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  • Polymer and Materials Science  (18,446)
  • ddc:551.7
  • 1985-1989  (16,449)
  • 1950-1954  (2,027)
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Year
  • 1
    Publication Date: 2022-08-04
    Description: Zwei Hauptdünengebiete kommen im Gebiet westlich von Nieuwpoort vor: die Jüngeren Dünen entlang der heutigen Küstenlinie sowie die Älteren Dünen, die in der Nähe der französischen Grenze isoliert in der Küstenebene auftreten und ebenfalls küstenparallel verlaufen. Beide Systeme wurden geologisch und paläontologisch untersucht. Es wird vermutet, daß das Ältere Dünensystem in der Zeit vor 4300 v. h. entstanden ist. Ein Streifen weiterer älterer Dünensedimente (der jedoch nicht so alt wie das Ältere Dünensystem ist) wurde, ebenfalls nahe der französischen Grenze, unter den Jüngeren Dünen gefunden. Das Alter dieser Sedimente liegt zwischen 2800 und 900 v. h. Bei der Entstehung der Jüngeren Dünen wurden zwei Subphasen unterschieden. Vor dem 14. Jahrhundert bildete das Dünengebiet eine relativ ebene Fläche. Ihre Entstehung markiert das Ende einer aktiven äolischen Phase, die im 11. Jahrhundert n. Chr. wahrscheinlich als Folge damals verstärkt auftretender Sturmfluten einsetzte (Dunkerque-3 Transgression). Mit dem Ende des 14. Jahrhunderts begannen sich große Sicheldünen zu bilden, die Teile der früheren Landoberfläche begruben. Einige von ihnen bewegen sich noch heute. Die Entwicklung des Jüngeren Dünengebietes bei De Panne wird eingehend beschrieben, einschließlich der Vegetationsgeschichte des Dünengebietes und der anschließenden Küstenebene. Einige Aufmerksamkeit wird auch der Lage früherer Küstenlinien gewidmet.
    Description: research
    Keywords: ddc:551.7
    Language: English
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  • 2
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    Publication Date: 2022-08-04
    Description: Die Geomorphologische Kartierung des Blattes 8127 Grönenbach machte eine Auseinandersetzung mit den divergierenden Ergebnissen neuerer Untersuchungen zum Altpleistozän des Illergletscher-Gebietes notwendig. Es ergab sich, daß die im Blattgebiet auftretenden altpleistozänen glazifluvialen Bildungen (Ältere und Jüngere Deckenschotter) als im wesentlichen einheitliche, zeitlich nicht zu untergliedernde Schüttungen zu betrachten, und daß die Altmoränen eindeutig in drei Komplexe zu gliedern sind, die der Riß-Eiszeit, der Mindel-Eiszeit sensu Penck 1901 („klassisches" Mindel) und einer weiteren, zwischen klassischem Mindel und Günz einzuordnenden Eiszeit (möglicherweise der Haslach-Eiszeit sensu Schreiner 1981) zugewiesen werden.
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 3
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    Publication Date: 2022-08-04
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 4
    Publication Date: 2022-08-02
    Description: research
    Keywords: ddc:551.7
    Language: English
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  • 5
    Publication Date: 2022-08-02
    Description: Ein Bohrkern aus der südlichen Nordsee (54° 44,5' N, 4° 30' E) wurde auf Pollen, botanische Makroreste, Mollusken sowie Minerale und Schwermetalle untersucht. Im Liegenden befindet sich ein echter Basistorf, auf den ohne Erosion Süßwasser-, Brackwasser- und Salzwassersedimente folgen. Der Transgressionskontakt liegt bei 42,5 m unter Mittelwasser und wurde auf spätes Boreal (etwa 8150 Jahre BP.) datiert, die Profilstelle blieb bis ins Atlantikum im ufernahen Flachwasserbereich. Es folgen nach einem langen zeitlichen Hiatus junge Tiefwassersedimente, die seit oder nach dem Mittelalter abgelagert worden sind. Im obersten Meter steigt der Schwermetallgehalt stark an, was mit der anthropogenen Verschmutzung seit 1880 AD begründet wird.
    Description: research
    Keywords: ddc:551.7
    Language: English
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  • 6
    Publication Date: 2022-08-02
    Description: Erstmals werden rezente Erdknospen und Texturböden aus den Hochlagen eines deutschen Mittelgebirges beschrieben. Untersuchungen der Form, des Substrats und der Frosteffekte belegen ihre Entstehung als Strukturböden. Im Vordergrund der Untersuchung stehen die heutigen Bedingungen für die Weiterentwicklung und Erhaltung der Form. Dem feuchtigkeitsbedingten Aufquellen des thixotropen Substrats im Sommerhalbjahr und der Bildung von Eiskörnchen an Eistagen kommt eine große morphogenetische Bedeutung für die Kleinformen zu.
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 7
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    Publication Date: 2022-08-02
    Description: An drei Orten im nordwestdeutschen Flachlande konnten zwei Interstadiale der Weichseleiszeit festgestellt werden. Vermutlich gehören die Torfe oberhalb des Interglazials von Eversen bei Rotenburg/Hann. ebenfalls einem dieser Interstadiale an (Wolff & Schröder 1940). Die stratigraphischen Verhältnisse lassen eine eindeutige Eingliederung in die Weichselvereisung zu. In allen Fällen liegen die beiden Torfbänke oberhalb des letzten Interglazials und sind in Sanden der letzten Eiszeit eingeschlossen. Von einer Parallelisierung mit den Stadien der Weichselvereisung soll vorläufig Abstand genommen werden. Durch die Pollenanalyse ergab sich eine Unterteilung in eine Birken- und in eine Kiefernphase. Das Klima war subarktisch-ozeanisch. Die Wiedervereisung nach dem letzten Interglazial und den beiden Interstadialen wurde durch ein feucht-kühles, niederschlagsreiches (vermutlich schneereiches) Klima eingeleitet. Beide Interstadiale haben mit der Alleröd-Oszillation gemeinsame Züge, lassen sich jedoch klar von ihr trennen. Ob eine Unterscheidung der beiden Interstadiale mit Hilfe der Pollenanalyse vorgenommen werden kann, ließen die bisherigen Untersuchungen nicht erkennen und muß daher den weiteren Arbeiten vorbehalten bleiben.
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 8
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    Publication Date: 2022-08-02
    Description: research
    Keywords: ddc:551.7
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  • 9
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    Publication Date: 2022-08-02
    Description: research
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    Language: German
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  • 10
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    Publication Date: 2022-08-02
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 11
    Publication Date: 2022-08-05
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 12
    Publication Date: 2022-08-05
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 13
    Publication Date: 2022-08-05
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 14
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    Publication Date: 2022-08-05
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 15
    Publication Date: 2022-08-05
    Description: Daten von Pegelbeobachtungen in Dänemark zeigen zwei verschiedenartige Tendenzen des jährlichen Mittelwasserstandes im Verlauf der letzten 90 Jahre. Stationen im nördlichen Teil des Landes zeigen eine fallende Tendenz (—0.39 mm pro Jahr in Hirtshals), während Stationen im südlichen Teil eine steigende Tendenz (+1.08 mm pro Jahr in Fredericia) zeigen. Dieser regionale Unterschied kann zum Teil durch isostatische Landhebung erklärt werden. Es gibt auch eine ausgeprägte saisonale Änderung im Wasserstand: niedriger Wasserstand im Frühjahr und hoher Wasserstand im Herbst. Beispiele von küstengeologischen Konsequenzen dieser Wasserstandvariationen werden besprochen. Die Diskussion befaßt sich auch mit postglazialen Küstenveränderungen in einem Gebiet, in dem die isostatische Hebung auch noch heute andauert.
    Description: research
    Keywords: ddc:551.7
    Language: English
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  • 16
    Publication Date: 2022-08-05
    Description: Die ältesten Schotter der südlichen Iller-Lechplatte (Hochfirst, Stoffersberg, Plattenberg-Arlesrieder) haben pleistozänes Alter. Während ihrer Akkumulationsphase haben Ur-Iller und Ur-Lech über das gleiche Einzugsgebiet verfugt wie die Gletscher, deren umgelagerte Sedimente die donaueiszeitlichen und jüngeren Schotterkörper aufbauen. Daher ist anzunehmen, daß auch schon während der ältestpleistozänen Biberkaltzeiten im inneralpinen Raum Vereisungen existiert haben. Die Gletscher müssen dabei den heutigen morphologischen Alpenrand erreicht haben. Eine exakte Angabe der ehemaligen Eisrandlagen aus den Bibereiszeiten ist nicht möglich. Sie wären weit südlich der jüngeren donau-, günz-, mindel-, riß- und würmeiszeitlichen Moränen zu suchen und sind der glazialen, fluvioglazialen sowie periglazialen Erosion zum Opfer gefallen.
