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  • 1995-1999  (11)
  • Polymer and Materials Science  (11)
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  • Polymer and Materials Science  (11)
  • Chemistry  (11)
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 230 (1995), S. 171-178 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Hitzebeständige Poly(vinylalkohol)-Polarisationsfilter mit einer Schicht eines Iod-Komplexes wurden hergestellt, indem im Film enthaltene Metalliodide oxidiert wurden. Filme mit hoher Polarisationsfähigkeit wurden durch Oxidation und anschließendes Strecken erhalten. Die Ergebnisse zeigen, daß (i) die Polarisationsfähigkeit eines PVA-Films hoch ist, der durch Oxidation bei 0°C für 120 s in einer 10 Gew.-proz. wässrigen H2O2-Lösung eines PVA-Films entstanden ist, der 1 mmol oder mehr Kaliumiodid (KI)/g PVA enthält und um 400% verstreckt wurde, (ii) die Hitzebeständigkeit dieses Polarisationsfilters höher ist als diejenige eines aus einem handelsüblichen PVA-Film hergestellten Filters.
    Notes: The polarization properties of iodine complex layer deposited by oxidation of poly(vinyl alcohol) (PVA) containing metal iodide were investigated. Heat-resistant polarizing films with high polarization efficiency were produced by oxidizing and stretching the PVA containing metal iodide. The results indicate that i) the polarization efficiency of a polarizing film prepared by oxidation of a PVA film containing 1 mmol or more of potassium iodide (KI)/g PVA at 0°C for 120 s in a 10 wt.-% aqueous solution of H2O2 and a degree of stretching of 400% is high, ii) the heat resistance of the polarizing film in this experiment is higher than that of a filter prepared from a commercial PVA film.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Poly(etheretherketon) (PEEK)/Poly(phenolphthaleinethersulfon) (PPES)-Blockcopolymere mit PPES-Anteilen zwischen 12 und 44% wurden durch Kondensation von fluorterminierten PEEK-Oligomeren und hydroxyterminierten PPES-Oligomeren hergestellt. Die Abhängigkeit der Copolymereigenschaften von der Zusammensetzung wurde untersucht. Die Copolymeren erwiesen sich als homogen, die Komponenten zeigten gute Verträglichkeit ohne Mikrophasenseparation. Die Copolymeren kristallisierten wie PEEK mit rhombischer Struktur. Der Kristallisationsgrad der Copolymeren was gering und nahm mit steigendem PPES-Gehalt rasch ab. Im Ver-gleich zur Kristallstruktur von PEEK wurden für die Längen der a- und b-Achsen des Copolymer-Kristallgitters - und somit auch für das Zellvolumen - größere Werte gefunden. Die Analyse der isothermen Kristallisationskinetik der Copolymeren ergab für den Avrami-Exponenten einen Wert von 2,0. Mit steigendem PPES-Gehalt der Copolymeren erhöhten sich die Glasübergangstemperaturen stark, die thermische Stabilität nahm jedoch ab. Die PEEK/PPES-Blockcopolymeren ziegten gute mechanische Eigenschaften wie hohe Zugfestigkeiten und Elastizitätsmoduli.
    Notes: Poly(ether ether ketone) (PEEK)/poly(phenolphthalein ether sulfone) (PPES) block copolymers were synthesized by a condensation reaction of fluorine-terminated PEEK oligomers and hydroxy-terminated PPES oligomers. The content of PPES in the copolymers was varied from 12 to 44 wt.-%, and the effect of the compositional variation on the properties was investigated. Microphase separation was not observed and the copolymers formed a homogeneous system having good compatibility. The crystal structure of the copolymers is rhombic, equal to PEEK. The degree of crystallinity of the copolymers was low and decreased rapidly with the increase of PPES content. Concerning the cell parameters of the crystalline unit, a- and b-axes are apparently longer and V is, thus, also larger compared with PEEK. Analyses of the isothermal crystallization kinetics of the copolymers provided an Avrami exponent (n) of 2.0. The glass transition temperature (Tg) of the copolymers greatly rose but the thermal stability became much poorer with the increase of PPES content. PEEK/PPES block copolymers possess good mechanical properties such as high strength and modulus.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 253 (1997), S. 183-191 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Metallisierung von Filmen aus Polyvinylidenfluorid (PVdF) durch Reduzieren eingelagerter Metallchloride und -perchlorate mit wässeriger NaBH4-Lösung wurde untersucht. Die Leitfähigkeit der abgeschiedenen Metallschichten nahm bezüglich des Kations und des Anions in der Reihenfolge Cu2+ 〉 Ni2+ 〉 Co2+ 〉 Fe3+ bzw. Cl- 〉 ClO-4 ab. Die hohe Leitfähigkeit der mit CuCl2 erhaltenen Schicht wird damit erklärt, daß bei der Reduktion, im Gegensatz zur Bildung von Metallboriden bei CoCl2 und NiCl2 und Oxidation bei FeCl3, keine Nebenreaktionen ablaufen und die Oberfäche der Cu-Schicht sehr eben ist.
