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  • Electronic Resource  (21)
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  • Electronic Resource  (21)
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  • 1
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract. The novel poly(aryl ether ketone)s containing chloro-side group were synthesized by nucleophilic substitution reactions of 4,4′-biphenol and chlorohydroquinone with either 4,4′-difluorobenzophenone (BP/CH/DF) or 1,4-bis(p-fluorobenzoyl)benzene (BP/CH/BF) and their thermotropic liquid crystalline properties were characterized by a variety of experimental techniques. The thermotropic liquid crystalline behavior was observed in the copolymers containing 50 and 70% biphenol. Melting transition (Tm) and isotropization transition (Ti) both appeared in the DSC thermograms. A banded texture was formed after shearing the sample in the liquid crystalline state. The novel poly(aryl ether ketone)s had relatively higher glass transition temperature (Tg) in the range of 168 ∼ 200 °C and lower melting temperature (Tm) in the range of 290 ∼ 340 °C. The thermal stability (Td) was in the range of 430 ∼ 490 °C.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    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: Röntgendiffraktometrische Untersuchungen und DSC-Messungen an Blend-Filmen, die aus Lösungen von PEEK und PES hergestellt wurden, zeigen eine Phasenseparation bei den Filmen, die bei 340°C hergestellt wurden. Das Kristallisationsverhalten von Filmen, die bei 340°C hergestellt, anschließend abgeschreckt und bei 180°C getempert wurden, ist identisch mit dem von PEEK. Filme, die bei 300°C hergestellt wurden, kristallisierten erst durch Tempern bei 250°C. Blockcopolymere, die aus Oligomeren von PEEK und PES erhalten wurden, unterscheiden sich in dieser Hinsicht von Blends der gleichen Zusammensetzung. Die Glastemperatur von Copolymeren mit einem PEEK-Gehalt von mehr als 50% liegt höher als die von PEEK selbst, während der Schmelzpunkt dieser Copolymeren niedriger als der von PEEK ist.
    Notes: Polymer blends of PEEK with PES were prepared by the solution blending method. Copolymers composed of PEEK and PES components were synthesized from these oligomers. The formation conditions exerted an influence over the molecular aggregation and the crystallization behaviors of the blend films and block copolymers which were examined by X-ray diffractometry and DSC analysis. As a result, phase-separation in the blend films was found when the formation temperature was high. The blend films formed at 340°C, quenched and annealed at 180°C, exhibited the same crystallization behavior as those of PEEK. In the case of the blend films formed at 300°C, the annealing of the films at 250°C was required to crystallize the blend films. The Tg of a copolymer with a PEEK component content of more than 50% tends to shift toward a higher temperature than the Tg of PEEK itself, and the Tm of the copolymer toward a lower temperature than that of PEEK ist.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 171 (1989), S. 119-130 
    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 aus Lösung hergestellten Polymermischungen zeigen den Typus der vollmischbaren Polymerlegierungen. Proben, die durch Formpressen der Polymermischungen unterhalb des Schmelzpunkts von Polyetheretherketon (PEEK) erhallten wurden, zeigen ein für mischbare Polymerlegierungen typisches viskoelastisches Verhalten. Hingegen zeigt sich bei Mischungen, die oberhalb des Schmelzpunktes von PEEK verpreßt wurden, im dynamisch-viskoelastischen Verhalten eine Phasentrennung.
    Notes: The polymer blends obtained by the solution blending method show a type of compatible polymer blends. The samples obtained by compression molding the polymer blends below the melting point of the polyetheretherketon (PEEK) exhibit dynamic viscoelastic behavior characteristic of compatible polymer blends, but those by compression molding above the melting point of the PEEK show a phase separation in dynamic viscoelastic behavior.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 6
    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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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 163 (1988), S. 115-126 
    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 Bildung zwischenmolekularer Excimer-Gruppen wurde bei Polyethersulfon (PES) in Dichlormethan-Lösungen bei Konzentrationen um 2,7 × 10-2 mol/l durch Fluoreszenzanalyse nachgewiesen. Die Bestrahlung mit Licht ermöglichte auch die Bildung intramolekularer Excimer-Gruppen; dabei legen sich Molekülsegmente parallel, obwohl die Moleküle recht starr sind. Aus Aufnahmen mit dem Elektronenmikroskop wurde gefolgert, daß Polyethersulfon bei längerem Erhitzen auf 200°C von einem amorphen in einen geordneten Zustand übergeht.
    Notes: Formation of intermolecular excimers in polyethersulfone (PES) dichloromethane solutions were observed at a PES concentration about 2.7 × 10-2 mol/l by the fluorescence analysis. External light energy irradiation enabled the formation of intramolecular excimers in the PES dichloromethane solution. These chains can gain an access to each other in parallel though the molecular chains are considerably rigid. The electron micrograph of the PES film, heat treated at 200°C for 72 hours, presented a diffraction micrograph, which suggests that the PES molecular aggregation is changed from a randomly coiled amorphous phase to an ordered one.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 8
    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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  • 9
    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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  • 10
    ISSN: 1022-1336
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The evolution of crystallinity and polymorphism during hot-drawing of amorphous poly(ether ether ketone ketone) (PEEKK) as a function of strain rate, draw ratio, and temperature was investigated. In modification I, the competition of chain extension and molecular alignment is responsible for the strain rate and temperature dependence. Modification II crystallization is basically controlled by chain extension during stretching. The former can be transformed into the latter via relaxation during stretching or annealing at elevated temperature.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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