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 17
    Publication Date: 2022-08-05
    Description: Jessen (1918, 1920, 1936) postulierte die Existenz einer Landbrücke, die das Løkken-Gebiet während des Holozän vom Skagerrak trennte, und Mörner (1969) deutete an, daß drei aufeinanderfolgende positive Seespiegel-Verschiebungen, die seinen PTM-2, PTM-3 und PTM-4 Strandlinien entsprechen, das Gebiet überflutet haben. Neue Befunde, die sich weitgehend auf einen Vergleich von Mikrofossil-Daten (Diatomaceae, Foraminifera und Ostracoda) stützen, bestätigen Jessens Ansicht. Marine Verhältnisse breiteten sich zwischen 8000 v. h. und 5300 v. h. von Süden her vordringend im Løkken-Gebiet aus, und es erfolgte kein Zustrom von stärker salzhaltigen Wässern aus dem Westen. Widerspruchsfreie Beweise für Seespiegelschwankungen wurden jedoch nicht gefunden.
    Description: research
    Keywords: ddc:551.7
    Language: English
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  • 18
    Publication Date: 2022-08-05
    Description: Gehobene holozäne ästuarine Ablagerungen der postglazialen Haupttransgression enthalten in einer Anzahl von Fundpunkten an der Ostküste Schottlands eine charakteristische Schicht vorwiegend aus grauem, glimmerführendem Feinsand. Dort wo die Sedimente sich landseitig mit den ehemaligen Küstenmooren verzahnen, bilden sie im Torf spitz auslaufende Lagen, und auch hier tritt der graue, glimmerführende Feinsand als spitzer Sedimentkeil auf. Diatomeenanalysen deuten auf einen marinen Ursprung hin, Pollenanalysen zeigen eine früh- bis mittelatlantische Florenvergesellschaftung an und C14-Analysen von Torf aus dem oberen und unteren Kontakt deuten auf ein Ereignis von relativ kurzer Dauer um 7000 v. h. Gegenwärtig wird angenommen, daß die Lage entweder auf eine kurzfristig erhöhte Rate des relativen Meeresspiegel-Anstiegs oder auf eine Sturmflut ungewöhnlichen Ausmaßes zurückzuführen ist.
    Description: research
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    Language: English
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  • 19
    Publication Date: 2022-08-05
    Description: Im Verbreitungsgebiet der vom Vulkan El Chichón im Zeitraum März bis April 1982 geförderten Eruptiva wurden 74 Ascheproben entnommen. Die Leicht- und Schwermineralführung der entnommenen Proben wurde quantitativ bestimmt. Mittels eines Computerprogramms wurde für geeignete Minerale ein statistisch gesichertes Verbreitungsmodell erstellt. Dabei zeigt sich, daß die Minerale nach Kornform und spezifischem Gewicht entsprechend der Entfernung vom Ausbruchspunkt sortiert werden. Die Abweichungen der Werte zu den theoretisch berechneten sind in der Nähe des Eruptionszentrums am größten. Das Verbreitungsmuster der Minerale wird in diesem Raum von den Strömungsverhältnissen in der Stratosphäre abgeleitet.
    Description: research
    Keywords: ddc:551.7
    Language: French
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  • 20
    Publication Date: 2022-08-05
    Description: Neuere Kartier- und Bohrergebnisse machen eine teilweise Revision der bisherigen Ansichten über die Ausbreitung des Eem-Meeres notwendig. Nach Dechend (1958) und Sindowski (1958, 1965) erreichte das Eem-Meer während seines Höchststandes ungefähr die heutige Küstenlinie. Im Bereich der ostfriesischen Küste haben die Arbeiten von Barckhausen (1984) und Barckhausen & Streif (1978) einige kleinere Veränderungen des eemzeitlichen Küstenverlaufs ergeben. Im Elbe-Weser-Dreieck muß die Küstenlinie des Eem-Meeres um bis zu 22 km in die Hadelner Bucht verlegt werden. Sie entspricht dadurch der maximalen Ausbreitung des holozänen Meeres vom Subboreal bis Subatlantikum.
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 21
    Publication Date: 2022-08-05
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 22
    Publication Date: 2022-08-05
    Description: research
    Keywords: ddc:551.7
    Language: German
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  • 23
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    Publication Date: 2022-08-05
    Description: research
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  • 24
    Publication Date: 2022-08-05
    Description: research
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  • 25
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    Publication Date: 2022-08-05
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  • 26
    Publication Date: 2022-08-05
    Description: In der Nachbarschaft von Flüssen und größeren Bächen nimmt der Löß sehr häufig eine sandige Beschaffenheit an, in vielen Gebieten ist sogar die Sandkomponente in Form von verschieden starken Schichten (Sandbänder) eingeschaltet. Die vorliegende Arbeit beschäftigt sich in der Hauptsache mit der Lagerung der Sandbänder im vertikalen Profil und mit den Veränderungen in horizontaler Richtung. Auf Grund der allgemeinen Ausbildung und der Körnungsunterschiede des Lößes konnten westlich Königgrätz 4 Faziesbereiche unterschieden werden und zwar die Flugsand-, Bänder-, Übergangs- und Normalfazies. Die 4 Fazieszonen folgen von O nach W aufeinander. Die speziellen Untersuchungen an den Sandbändern führten zu folgenden Ergebnissen: 1. Die Abnahme des prozentualen Anteils der Gesamtmächtigkeit der Sandbänder am Löß erfolgt linear mit dem Logarithmus der Entfernung vom Auswehungsgebiet. 2. Die durchschnittliche Anzahl der Sandbänder je Meter Löß ändert sich mit der Zunahme der Entfernung vom Ursprungsgebiet, wie im einzelnen aus Abb. 10 hervorgeht. 3. Neben der Gesamtmächtigkeit und der Anzahl der Sandbänder wurde auch die Häufigkeit der verschiedenen Mächtigkeitsstufen ermittelt und graphisch aufgetragen (Abb. 11). Dabei ergab sich, daß in unmittelbarer Nähe des Auswehungsgebietes neben wenigen 9 und 10 cm mächtigen Bändern die 2 und 2,5 cm starken überwiegen. In einer Entfernung von etwa 300 m vom Flußufer dominieren die 1 und 1,5 cm starken. Weiter nach W nehmen aber nach und nach die dickeren Lagen wieder zu, so daß am Ende der Sandbänderfazies die 2 und 2,5 cm starken die häufigsten sind. Aus den mitgeteilten Ergebnissen und aus zahlreichen Körnungsanalysen wird geschlossen, daß sowohl die eingelagerten Sandschichten als auch der gößte Teil des Lößes äolischen Ursprungs sind. Sandlagen und Löß wurden durch östliche Winde aus dem breiten Tal der Elbe ausgeweht und auf die benachbarten Höhen transportiert. Dabei gelangte der in Form von Bändern abgelagerte Sand bis zu einer Entfernung von ca. 700 m. Die Kornfeinheit des Lößes nimmt nach W hin immer mehr zu. Weitere Beobachtungen an dem Bystrice- und Cidlina-Tal im W des Untersuchungsgebietes bestätigen die Annahme von der Auswehung des Lößes und der Sandschichten aus den Tälern durch Winde aus östlicher Richtung. Daß die allgemeine Lößverbreitung auch von der Breite der Täler abhängig ist, zeigt ein Blick auf die Karte (Abb. 1).
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    Keywords: ddc:551.7
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  • 27
    Publication Date: 2022-08-05
    Description: Die abschließende Auswertung der Arbeiten zur Aufnahme der Geologischen Karte 1 : 50.000 der Vogesen (Blätter Bruyeres und Epinal) hat bestätigt, daß der mittlere Teil der westlichen Vogesen von zumindest drei aufeinanderfolgenden Vereisungen betroffen war. Vor allem die Randlagen der dritten Vereisung sind in den Tälern von Mosel, Ognon und Moselotte und im Gebiet um Le Tholy nachgewiesen. Unter Bezug auf die für Grand Pile und Les Echets aufgestellten Stratigraphien kann man die dritte Vereisung des Moselbeckens dem Würm-Hochglazial zuordnen. Daraus ergibt sich mindel- bzw. rißzeitliches Alter für die vorausgehenden Vereisungen.