    Notes: The metallization of poly(vinylidene fluoride) (PVdF) films by reduction of polymer-incorporated metal chlorides and perchlorates with an aqueous NaBH4 solution was investigated. The conductivity of the metal layers deposited by reduction decreased in the order Cu2+ 〉 Ni2+ 〉 Co2+ 〉 Fe3+ regarding the metal cation, and in the order of Cl- 〉 ClO-4 regarding the counter anion. The high conductivity of the Cu layer deposited from PVdF containing CuCl2 is thought to be attributed to the facts that no side-reaction occurs during the reduction in contrast to the formation of metal boride in CoCl2 and NiCl2 systems and iron oxides in FeCl3 system, and the surface of the Cu layer is smooth as compared with that obtained with the Cu(ClO4)2 system.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Poly(etheretherketon) (PEEK)/4,4′-Dihydroxydiphenylsulfon (DHDPS)-Multiblock-Copolymere mit Diphenyloxysulfon(DPOS)-Gehalten zwischen 4,9 und 36,6 Gew.-% wurden aus DHDPS und fluorterminierten PEEK-Oligomeren hergestellt. Das zahlenmittlere Molekulargewicht (Mn) der PEEK-Oligomeren variierte zwischen 470 und 4900. Der Einfluß der Zusammensetzung auf die Eigenschaften der Copolymeren wurde untersucht. Es wurde keine Mikrophasenseparation beobachtet. Die Copolymeren bildeten ein homogenes System mit guter Phasenverträglichkeit. Bei den Copolymeren mit höchstens 23,1 Gew.-% DPOS wurde eine kristalline Struktur beobachtet. Röntgenweit- und Kleinwinkelstreumessungen ergaben eine rhombische Kristallstruktur, wie sie auch bei PEEK gefunden wird. Die Verteilung der Schichtdicken der kristallinen und amorphen Regionen ist relativbreit. Mit Zunahme des DPOS-Gehalts (oder der Abnahme des zahlenmittleren Molekulargewichts der PEEK-Segmente) nahmen der Kristallinitatsgrad und der Schmelzpunkt der Copolymeren ab, und die Glastemperatur (Tg) nahm schrittweisezu.
    Notes: Poly(ether ether ketone) (PEEK)/4,4′-dihydroxydiphenyl sulfone (DHDPS) multiblock copolymers with a content of the diphenoxysulfone (DPOS) moiety between 4.9 and 36.6wt.-% were synthesized by the reaction of DHDPS and fluorine-terminated PEEK oligomers. The number-average molecular weight of PEEK oligomers (Mn) was varied from 470 to 4900. The effect of the compositional variation on the properties was investigated. Microphase separation was not observed. The copolymers formed a homogeneous system having good compatibility. The copolymers whose DPOS contents are not exceeding 23.1 wt.-% (Mn of PEEK segment ≥ 865) have crystalline structure.From the measurements of wide- and small-angle X-ray scatterings it was revealed that the crystal structure of the copolymers is rhombic, equal to PEEK, and the distribution of the thickness of the crystalline and amorphous regions is very broad. The degree of crystallinity and the melting point of the copolymers decreased and the glass transition temperature (Tg) gradually rose with the increase of the DPOS content (or the decrease of Mn of the PEEK segment).
