imidized chemically to polyimides with inherent viscosities of 0.34-0.55 dL/g, depending on the diamine used. The polyimides from 2,2,'3,3'-BPDA exhibited a good solubility and were dissolved in polar aprotic solvents and polychlorocarbons. These polyimides have high glass transition temperatures above 283 degrees C. Thermogravimetric analyses indicated that these polyimides were fairly stable up to 500 degrees C, and the 5% weight loss temperatures were recorded in the range of 534-583 degrees C in nitrogen atmosphere and 537-561 degrees C in air atmosphere. All polyimides were amorphous according to X-ray determination. (C) 1999 John Wiley & Sons, Inc.

Sodium sulfonate-functionalized poly(ether ether ketone)s

A new monomer, sodium 5,5'-carbonylbis(2-fluorobenzenesulfonate) (1), was synthesized by sulfonation of 4,4'-difluorobenzophenone (2) with fuming sulfuric acid. Poly(ether ether ketone)s containing sodium sulfonate groups were synthesized directly via aromatic nucleophilic substitution from the sodium sulfonate-functionalized monomer 1 and Bisphenol A (3) in the presence of potassium carbonate in dimethyl sulfoxide. The polycondensation proceeds without any side reactions. The differential scanning calorimetry measurement indicated that the polymers are amorphous and the glass transition temperatures increase with the content of sodium sulfonate groups in the polymer chain. The degree of substitution with sodium sulfonate groups has strong influence on their thermal stability and solubility.

Synthesis and miscibility studies of rodlike flexible polyimide molecular composites via para-para linked aromatic poly(amic ester) precursors

Para-para linked aromatic poly(amic ester) precursors of rodlike polyimide (PI) BPDA-PDA and polyetherimide (PEI) HQDPA-ODA were synthesized. The para-para linked poly(amic ester)s were employed in this work to obtain, in theory, full-imidized polyimides. The two precursors were mixed by dissolving them in N, N'-dimethyl acetamide and subsequently coagulating in methanol. After thermal imidization, the miscibility behaviour of the resulting composites has been studied by means of dynamic mechanical analysis (d.m.a.) and differential scanning calorimetry (d.s.c.). The composites show a single glass transition temperature (T-g) at both d.m.a. and d.s.c. in which the T-g increases with increasing PI content. These Tg values are reproducible in repeated heating cycles, suggesting the true miscibility of the blends. (C) 1997 Elsevier Science Ltd.

Synthesis, characterization and ionic conductivity of solid polymer electrolytes based on modified alternating maleic anhydride copolymer with oligo(oxyethylene) side chains

Three comb polymers (CP) based on modified alternating methyl vinyl ether/maleic anhydride copolymer with oligo-oxyethylene side chains of the type -O(CH2CH2O)(n)CH3 were synthesized and characterized, and the ionic conductivity of CP/salt complexes is reported. The conductivity of these complexes was about 10(-5)-10(-6) S cm(-1) at room temperature. The conductivity, which displayed non-Arrhenius behaviour, was analysed using the Vogel-Tammann-Fulcher equation. The conductivity maxima appear at lower salt concentration, when CP has longer side chains. Infrared (i.r.) was used to study the cation-polymer interaction. I.r. results also indicate that the ester in CP might decompose at 140 degrees C and reproduce the maleic anhydride ring. (C) 1997 Elsevier Science Ltd.

Synthesis and characterization of polypyrrole-polyurethane cationomer composites

Poly(ether urethane) cationomers based on poly(oxytetramethylene), 4,4'-bibenzyldiisocyanate, N-methyldiethanolamine as chain extender, and acrylic acid/poly(acrylic acid) as quaternization agent were synthesized. Pyrrole (15 wt.-%) was polymerized in films of the ionomer containing CuCl2. The films were characterized by dynamic mechanical analysis, thermogravimetry and differential scanning calorimetry. The electric conductivity of the film without polypyrrole is 7.5 . 10(-12) Omega(-1)cm(-1), while incorporation of polypyrrole increases the conductivity to 4.5 . 10(-6) Omega(-1) cm(-1).

Synthesis and ionic conductivity studies of solid polymer electrolytes based on modified alternating maleic anhydride copolymer with oligo(oxyethylene) side chains

Comb-like polymers (CP) based on modified alternating methyl vinyl ether/maleic anhydride copolymer with oligo-oxyethylene side chains of the type-O(CH2CH2O)(n)CH3 have been synthesized and characterized, and complexed with LiNO3 to form an amorphous polymer electrolyte. CP/salt complexes showed conductivity up to 10(-5) S/cm at room temperature. The temperature dependence of ionic conductivity suggests that the ion transport is controlled by segmental motion of the polymer, shown by linear curves obtained in Vogel-Tammann-Fulcher plots. The ionic conductivity maximum moves to a higher salt concentration as the temperature increases. IR results also indicate that the ester in CP might decompose at 140 degrees C and reproduce the maleic anhydride ring.