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  • 28
    Publication Date: 2022-08-05
    Description: research
    Keywords: ddc:551.7
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  • 29
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  • 30
    Publication Date: 2022-08-08
    Description: research
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  • 31
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 29-36 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The radical copolymerizations of commercially available cationic monomers (M1) with acrylamide (M2) have been investigated at pH 6.1 in aqueous solutions. The cationic groups in copolymers were analyzed by a colloid titration method and the reactivity ratios were determined by the Fineman-Ross method. The values of r1 and r2 were 1.71 and 0.25 for methacryloyloxyethyltrimethylammonium chloride—M2, 1.68 and 1.26 for N,N-dimethylaminoethylmethacrylate—M2, 1.13 and 0.57 for methacrylamidopropyltrimethylammonium chloride—M2, 1.10 and 0.47 for N,N-dimethylaminopropylmethacrylate—M2, 0.47 and 0.95 for N,N-dimethylaminopropylacrylamide—M2, 0.48 and 0.64 for acryloyloxyethyltrimethylammonium chloride-M2, and 0.58 and 6.7 for dimethyldiallylammonium chloride-M2 systems. The Alfrey-Price Q and e values were calculated and the linear relationship between log Q and ultraviolet absorption maxima of cationic monomers was found.
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  • 32
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Random and alternating thermotropic liquid-crystalline copolyethers have been synthesized from 4,4′-dihydroxybiphenyl and a 1/1 mol ratio of 1,5-dibromopentane and α,ω-dibromoalkanes by a two-phase (organic solvent-aqueous NaOH) phase-transfer-catalyzed polyetherification. Random copolyethers were prepared from α,ω-dibromoalkanes having six to twelve methylene units. Their phase behavior was compared with those of the perfectly alternating copolyethers containing five methylene units in one spacer and eight, nine, or eleven methylene units in the other, respectively. An odd-even dependence in thermal transitions has been observed in both oligomeric systems. In all cases, alternating copolyethers, even though comparatively lower in molecular weight, have given rise to higher melting and isotropization temperatures. Since the increase in the melting temperature is larger than the increase in the isotropization temperature, the thermal stability range of the mesophase has narrowed for alternating copolyethers with respect to their random copolyether counterparts.
    Additional Material: 6 Ill.
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  • 33
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1-14 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of polymercaptans and 2-alkenyl azlactones has been further investigated, and several new multiazlactones which are liquids at room temperature have been prepared and characterized. Michael addition yielding the multiazlactones was found to take place slowly in the absence of and rapidly in the presence of acid catalysts. If basic impurities capable of forming mercaptide ion were present, however, the reaction underwent a substantially different course producing primarily ring-opened products. A source of these basic impurities was determined to be the method of preparation of the alkenyl azlactone itself. When the azlactone was prepared from its acyclic N-substituted aminoacid precursor by cyclodehydration by use of ethyl chloroformate and triethylamine, a small amount of triethylamine remained that dramatically altered the course of reaction. Nonbasic cyclodehydration agents such as dicyclohexylcarbodiimide were effective at eliminating this side reaction, as well as was the practice of adding excess acid to the reaction system to neutralize the basic impurities.
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  • 34
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 37-60 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of carbazola substituted N-acylated polyethylenimines, namely, poly[N-(9-carbazolyl)acetylethylenimine] 20 and poly[N-(2-(9-carbazolyl))propanoylethylenimine] 21 by a grafting reaction onto PEI and isomerization polymerization of the carbazole substituted 2-oxazolines is reported. A complete acylation of amino groups in PEI by the 9-carbazolylacetyl groups was achieved by the p-nitrophenyl active ester method but PEI was only partially N-acylated by the 2-(9-carbazolyl)propanoyl groups under similar reaction conditions. The carbazole substituted 2-oxazolines, namely, 2-(9-carbazolyl)methyl-2-oxazoline 18 and (R,S)-2-[1-(9-carbazolyl)]ethyl-2-oxazoline 19, were prepared by a base induced cyclization of ß-chloroamides. The ring-opening isomerization polymerization of 18 and 19 in the molten state with a cationic initiator (dimethyl sulfate, methyl triflate, or ethylene glycol ditosylate) gave 20 and 21. Gel permeation chromatography of 20 and 21 obtained with different monomerto-initiator ratios gave evidence of a chain transfer reaction with the monomer. The polymers were characterized by elemental analyses, IR, and 1H-NMR spectroscopy.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 75-85 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new route to prepare optically active polyamides was established, based on the polycondensation of two new active diesters: the active diesters of 4-chloro-1 hydroxybenzotriazole, such as 1,1'-(terephthaloyldioxy)bis(4-chloro-benzotriazole), and 1,1'-(isophthaloyldioxy)bis(4-chlorobenzotriazole), with optically active isomers of 2,4-diaminopentane. Dipolar aprotic solvents such as N,N-dimethylformamide and dimethyl sulfoxide were used as reaction solvents. The solution polycondensation carried out in solution at room temperature afforded optically active polyamides. The aminolysis of the two active diesters was carried out as a model reaction study.
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  • 36
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Permeations of water-soluble, ionic fluorescent probes from a large, ultrathin nylon-2,12 capsule membrane were largely affected by the ambient pH of the outer medium; permeations of cationic and anionic probes were accelerated by a factor of 50-100 in the basic and acidic medium, respectively, relative to that in the neutral-pH region. The permeation of NaCl and nonionic fluorescent probes was hardly affected by the ambient pH. The nylon capsule membrane was elucidated to have an asymmetrical structure: the dense-thin inner layer and the porous-thick outer part. The pH-sensitive permeation could be explained due to the ionization of a small amount of residual end-groups (COOH and NH2) existing in the dense-thin inner layer of the nylon capsule membrane.
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  • 37
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 87-96 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The cationic polymerization of p-methylstyrene initiated by acetyl perchlorate at -78°C led to long-lived (living-like) polymers with a narrow molecular weight distribution (M̄w/M̄n = 1.1-1.4) in methylene chloride containing a common ion salt (n-Bu4NClO4) or in a less polar solvent (CH2Cl2/toluene, 1/4v/v). Under these conditions, the number-average molecular weight (M̄n) of the polymers increased in proportion to monomer conversion and was regulated by the monomer-to-initiator ratio. When fresh feeds of the monomer were repeatedly added to a completely polymerized solution, the polymerization ensued at the same rate as before and the linear increase in M̄n with monomer conversion continued. The effects of solvent polarity and the common ion salt on the polymerization showed the suppression of the ionic dissociation of the propagating species, resulting in a “nondissociated species,” to be the key factor for the formation of the long-lived polymers.
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  • 38
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 97-102 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mechanistic features of the reaction with thionyl chloride in pyridine were studied in a model reaction of benzoic acid with p-chlorophenol or aniline. The yields were significantly affected by the amounts of pyridine, favorably by four equivalents, and the nature of pyridine, suggesting that pyridines are not only HCl scavengers, but are also involved in the reaction itself. The reaction was assumed to proceed via a carboxylic sulfinic-anhydride intermediate different from acyl chloride, and the intermediate was found to be not so reactive that it was completely alcoholyzed by the phenol at high temperatures of more than 60°C. The reaction was successfully applied to the preparation of aromatic polyesters of high molecular weights by the direct polycondensation of aromatic dicarboxylic acids and bisphenols in pyridine at 80°C.
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  • 39
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 103-107 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel silicon-containing poly-1,2,4-triazoles have been synthesized by the reaction of polyhydrazide precursors and aniline in polyphosphoric acid (PPA) at 260°C. The polyhydrazide intermediates were prepared from aromatic dihydrazides and silicon-containing acid dichlorides via interfacial polycondensation. These polymers and their intermediates were characterized by infrared spectroscopy (IR), solubility, and by solution viscosity. The thermal behavior of these polytriazoles has been studied by dynamic thermogravimetry.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 109-118 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Molecular weight distribution of Nylon 12 was determined with hexafluoroisopropanol/toluene mixture as eluent by gel permeation chromatography. Calibration curve for Nylon 12 was easily obtained from that of polystyrene because the method of universal calibration was applicable among these polymers. The molecular weight distributions of Nylon 12 were always broader than expected by the theory of polymerization, i.e., most probable distribution. This result was not caused by broadening effect in gel permeation chromatography, but by polymerization itself.