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Macromolecular Rapid Communications 18 (1997), S. 99-105 
    ISSN: 1022-1336
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Five kinds of poly(aryl ether ketone)s (PAEKs) having para-substituted linear molecular chains were synthesized via nucleophilic substitution reaction of the corresponding difluoro- and dihydroxy-compounds. The glass transition temperature and melting temperature of the PAEKs measured through differential scanning calorimetry in addition to those of other PAEKs reported are approximately proportional to the logarithm of the ratio of the mole fractions of ketone and ether groups in the repeating unit of the PEAKs. On the other hand, this ratio does not affect the crystal structure of the PAEKs.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1022-1336
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The novel poly(aryl ether ketone)s were synthesized by nucleophilic substitution reactions of 4,4′-difluorobenzophenone with 4,4′-biphenyldiol and chlorohydroquinone. As expected, the copolymers have lower melting transitions than the biphenyldiol-based homopoly(aryl ether ketone) because of the copolymerization effect of the crystal-disrupting monomer chlorohydroquinone. Copolymers containing 50 and 70% biphenyldiol show two first-order transitions which are associated with the crystal-to-liquid crystal transition and the liquid crystal-to-isotropic transition.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Macromolecular Theory and Simulations 5 (1996), S. 347-356 
    ISSN: 1022-1344
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The molecular structure and polarizabilities of poly(aryl ether ketone)s were investigated with quantum chemical calculations, based on the fully optimized structures of model compounds (S5: ArCOArOArOArCOAr and BS6: ArOArCOArArCOArOAr) for their chain segments. The results showed that the average dihedral angle between their aromatic rings was in the range of 36°-37° relative to the molecular zig-zag plane. Especially, when a biphenyl group was introduced into the molecular chain of this polymer, its two aromatic rings were distorted by 48.0° to each other. Also, the calculation results of refractive indices for pure crystals obtained by using the structural parameters were in good accordance with those reported in the literature.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 196 (1995), S. 1813-1820 
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A polymeric solid electrolyte having a low glass transition temperature, obtained by complexing LuCIO4 with an acrylic elastomer (AR) containing ester groups in the side chains, shows a conductivity of 2,0 · 10-4 S/cm (LiCIO4: 2,1 mmol/g AR, film thickness: ca. 100-300 μm) at 80°C. From the relationship between ionic conductivity and LiCIO4 concentration, we conclude that LiCI4 dissociates in the acrylic elastomer to produce carrier ions. We also suggest, in regard to temperature characteristics of ionic conductivity and reciprocal dielectric relaxation time, that the driff of ions is related to the motion of acrylic elastomer chains. The carrier mobility in the acrylic elastomer-LiCIO4 complex was measured by using the voltage polarity reversing method. The carrier mobility increased with increasing LiCIO4 concentration and temperature.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 197 (1996), S. 1495-1502 
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Poly(ether ether ketone) (PEEK)/poly(ether sulfone) (PES) block copolymers were synthesized via condensation reaction between fluorine-terminated PEEK oligomers and hydroxyl-terminated PES oligomers. The dynamic mechanical behavior of a composite sample prepared by compression molding of a glass fibre cloth and the copolymer was investigated by means of a dynamic viscoelastometer. The β relaxation peak and the α′ relaxation peak were observed in the logarithmic decrement curve of the amorphous block copolymer of PEEK/PES. The glass transition temperature (β relaxation peak) is shifted to higher temperature and approaches a constant value as annealing time and degree of crystallinity increase. The glass transition temperature of the copolymer rises more slowly upon annealing with increasing PES content. The α′ relaxation peak becomes smaller upon annealing, and eventually disappears. The α′ relaxation peaks are related to the motion of molecules upon transition from the non-crystalline to the crystalline state. The α′ relaxation occurs for the copolymer with a degree of crystallinity of 0 to 3%.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Thermal properties of poly(ether ether ketone ketone) (PEEKK)/poly(ether biphenyl ether ketone ketone) (PEDEKK) copolymers were investigated by means of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The glass transition temperature (Tg) increases from 154°C to 183°C as the content of PEDEKK units increases. The melting point (Tm) of the copolymers varied in the range between 314°C and 409°C and showed the behavior of eutectic type copolymer. From the investigation of the crystallization behavior of the copolymers, it was found that the cold-crystallization temperature (Tc′) of the amorphous copolymers assumes a maximum value for the copolymer with a mole fraction of the PEDEKK segment (nB) of about 0.6, isothermally crystallized PEEKK and the PEEKK/PEDEKK copolymer exhibit double-melting behavior.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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