Novel polyaryletherketones containing various pendant groups .1. Synthesis and characterization

Novel high glass transition temperature polyaryletherketones, containing pendant amido, alkyl, and carboxyl groups with reduced viscosity above 0.54 dL/g, were synthesized via solution nucleophilic polycondensation reaction of phenolphthalin, 2',2 ''-diisopropyl-5',5 ''-dimethylphenolphthalin, and 3,3'-bis(4-hydroxyphenyl)isobenzopyrrolidone with bis(4-nitrophenyl)ketone in the presence of potassium carbonate. By ion exchange with Na+ and K+, four ionomers were also prepared. A new monomer simultaneously containing carboxyl and algyl substituents was synthesized by reduction reaction of 2',2 ''-diisopropyl-5',5 ''-dimethyl-phenolphthalein. The resulting polymers were soluble in a few polar aprotic solvents; transparent, colorless, and tough films could easily be cast from DMF or DMSO solution. The mechanical properties of the films were excellent; and their tensile strength, elongation at break, and tensile moduli were in the range of 67.1-97.1 MPa, 7.8-165%, and 1.47-2.27 GPa, respectively. The prepared polymers showed fairly good thermal stability and resonably high glass transition temperatures above 210 degrees C. (C) 1997 John Wiley & Sons, Inc.

Synthesis and characterization of interpenetrating polymer networks based on polyacrylate and epoxy

The synthesis and properties of simultaneously interpenetrating networks (SINs) based on poly(polyethylene glycol diacrylate) (PEGDA) and epoxy (diglycidyl ether of bisphenol A, DGEBA) were studied. The effect of compositional variation on the morphology and properties of products was investigated. The swelling coefficient, densities, glass transition behavior, and thermal stability of these interpenetrating networks (IPNs) are discussed. Microphase separation morphological structures were found in all PEGDA/DGEBA IPNs. Decreased swelling ratios compared to the calculated swelling coefficients based on the weight additivity of the components were obtained after the formation of IPNs. Increased density and thermal stability were also obtained in these IPNs, implying the existence of interpenetration (topological entanglements) among the component networks.

Miscibility and phase behavior in blends containing random copolymers of poly(ether ether ketone) and phenolphthalein poly(ether ether ketone)

The miscibility and phase behavior of polysulfone (PSF) and poly(hydroxyether of bisphenol A) (phenoxy) with a series of copoly(ether ether ketone) (COPEEK), a random copolymer of poly(ether ether ketone) (PEEK), and phenolphthalein poly(ether ether ketone) (PEK-C) was studied using differential scanning calorimetry. A COPEEK copolymer containing 6 mol % ether ether ketone (EEK) repeat units is miscible with PSF, whereas copolymers containing 12 mol % EEK and more are not. COPEEK copolymers containing 6 and 12 mol % EEK are completely miscible with phenoxy, but those containing 24 mol % EEK and more are immiscible with phenoxy. Moreover, a copolymer containing 17 mol % EEK is partially miscible with phenoxy; the blends show two transitions in the midcomposition region and single transitions at either extreme. Two T(g)s were observed for the 50/50 blend of phenoxy with the copolymer containing 17 mol % EEK, whereas a single composition-dependent T-g appeared for all the other compositions. An FTIR study revealed that there exist hydrogen-bonding interactions between phenoxy and the copolymers. The strengths of the hydrogen-bonding interactions in the blends of the COPEEK copolymers containing 6 and 12 mol % EEK are the same as that in the phenoxy/PEK-C blend. However, for the blends of copolymers containing 17, 24, and 28 mol % EEK, the hydrogen-bonding interactions become increasingly unfavorable and the self-association of the hydroxyl groups of phenoxy is preferable as the content of EEK units in the copolymer increases. The observed miscibility was interpreted qualitatively in terms of the mean-field approach. (C) 1996 John Wiley & Sons, Inc.

SYNTHESIS AND CRYSTAL-STRUCTURES OF A NEW NONCYCLIC LIGAND AND ITS LANTHANIUM(III) COMPLEX

A new non-cyclic ligand, tris(4-carboxy-3-oxabutyl) amine (H3L . HCl) and its lanthanum(III) complex have been prepared and their crystal structures determined. In the lanthanum(III) complex the metal ion is coordinated to one nitrogen atom, three ether o

EXCIMER FLUORESCENCE STUDY ON THE MISCIBILITY OF POLY(VINYL METHYL-ETHER) AND STYRENE-BUTADIENE STYRENE TRIBLOCK COPOLYMER

The excimer fluorescence of a triblock copolymer, styrene-butadiene-styrene (SBS) containing 48 wt% polystyrene was used to investigate its miscibility with poly(vinyl methyl ether) (PVME). The excimer-to-monomer emission intensity ratio I(M)/I(E) can be used as a sensitive probe to determine the miscibility level in SBS/PVME blends: I(M)/I(E) is a function of PVME concentration, and reaches a maximum when the blend contains 60% PVME. The cloud point curve determined by light scattering shows a pseudo upper critical solution temperature diagram, which can be attributed to the effect of PB segments in SBS. The thermally induced phase separation of SBS/PVME blends can be observed by measuring I(M)/I(E), and the phase dissolution process was followed by measuring I(M)/I(E) at different times.