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  • 41
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    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A polymethacrylate derivative containing 6-cyanouracil was prepared, and its photochemical reaction was studied. The 6-cyanouracil derivative was found to show high reactivity for the photochemiccal reaction. The photochemical-reaction product was identified as a cyclobutanetype photodimer, and the photodimer was formed in high yield even from the monomeric compound of 6-cyanouracil under UV irradiation in low concentration. The quantum yield of the photodimerization of the 6-cyanouracil derivative was greater than that of the thymine derivative. The photodimerization of the 6-cyanouracil derivative could not be quenched by usual triplet quenchers, but was found to be quenched by the polymeric derivative of adenine, suggesting a specific interaction.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 147-153 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Piperidinium dithiobenzoate and piperidinium tetrathioterephthalate react with α-halo carbonyl compounds to give small molecules and polymers which, upon dehydrative cyclization with H2SO4, yield materials containing the 1,3-dithiolium ring. Maximum yields are obtained by use of phase-transfer techniques and the solvent system H2O/CH2Cl2. The cyclized polymers are soluble in sulfuric acid, and films can be made from (CF3)2 CHOH solutions.
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  • 43
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 133-145 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ortho-vinylbenzaldehyde has been prepared in a three-step synthesis. Vacuum-degassed monomer was polymerized with azodiisobutyronitrile initiator in bulk and in solution in 2-butanone. The kp/kt1/2 value at 60°C is 4.7 × 10-2 L1/2 mol-1/2s-1/2. This is about twice the ratio for styrene. Chain transfer to monomer appears to be significant. Insoluble, crosslinked products were produced at high conversions, because of chain transfer to polymer. Tg of poly(ortho-vinylbenzaldehyde) was found to be 142°C.Polymers made under N2 atmosphere often contained acetal groups. These can be produced by acid catalysis in the presence of small concentrations of ortho-vinylbenzyl alcohol. A laddertype structure is produced.The monomer is capable of photoinitiation. Insoluble gels were produced in bulk monomer at all conversions. The initiation rate was very high and crosslinking resulted from combination of radicals produced from photolysis of the pendant 0-benzaldehyde groups in the macromolecules.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 167-171 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
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  • 45
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 155-165 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The initiating ability of the graphite intercalation compounds (GICs) of SbCl5, FeCl3, and AlBr3 was investigated. It was found that GICs were able to initiate the polymerization of monomers of different types-cyclosiloxanes, 1,2-epoxides, vinyl ethers, lactones, and vinyl monomers. GICs of SbCl5 initiated also the polymerization of tetrahydrofuran. The interaction of the monomers (with the exception of the lactones) caused a size increase of the GICs and deformations in their lamellar structure. Relatively high-molecular poly(vinyl ethers) and polydimethylcyclosiloxanes were obtained. The mechanism of action of GICs was discussed.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 173-185 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrolyses of B-triamino-N-triphenyl-, B-triamino-N-trimethyl-, and B-trianilino-borazines were performed between 150 and 300°C. Initial stages of degradation were accompanied by liberation of ammonia in addition to the expected aniline or methylamine; this was most pronounced for the methyl borazine. Aniline elimination proceeded more readily with the B-anilino than the B-amino isomer. Data obtained support a ring opening mechanism resulting in telomerizaton accompanied by aniline liberation and formation first of singly then doubly bridged dimers and finally doubly bridged tetramers. Thermal exposure up to 1000°C failed to give pure boron nitride; carbon was invariably retained.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 187-189 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 191-194 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 197-202 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Radical polymerications including co- and terpolymerizations of a γ-methylene-Δα,β-butenolide derivative, ethyl (E)-5-oxo-2,5-dihydrofuran-2-ylideneacetate(EODY) was investigated. The monomer had no homopolymerizability but copolymerized with styrene (ST) and 1,3-cyclohexadiene to yield alternating copolymers. From IR and 1H-NMR spectra of the copolymers, the 1,4-addition was confirmed to exclusively occur for the conjugated double bond of EODY. Terpolymerization for the system involving an acceptor monomer such as maleic anhydride, α-chloromaleic anhydride, or 7,7,8,8-tetracyanoquinodimethane in addition to ST and EODY gave the terpolymer containing about 50 mol% of ST, in spite of a high fraction of ST in the feed. It was inferred that such an apparent behavior of EODY as an acceptor monomer could be due to a resonance-stabilization of the propagating radical having EODY as a terminal unit, which is also responsible for the poor yields of the copolymers and terpolymers.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 203-213 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two sytrene derivatives formylstyrene and styrene sulfonylcholoride, were synthesized. Polymeric microspheres in diameters ranging from 0.1 to 2 μm were synthesized by polymerization of chlormoethylstyrene, formylstyrene, and styrene sulfonylcholoride in organic solvents, in the presence of appropriate surfactants. The kinetics of microsphere formation were studied. The molecular weight distribution of the products was determined by gel permeation chromatography. Conditions for binding various amino ligands to the microspheres were also established.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 241-253 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 3-[(4-Azidophenyl)dithio]propionic acid (1a) was prepared in four steps from 4,4′-diamino-diphenyldisulfide. Attachment of 1a to poly[(3-hydroxypropyl)oxirane] was accomplished under very mild conditions via an acid-catalyzed caarbodiimide coupling. Photolysis of polymer-bound 1a with an electronic flash unit proceeded without detectable disulfide bond cleavage. Mild reduction of the disulfide bond of an analogue of 1a which carried no azido group confirmed that 1a should be useful in photolabeling studies of polymer-cell surface interaction.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 269-278 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new route to polyamides containing optically active thymine groups as pendants has been established. The method is based on the grafting of (-) and (±)-2-(thymin-1-yl)propionic acid [(-) and (±) TPA] onto a polyamide containing hydroxyl groups. The hydroxy polyamide was prepared by selective N-acylation of an active diester of N-hydroxy-5-norborene-2,3-dicarboxamide (HONB), N,N'-(isophthaloyl-dioxy)-bis(5-norbornene-2,3-dicarboximide) (IPBONB), with 1,3-diamino-2-hydroxypropane (AHP). Model compounds (-) and (±)-(1,3-dibenzoylamino-2-propyl)2-(thymin-1-yl)propionate[(-) and (±) (BAPTP)] were prepared by direct, low-temperature esterification before synthesizing the polymer.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 215-240 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermal effects accompanying the vacuum deposition of poly-para-xylene (Parylene N) at different temperatures have been studied by following the changes in the temperature of the substrate. Similarly to the case of polychloro-para-xylylene (Parylene C), two distinct exothermic effects were observed; one discrete, resulting in sharp exothermic spikes and the other continuous, resulting in the shift of the baseline. The spike effect, attributed to the solid-state polymerization of para-xylylene, is observed at the low-temperature range, the upper limit of which moves higher for higher deposition rates. The shift of a baseline as a function of deposition temperature exhibits two maxima, one independent of deposition rate and the second moving toward higher temperatures (that is, toward the first maximum) for higher deposition rates. First maximum falls at about —72°C and is attributed to the melting point of para-xylylene crystals. X-ray diffraction studies of polymer samples have shown that the existence of the second maximum is always followed by the appearance of an additional crystalline phase in the respective range of deposition temperatures. When the deposition rate is high enough, the second maximum merges with the first one, or virtually disappears. Under such conditions the new crystalline phase is no more detectable. It is postulated that the evolution of the additional amount of heat resulting in the appearance of the second maximum is due to the cyclization reaction and the formation of cyclic oligomers. This reaction very likely requires a particular spatial arrangement of monomer molecules and, therefore, it is suggested to take place in certain domains of the crystalline lattice.
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  • 54
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    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyphenylenes made by reaction of benzene, biphenyl, or p-terphenyl with metal halide catalyst-oxidant systems are complex mixtures of dissimilar oligomers, which include halogenated and polynuclear structures, according to positive and negative-ion laser desorption/Fourier transform mass-spectral analyses. Polymerization of benzene with metal-chloride salts that terminate chain elongation by chlorination of the end rings appears to decrease formation of polynuclear structures by providing a competing pathway for chain termination. Polynuclear structures occur to a greater extent with oligomerization of biphenyl than with benzene, presumably because of isomerization and increased opportunity for π overlap during propagation. Electrical conductivities of polyphenylenes made by various routes should not be discussed solely in terms of the linear poly(p-phenylene) structure.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 279-286 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 301-316 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal degradation of poly(vinyl bromide) (PVB), poly(vinyl chloride) (PVC), poly(vinyl alcohol) (PVA), poly(vinyl acetate) (PVAc), poly(vinyl fluoride) (PVF), poly(vinylidene chloride) (PVC2), and poly(vinylidene fluoride) (PVF2) has been studied by direct pyrolysis-mass spectrometry (DP-MS) and flash pyrolysis-gas chromatography-mass spectrometry techniques. Vinyl and vinylidene polymers exhibit two competitive thermal degradation processes: (1) HX elimination with formation of polyene sequences which undergo further moleculaar rearrangements, and (2) main-chain cleavage with formation of halogenated or oxigenated compounds. The overall thermal degradation process depends on the prevailing decomposition reaction in each polymer; therefore, different behaviors are observed. The thermal degradation of polyacetylene (PA) has also been studied and found important for the elucidation of the thermal decomposition mechanism of the title polymers.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1487-1495 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly(4-vinylphenylacetate-co-maleic anhydride) was synthesized by free-radical initiation to yield a 1:1 copolymer over a 0.2-0.8 mole fraction range of monomer feed in maleic anhydride. Evidence of 1:1 charge transfer complex between 4-vinylphenylacetate and maleic anhydride was obtained in the UV region at 355 nm. The 13C NMR chemical shifts and 1H NMR integration data indicate that poly(4-vinylphenylacetate-co-maleic anhydride) has an alternating and stereoregular structure. The molecular weight of poly(4-vinylphenylacetate-co-maleic anhydride) was controlled by using specific solvents and initiator concentrations.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1505-1510 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 3-Methyl-1-butene (3M1B) was found to undergo monomer-isomerization copolymerization with 2-pentene (2P) in the presence of Ziegler-Natta catalyst to give a copolymer exclusively consisting of 3M1B and 1-pentene (1P) units, the same as that obtained from copolymerization of 3M1B and 1P. The apparent copolymerization parameters were determined. The amount of 3M1B unit incorporated in the copolymers was found to increase in the copolymerization system of 3M1B-2P more than in that of 3M1B-1P. The polymers consisting of nearly complete 3M1B units were produced at a rapid rate through monomer-isomerization copolymerization of 3M1B with 2P in the presence of TiCl3 - (C2H5)3Al catalyst.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1529-1537 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Various feed ratios of 2,2′-bithiophene (BT) and pyrrole (PY) were electropolymerized to low conversion and the polymers analyzed for their mer ratios. The polymeric product was rich in polypyrrole (PPY), but the composition could be varied by control of the electrode potential. The increase in BT content is not linear with composition, and the physical evidence indicates oxidative copolymerization and not the formation of the two homopolymers. The data can be interpreted on a copolymerization equation despite the absence of steady state conditions. Sets of reactivity ratios were determined for the polymers formed at two potentials. The electrical efficiencies for polymer formation approach stoichiometric values for oxidative polymerization.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1565-1575 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vinyl monomers bearing N-substituted phenoxazine or 2,8-dimethylphenoxazine units were synthesized starting with the corresponding phenoxazines. N-substituents were 2-vinylbenzyl-oxycarbonylethyl group prepared via 2-carboxyethyl group, 3-methacrylamido-, 3-acrylamido-, or 3-(4-styrenesulfonamido)-propyl group prepared via 3-aminopropyl group, vinylbenzyl, or 2-vinyloxyethyl group attached by the displacements of sodium salts of the phenoxazines to the chlorides, and 2-methacryloyl- or 2-acryloyl-oxyethyl group prepared via 2-hydroxyethyl group. Free-radical polymerixations of these novel monomers proceeded smoothly, except those with 2-vinyloxyethyl group, which were susceptible to BF3-etherate. Changes of the visible absorption spectrum of iodine in THF with addition of the monomers and polymers were considerable, with the appearance of new absorption peaks or shoulders in major cases.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1585-1597 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Separation of water-ethanol mixture through a membrane was carried out by pervaporation using a membrane which provided a hydrogen-bonding interaction. A membrane obtained from poly(acrylic acid-co-acrylonitrile) was effective for a selective separation of water from aqueous ethanol solution by pervaporation technique. Spectroscopic and flux analyses verified that this high selectivity toward water was attributed to the hydrogen-bonding interaction between water and acrylic acid (carboxylic acid) unit in the membrane. On the other hand, a membrane from poly(acrylic acid-co-styrene) preferentially permeated ethanol in the low water feed concentration region.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1657-1674 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nylons containing carbonyl groups in backbone chains were prepared and their response to heat was studied. The carbonyl groups were introduced using either HOOC(CH2)4CO(CH2)4COOH or H2N(CH2)5CO(CH2)5NH2 in the initial monomer compositions. In addition to pyrolysis of these polyamides, the progress of chemical and physical changes as a function of temperature was continuously monitored and analyzed by FT-IR spectroscopy on cast films placed in an environmental chamber. Introduction of the carbonyl groups into the polymer backbone resulted in a significant reduction of the thermal stability of the corresponding polyamide. Possible mechanisms for the thermal degradation entailing these carbonyl groups and N-acylamide compounds are discussed.
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  • 63
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1703-1716 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new class of poly-conjugated polymers has been obtained by condensation of anthraquinones with aromatic diamines in polyphosphoric acid. The polymers are black, intractable powders. Toward obtaining tractable materials, the effect of monomer structure on polymer tractability has been studied. Copolymerizations were also carried out to “soften” these materials. Electrical conductivities in the semiconducting range, 10-4- 10-8 (ohm cm)-1 were observed. Doping with iodine showed small increases.
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  • 64
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 389-403 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics and mechanism of H2O and CO2 evolution during uncatalyzed and copper(oxide)-catalyzed (Cu, CuO, CuO0.67) oxidation of isotactic polypropylene have been investigated in detail for various catalysts over a range of temperatures (90-150°C). These volatiles were determined chromatographically; H2O and CO2 represent the main volatiles of the oxidation, comprising about 80 mol % of all volatiles. Uncatalyzed oxidation evolves ca. 1 mol of H2O and 1 mol of CO2 for each unit mole of polymer oxidized, while catalyzed oxidation produces 2 mol of H2O and ca. 1.2 mol of CO2 for each unit mole of polymer. These results indicate that secondary as well as tertiary H atoms on the polymer chains are involved in hydroperoxide formation and decay. The oxidation mechanism has been formulated and evaluated on this basis. It consists essentially of two parallel oxidation reactions involving tertiary and secondary groups (H atoms and hydroperoxides), respectively. The mechanism can be represented by first- and pseudo-first-order reactions in series: (1) oxygen absorption showing induction periods; (2) hydroperoxide formation and decay (plateaus are reached); (3) H2O evolution from the decay of hydroperoxides; and (4) subsequent CO2 production involving chain scission. Arrhenius parameters for all oxidation reactions (uncatalyzed and catalyzed) are also presented. It appears that CuO0.67 is the most efficient catalyst of those investigated.
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  • 65
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 469-481 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of addition reactions between methyl α-eleostearate which forms the main chain of tung oil and phenol when catalyzed by an acid, p-toluene sulfonic acid, have been studied. The addition reactions, carried out with phenol was shown to be second order with regard to methyl α-eleostearate concentration and first order with regard to phenol concentration. The reactions were additions of two phenol molecules to one methyl α-eleostearate molecule, and it was presumed that they proceed in the two steps given below in which the first step is rate determining: (1)\documentclass{article}\pagestyle{empty}\begin{document}$ 2{\rm E} + {\rm P} \to [{\rm X}]({\rm intermediate}) $\end{document} (2)\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} [{\rm X}] + 3{\rm P} \to 2{\rm P - E - P} \\ \left( {_{{\rm P : phenol}}^{{\rm E : methyl }\alpha {\rm - eleostearate}} } \right) \\xb \end{array} $$\end{document} The apparent reaction rate constant (l/mol min) was found to be 0.036 and its value was nearly equal to that in the case of m-cresol. The apparent activation energie (kcal/mol) was found to be 4.76 and its value was larger than that in the case of m-cresol.
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  • 66
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1633-1642 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 5-Phenyl-2-pentene (5Ph2P) was found to undergo monomer-isomerization polymerization with TiCl3-R3Al (R = C2H5 or i-C4H9, Al/Ti 〉 2) catalysts to give a polymer consisting of exclusively 5-phenyl-1-pentene (5Ph1P) unit. The geometric and positional isomerizations of 5Ph2P to its terminal and other internal isomers were observed to occur during polymerization. The catalyst activity of alkylaluminum examined to TiCl3 was in the following order: (C2H5)3Al 〉 (i-C4H9)3Al 〉 (C2H5)2AlCl. The rate of monomer-isomerization polymerization of 5Ph2P with TiCl3-(C2H5)3Al catalyst was influenced by both the Al/Ti molar ratio and the addition of nickel acetylacetonate [Ni(acac)2], and the maximum rate was observed at Al/Ti = 2.0 and Ni/Ti = 0.4 in molar ratios.
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  • 67
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1675-1683 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerizability of a variety of mono- and multi- nitriles in the presence of free radical initiators at high temperature is determined by the concentration of available cyano-groups. Mononitriles do not polymerize, but multinitriles do so readily. If alkyl substituents are introduced in a molecule that easily polymerizes, this concentration and the ability to polymerize are lowered; if several or bulky substituents are introduced, the polymerization is completely prevented. Multinitriles containing ester groups undergo decarbomethoxylation in these polymerizations. The polymers are black and highly insoluble. From the few reactions that were attempted on these polymers, we can conclude that the structure is probably not the simple conjugated imine structure proposed by earlier investigators, but more experiments are needed to prove this point. The black polymers had conductivities less than 10-9 Ω-1 but, after heating at 700°C, conductivities in the range from 10-3 to 10-6 Ω-1 are observed.
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  • 68
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    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymerization of new 1-(trimethylsilyl)-1-propyne homologs containing two silicon atoms [CH3C≡CSi(CH3)2CH2Si(CH3)3 and CH3C≡CSi(CH3)2CH2CH2Si(CH3)3] was investigated by use of Ta and Nb catalysts. CH3C≡CSi(CH3)2CH2Si(CH3)3 was polymerized quantitatively by TaCl5 alone to provide a polymer having molecular weight over 106. CH3C≡CSi(CH3)2CH2CH2Si(CH3)3 was polymerized in good yield by an equimolar mixture of TaCl5 with an appropriate organometallic cocatalyst such as Ph4Sn to give a polymer with molecular weight of ca. 4 X 105. Nb catalysts were less active toward these monomers than the corresponding Ta catalysts. These two kinds of polymers had alternating double bonds along the main chain according to IR and 13C-NMR spectra. Both polymers were white solids completely soluble in low-polarity solvents like toluene, and solution casting afforded uniform, tough films. These polymers were thermally fairly stable, and their softening points were above 350°C. Films of these polymers showed smaller oxygen permeability coefficients [Po2 = 4 × 10-9 - 8 × 10-9 cm3(STP) · cm/(cm2·sec·cmHg)] but larger separation factors [(Po2/Po2) = 3.4 - 3.6] than a poly[1-(trimethylsilyl)-1-propyne] film.
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  • 69
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1879-1894 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fluorescence analysis has been employed as an analytical technique to elucidate the photolysis mechanism of several aromatic diisocyanate-based polyurethanes in solution. Based on a comparison with model arylmonocarbamates and arylbiscarbamates, the photo-Fries rearrangement and cleavage-type products found for the small-model arylcarbamates were also identified for the photolyzed polyurethanes in solution. Viscosity and absorbance change results for photolysis of both air and nitrogen-saturated polyurethane solutions are consistent with a general two-step mechanism for the photolysis of aromatic diisocyanate-based polyurethanes.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1915-1921 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyureas of high molecular weight were obtained by the direct polycondensation of 4-aminophenyl ether with lithium carbonate in the presence of triphenylphosphine (Ph3P), hexachloroethane (C2Cl6), and pyridine. Reaction conditions, such as the molar ratios of Ph3P and C2Cl6 to the monomers, monomer concentrations, reaction temperatures, reaction times, and kind of solvents, had a significant effect on the yield and the molecular weight of the resulting polyureas. The polyurea having the highest solution viscosity of 0.91 dL/g was obtained with the molar ratio of Ph3P/C2Cl6/monomers = 2.4/2/1 in the mixed solvent of N-methyl-2-pyrrolidone and pyridine at 80°C.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1829-1838 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A method for characterizing very large, water-soluble polymers by size exclusion chromotography (SEC) has been developed. Sephacryl S1000 packing material, a precision syringe pump, and an eluent pressure detector have been utilized to produce highly accurate chromatograms of polymers having molecular hydrodynamic diameters up to 250 nm. Previous SEC analysis has been limited to polymers having hydrodynamic diameters of less than 120 nm.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1989-1995 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The stabilized fibers prepared by heating PAN and a PAN copolymer in air and under reduced pressure have been examined by FT-IR spectroscopy in order to determine their chemical structures. Three kinds of reactions, cyclization, dehydrogenation, and oxygen uptake are found to occur almost simultaneously in the stabilization process in air by digital difference spectrum method. The effect of the comonomer is confirmed to accelate the dehydrogenation reaction and also the formation of acridone ring in the thermal stabilization in air by kinetic study.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2027-2031 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2059-2074 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Acryloyl-type polymer fixing 1-β-carbonylethyl-5-fluorouracil residues through D-glucofuranoses via ester bonds was synthesized by means of polymerization of the corresponding monomer and polymer reaction. In order to provide the water-soluble objective polymer, the copolymerization of the acryloyl-type monomer with acrylamide was carried out. The extent of release of 5-FU residues from the copolymer was investigated in the enzyme or nonenzyme system in vitro. Furthermore, the antitumor activities of the water-insoluble homopolymer and water-soluble copolymer obtained were tested in vivo.
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  • 75
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2101-2105 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Wide-angle x-ray scattering from a polyetheretherketone/carbonaceous fiber composite has been resolved using a curve-fit procedure. This resolution yielded under curve areas for crystalline, amorphous, and fiber scatter which could be used as the basis for an estimation of crystallinity.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1895-1913 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nonaqueous dispersions of poly(vinyl acetate) particles stabilized with poly(2-ethylhexyl methacrylate) and labelled with fluorescent dyes in the core and stabilizer polymer phases were prepared. The materials were characterized using a broad range of techniques (NMR, UV, and fluorescence spectroscopy. GPC, particle sizing, and DSC). The data show that dispersion polymerization of vinyl acetate in the presence of stabilizers containing certain fluorescent dye derivatives, instead of unlabelled stabilizer, results in changes in the mean particle size, size distribution, composition, and molecular weights of the colloidal polymer particles. It was found that increasing the amounts of fluorescent groups in the stabilizer resulted in smaller mean particle sizes and larger amounts of irreversibly attached stabilizer. When the average number of labels in stabilizer exceeded one per chain, a new ultra-high molecular weight polymer fraction appeared. The fluorescence spectra for several of these materials are reported. We describe how fluorescence decay curves can be used to assess block formation and local phase separation in particles labelled with phenanthrene groups. These materials are intended to be used for more detailed studies by fluorescence spectroscopy. Those results will be published in due course.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 1933-1942 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Radiation-induced graft polymerization of acrylamide (AAm) onto low-density polyethylene(LDPE) film has been investigated. The appropriate reaction conditions at which the graft polymerization was carried out successfully were selected. It was observed that the grafting process was enhanced remarkably by using distilled water as diluent. In this grafting system ammonium ferrous sulphate (Mohr's salt) was used as inhibitor to minimize the homopolymerization of AAm and the suitable concentration of such inhibitor was found to be 3 wt %. The dependence of the grafting rate on the monomer concentration was calculated to be 2.9 order, regardless of the irradiation atmosphere (N2 gas or under vacuum). When the radiation grafting process was carried out under vacuum, higher degrees of grafting were obtained as compared to those in nitrogen gas or in air atmosphere. Network structure was formed in the graft copolymer and the gel formation was determined in the p-xylene-extracted grafted films. Results showed good evidence that the grafting process takes place by the front mechanism.
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  • 78
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    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparation of new chelating polymers bearing dihydroxamic acid groups and the adsorptive ability for uranium in sea water are described. Chloromethylated polystyrene crosslinked with divinylbenzene was treated with diethyl malonate in N, N-dimethylformamide to give the polymer having diethyl malonate groups. This polymer was then treated with hydroxylamine in methanol to afford the dihydroxamic acid polymer. The presence of hydroxamic acid groups was confirmed by the appearance of IR absorption band at 1680 cm-1. The dihydroxamic acid polymer contained carboxylic acid groups as well as hydroxamic acid ones, and the contents of carboxylic acid and hydroxamic acid groups were estimated from elemental analysis to be 2-3 and 2-4 mmol/g, respectively. The polymer showed the adsorptive ability of 40 μg-U/g in 8 days for uranium in sea water. In addition, the polymer showed the selective adsorptivity for iron, nickel, copper, and zinc as well as uranium. The macroreticular-type polymer showed much higher adsorption rate for uranium in sea water than the gel-type ones did, suggesting that the rate depends on the diffusion of the uranium in the polymer support.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 579-587 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No Abstract
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 567-577 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Precipitation polymerization of acrylamide initiated by a thermal initiator, Vazo-33 (DuPont Vazo Initiator), was achieved at a solvent composition of acetonitrile/water = 4/6 (vol/vol). The polymerization kinetics were investigated in the acrylamide [M] concentration range 0.86-2.27M, Vazo-33 [I] concentration range 1.4-11.0 × 10-4M, and temperature range 30-40°C. Polymerization was carried out in reaction ampules and the rate was determined gravimetrically. Number-average molecular weight was obtained from intrinsic viscosity. The precipitation polymerization rate varied as [M]2.16 and [I]0.44. Number-average molecular weight was proportional to [M]1.22 and inversely proportional to [I]0.31. The overall reaction activation energy was calculated as 17.3 kcal/mol in the temperature range studied. The optimal reaction conditions studied were: acetonitrile/water = 4/6, temperature = 40°C, [M] = 1.95M and [I] = 2.8 × 10-4M. One hundred percent conversion was achieved in 90 min and a polymer with a number-average molecular weight of 1,200,000 was obtained.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 589-594 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of benzoic acid and p-chlorophenol with phosphorus oxychloride (POC) was significantly affected by the presence of metal salt hydrates or a mixture of metal salts and water sufficiently aged. Among metal salts examined, LiCl was most effective for the reaction to give quantitative yield of the benzoate. The reaction was assumed to proceed via a complexation of POC with LiCl monohydrate followed by selective hydrolysis of POC by water bound to LiCl. The reaction promoted by a complex derived from POC and LiCl monohydrate in pyridine was successfully used as a new condensing agent for the synthesis of aromatic polyesters by the direct polycondensation or aromatic dicarboxylic acids and bisphenols. Under favorable conditions for aging of POC with LiCl monohydrate and for addition of bisphenols, polymers of moderate to high molecular weights were obtained in quantitative yield. The reaction was applied with limited success to the preparation of a copolymer of high molecular weight from hydroxybenzoic acids.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 595-602 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Comparative studies on plasma polymerizations of phenylsilane (PhSiH3) and toluene (PhCH3) have been carried out to prepare plasma polymers containing aromatic groups. The IR and ESCA spectra show that PhSiH3 and PhCH3 are subjected to ring-opening reactions in a discharge state to form polymers involving alkyl chains as well as aromatic groups. The ring-opening reactions are more feeble in the PhSiH3 system than in the PhCH3 system, which may be due to stabilization of phenyl-Si bonds in PhSiH3 by contribution of pπ-dπ bonding. Aromatic groups incorporated into the plasma polymers from PhSiH3 are mono-substituted.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 613-620 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several polymers have been prepared from 4,4′-sulfonyldiphenol (SDP) or its bis-phenate salt as the nucleophile in condensation polymerizations. Ester-sulfone-amic acid polymers were of fairly high molecular weight, and could be imidized. Soluble film-forming poly ether-ester-sulfones were prepared from diphenyl ether diacid chloride.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2171-2184 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: DSC and IR data on benzyldimethylamine-catalyzed dicyandiamide-DGEBA prepolymer system have been utilized to investigate the influences of temperature and composition on the curing mechanism. Etherification as a competitive reaction is favored at lower temperature. On the other hand, the reaction pathway of dicyandiamide (DDA) varies with temperature, especially at the first stage of reaction. At 100°C, the reaction of DDA is shown to be essentially the substitution of the hydrogen atoms by ring-opening of epoxy groups, giving rise to N-alkyl cyanoguanidine. But at 140°C or 160°C, the initial reaction of DDA involves a transformation of nitrile groups to imine groups. A greater amount of BDMA and a higher amine-to-epoxy ratio favor the etherification. The glass transition temperature Tg is a complex function of these different mechanisms; higher Tg could be reached with a amino-to-epoxy ratio equal to 0.6 and after a curing cycle including a precure at 100°C.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2209-2215 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In an attempt to modify water-soluble synthetic polymers, graft Copolymerization of methylmethacrylate (MMA) and ethyl acrylate (EA) onto poly(vinyl alcohol), PVA, has been studied by using gamma irradiation from a Co60 source as initiator. The graft copolymerization was carried out in an aqueous medium by the mutual method in air. The effect of total dose and concentration of vinyl monomers on percentage of grafting has been determined. Water plays a significant role in the enhancement of graft copolymerization and the optimum amount of water to afford maximum grafting has been evaluated. The effect of CH3OH on aqueous grafting of MMA and EA by radiation method has been studied. The graft copolymer has been characterized by IR spectroscopic and thermogravimetric methods.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2217-2230 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Decene-1 was polymerized with the CW catalyst and fractionated by precipitation technique. Light-scattering and viscometric measurements on these fractions established the relationship [η] = 5.19 × 10-3 Mw0.77. The unperturbed mean square end-to-end distance is (〈Ro2〉/M)1/2 = (6.17 ± 0.34) × 10-9. Light-scattering data is consistent with a relatively stiff molecule with length of L = 1.75 × 10-5 cm for poly(decene-1) with MW = 397,000. Its mean square radius of gyration 〈Rg2〉 is 2.79 × 10-11 cm.2 The ratio of L2/〈Rg2〉 = 11 is close to the theoretical ratio of 12 for this kind of macromolecule.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 3117-3127 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mannich reactions were used to prepare a series of low-molecular-weight linear polymers from substituted phenols, formaldehyde, and secondary diamines. The physical and spectroscopic properties of these new aminophenol polymers are described and compared with those of the bisphenolic diamines formed as an intermediate step in the polymerization process. The polymers were found to give coloured, water-soluble, metal complexes with copper and iron salts.
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 3089-3099 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ESR spectra of gamma irradiated annealed and quenched forms of polypropylene film have been studied at the temperatures used for post-irradiation grafting experiments with butadiene, described in Part I. On warming from low temperature there is radical loss by termination and some radical transformation to radicals with optimum stability in annealed polypropylene at approximately 45°C. These radicals, which may be allyl type, are sited at the crystal faces, and decay more rapidly at higher temperatures in annealed polypropylene; in quenced polypropylene their concentration never exceeds one third the optimum observed in annealed polypropylene. Correlation with the grafting experiments suggests that allyl radicals are important for long-term grafting. Effects on the ESR spectrum of adding butadiene to the system show that in the long-term butadiene adds exclusively to the allyl radicals and that alkyl radicals still present at that stage are precursors to the allyl radicals. They do not react directly with butadiene presumably because they are sited in the inaccessible crystal core. Experiments at lower temperature show that butadiene does react with alkyl radicals in accessible regions.
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  • 89
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 3171-3176 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The non-Newtonian intrinsic viscosities [η] of poly(γ-methyl L-glutamate) were measured in the helix-coil transition region under various conditions in this work. The helix content fH, which represents the degree of conformational transition, was obtained by using a polarimeter. Our experimental results show that the non-Newtonian behavior of the polypeptide is markedly affected by its conformation; i.e., the non-Newtonian effect becomes larger as fH increases. The effect of external pressure ΔP on [η] was studied carefully; [η] increases with fH when ΔP 〈 1.5 psi, but it decreases when ΔP 〉 1.5 psi and fH 〉 0.8. The reason for this result is considered in the text.
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  • 90
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2867-2875 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An analytical method based on high performance liquid chromatography (HPLC) has been developed to investigate the competing isocyanate reactions under the influence of various catalysts. The kinetics of the model reaction between phenyl isocyanate and n-butanol was studied in acetonitrile at 50°C. Effects of various catalysts such as an organotin compound, dibutyltin dilaurate, and tertiary amines, 1,4-diazabicyclo-(2,2,2)octane,N,N′,N″-pentamethyldiprophylene triamine,N,N′N″-tris(3-dimethyl-aminopropyl)-3-hexahydrotriazine, and N,N,N′-trimethylaminoethyl-ethanolamine on the reaction rate and the formation of reaction products were investigated. The reactions were followed by determining the NCO disappearance using the standard di-n-butylamine back-titration method as well as measuring the formation of various reaction products using the HPLC method. The relative specificity of a catalyst in isocyanate reactions can thus be determined from the profile of the model reaction which depends upon the structure of the catalyst employed.
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  • 91
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2447-2456 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new class of polyazoxyarylethers was prepared by nucleophilic displacement polymerization using an activated dichlorocompound and a bisphenol dianion in anhydrous aprotic solvent. Model reactions were studied with 3,3′- and 4,4′-dichloroazoxybenzene and various phenol and thiophenol salts to find out the reaction conditions for polycondensation. IR, 1H NMR, and elemental analyses were used to establish the structure of the model compounds and the polymers. Thermal analysis indicated that the oxy derivative is less prone to thermo-oxidative degradation than the corresponding thio derivative of polyazoxyarylether. The polymers are crystalline and soluble in halogenated hydrocarbons and polar solvents.
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  • 92
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2507-2515 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N-Vinyl carbazole methyl methacrylate, and the binary mixtures of these monomers were grafted onto cellulose acetate films by taking recourse to Co-60 simultaneous irradiation grafting technique. The effect of various parameters (e.g., solvents, radiation dose, compositions of the monomers, and concentration of the monomers) on the extent of grafting in unitary and binary systems were studied. The optimum conditions for grafting were evaluated. The sensitizing effect of one monomer in the presence of other in the binary system was identified. The relative molecular reactivity and reactivity ratios were computed and these were used in explaining sensitization and the effect of monomer compositions on the extent of grafting in the binary system.
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  • 93
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 691-700 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Both the rate constant of initiator dissociation, kd, and the chain transfer constant, Cx, are determined by monitoring the rates of monomer and transfer agent conversions in a chain polymerization. Statistical analysis that takes into account the errors of experimental variables has been used to treat the kinetic data for the polymerization of styrene initiated by benzoyl peroxide (Bz2O2) in carbon tetrachloride at 60°C. Values of kd and Cx produced by this error-in-variable method (EVM) are in accordance with those reported in literature. More important, the EVM algorithm always results in the smallest standard deviations of estimates, and hence, it is superior to the usual least-squares calculations. Other distinct features of the method are outlined. The initiator efficiency for Bz2O2 is estimated to be 0.72 under the present conditions.
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  • 94
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2609-2618 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It was found that the amount of water absorbed at room temperature in cured tetraglycidyl-4,4′-diaminodiphenyl methane/diaminodiphenyl sulfone epoxy resins increases as the curing time or temperature increases while the amount of tetrahydrofuran-soluble extractables and the room temperature density decreases. These data suggest that the free volume increases with the extent of cure and the resins become more accessible to water. While the driving force for water absorption is the electrostatic attraction between water and the functional groups in the epoxy, the results suggest that equilibrium H2O absorption is determined primarily by unoccupied volume of the epoxy resin.
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  • 95
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: To provide a satisfactory basic understanding of the solvent effect of plasma-initiated polymerization, we have carried out several kinds of polymerizations of various water-soluble vinyl monomers. It has been shown that aqueous solution of such vinyl monomers underwent the polymerizations induced by methyl isobutyrate (MIB) plasma-exposed glass surface. The invisible ultrathin polymer film trapping an active radical species deposited on the plasma-exposed glass surface apparently induced the polymerizations. The efficiency, however, was largely dependent on the solvent used: the solvent can be considered to act as “an initiation-activator” for the lifelike postpolymerization. The nature of the solvent effect was ascribed to the physicomechanical property such as swelling ability and/or solubility toward the ultrathin film formed on the glass surface. Thus it has been suggested that the choice of good-balanced combination between the structural feature of the plasma-induced ultrathin polymer film and the solvent as an initiation-activator is important to achieve activity of a desired solution polymerization.
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  • 96
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 3101-3107 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the carbon fiber production process from polyacrylonitrile (PAN), PAN precursor is heated first in air to secure stabilization in the succeeding carbonization process at higher temperature. The mechanism of the stabilization reaction and chemical structure of the stabilized PAN have been examined by x-ray photoelectron spectroscopy and elemental analysis. The stabilized PAN was determined to have a ladderlike structure consisting of 40% acridone ring, 30% naphtyridine ring, 20% hydronaphtyridine ring, and others. This structure well explains the stability of the polymer in the succeeding carbonization process on carbon fiber production with conjugated π-electron systems over the whole polymer chain and intermolecular hydrogen bonds. A comonomer addition to the precursor was found to accelerate the dehydrogenation reaction in the stabilization process.
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  • 97
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 3129-3137 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of compounds involving a perfluorinated chain and a trichloromethyl group at the end of the chain is carried out by esterifying an alcohol with trichloracetic acid or by adding CCl4 to a perfluorinated alcohol acrylate. Cl3C—CO2—(CH2)2—C6F13 and Cl3C—CH2—CHCl—CO2—(CH2)2—C6F13 are obtained, respectively. These telogens are both used to initiate a polyacrylamide chain, thus allowing the synthesis of new highly hydrosoluble surfactants. The transfer constant of ferric chloride to the polyacrylamide chain can be calculated by studying the kinetics of the telomerization reaction. We found CFeCl3 = 16 at 125°C. Telomers can be prepared in which the polymer chain contains between 10 to 1000 acrylamide units; the degree of polymerization can be precisely predicted according to the amounts of products allowed to react.
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  • 98
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    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 3191-3199 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermal oxidations at 101°C of ethylene-carbon monoxide (E/CO) copolymer and low-density polyethylene (DYNK) were studied over the range of 0-30 mL oxygen absorbed per gram of polymer. Relative changes in reaction rates, chemical composition, and molecular weights of the polymers were observed using oxygen uptake, infrared spectroscopy, and gel permeation chromatography. At comparable oxidation rates, differences in concentrations of most functional groups appeared to be small, except for the IR peak attributed to non-hydrogen-bonded hydroperoxide which was absent in the spectrum of E/CO copolymer. The extent of scission at comparable oxygen absorption was greater in E/CO than DYNK, since ketonic carbonyl groups were oxidized faster than methylene groups.
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  • 99
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 25 (1987), S. 111-125 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We have prepared a number of high molecular weight, soluble, symmetrical dialkyl substituted germanium homopolymers and germanium-silicon copolymers. In solution, the absorption of the homopolymers was ∼ 20 nm red shifted from the crossponding silicon derivatives. This was somewhat unexpected based on theoretical predictions and has been rationalized on the basis of conformational arguments. In the solid state, samples of poly(di-n-hexylgermane) and poly(di-n-octylgermane) are strongly thermochromic. The effect is attributed to the conformational locking of the backbone which is caused by the crystallization of the side groups. In this regard, the germanium derivatives behave similarly to the corresponding silicon polymers, and the convergence of the long wavelength absorptions for both types of polymers is consistent with theoretical predictions. The germanium-silicon copolymers are also strongly thermochromic, but the long wavelength absorption is somewhat blue shifted (8 nm) from the respective homopolymers. As expected, the new germanium homo and copolymers are quite sensitive to light and readily undergo chain scission to produce lower molecular weight materials.
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 25 (1987), S. 181-189 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vinyl acetate-vinyl alcohol copolymers were fractionated in order to obtain their degree of hydrolysis distributions. In the method employed for fractionation, the differences in molecular weight of copolymer did not affect the fractional separation. Degree of hydrolysis distributions was found to be broad, with a pronounced maximum at a low degree of hydrolysis. Viscosity measurements were performed both for the precipitated fractions and unfractionated polymer. The Huggins constant was found to increase with a decrease in the degree of hydrolysis of polyvinyl acetate. These results were interpreted in terms of a polymer molecular association. From values of Huggins constants, comparative information about copolymer “blockiness” is also established.
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