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  • Polymer and Materials Science  (36)
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  • 1
    Electronic Resource
    Electronic Resource
    Durability of radiation-sterilized polymers, XIIIPart XI cf. lit.6.. The effects of nucleating agent on the oxidative degradation of poly(propylene-co-ethylene) (1990)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 174 (1990), S. 131-140 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Bestrahlungsstabilität von statistischen und Blockcopolymeren aus Propen und Ethen (CP, Copolymeres mit 6% Etheneinheiten) mit und ohne Keimbildner (NA) wurde in bezug auf die Bestrahlungssterilisation von medizinischen Gütern verglichen. In beiden Fällen war die Bestrahlungsstabilität von CP in Gegenwart von NA geringer als ohne.Die Zugabe von NA zu CP verbesserte zwar nicht die Transparenz, die Kristallisation erfolgte aber bei höherer Temperatur. Sie hat deshalb den Vorteil kürzerer Formzeiten bei der Produktion von medizinischen Gütern.Die Bestrahlungsinstabilität von CP mit NA rührt von einer unterschiedlichen Kristallstruktur her, weil sich die Form der Spharolite von der des CP ohne NA unterscheidet. Weiterhin wurde durch Chemiluminiszenz-Analyse ein stärkerer oxidativer Abbau in der Probe mit NA beobachtet.
    Notes: The radiation stability of the random and block poly(propylene-co-ethylene) (CP, copolymer with 6% ethylene units) with and without nucleating agent (NA) was compared in relation to radiation sterilization of medical supplies. In both cases, it was found that the radiation stability of CP in the presence of NA was lower than that of CP without NA.Addition of NA to CP did not improve the transparency but the crystallization occurred at higher temperature. Thus, adding NA to CP has the advantage of shorter moulding time in the production of medical supplies.The radiation instability of the CP with NA was due to a different crystal structure, because the spherulite shape differs from that of CP without NA. Furthermore, by the chemiluminescence analysis, a higher oxidative degradation was observed in the sample with NA.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1990.051740111
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  • 2
    Electronic Resource
    Electronic Resource
    Iodine-initiated, solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal. IV. Fractional dissolution of copolymer (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 21 (1977), S. 749-759 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A fractional dissolution on the oxymethylene copolymer obtained by the iodine-initiated, solid-state copolymerization of the tetraoxane-1,3-dioxolane-methylal system has been carried out using a mixed solvent which consists of tetrachloroethane, phenol, and cyclohexanol. On the fractional dissolution, the oxymethylene copolymer was divided mainly into two parts: one was the copolymer containing a larger amount of ethylene oxide unit in its main chain and having lower molecular weight; the other was copolymer containing a smaller amount of ethylene oxide unit and having a higher molecular weight. It was reasonably concluded that in this copolymerization system, the reaction proceeds from the surface to the center of the tetraoxane crystal to give a divided copolymer due to the heterogeneous properties such as copolymer composition and molecular weight.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1977.070210315
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  • 3
    Electronic Resource
    Electronic Resource
    Iodine-initiated, solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal. VI. Studies on copolymer composition (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 3395-3409 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: In order to elucidate the mechanism of copolymerization of tetraoxane-1,3-dioxolane, the consumption rate of 1,3-dioxolane was measured by using gas chromatography, and the copolymer composition was determined by high-resolution NMR spectroscopy and differential scanning calorimetry. It was found that 1,3-dioxolane is rapidly consumed in the early stage of copolymerization if 1,3-dioxolane is added at once. The copolymer thus obtained is characterized by a heterogeneous distribution of 1,3-dioxolane in the copolymer chain. However, if 1,3-dioxolane is added continuously during the progress of the copolymerization, the distribution and content of 1,3-dioxolane in the copolymer chain was found to be very homogeneous.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070231123
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  • 4
    Electronic Resource
    Electronic Resource
    Radiation grafting of α,β,β-trifluoroethylenesulfonyl fluoride onto low-density polyethylene film by simultaneous irradiation method. I. Kinetic study of simultaneous-irradiation grafting (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 36 (1988), S. 55-62 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: α,β,β-Trifluoroethylenesulfonyl fluoride (TFESF) was grafted onto polyethylene (PE) film by a simultaneous-irradiation method. The influences of the grafting conditions were analyzed kinetically. The dependencies of the grafting rate on the dose rates and monomer concentrations ranging from 10 to 75% were found to be of 1 and 0 order, respectively. The overall activation energy for the graft polymerization was 2.05 × 104 J/mol. The grafting rate was found to be independent of the film thicknesses ranging from 25 to 100 μm.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1988.070360105
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  • 5
    Electronic Resource
    Electronic Resource
    Radiation grafting of α,β,β-trifluoroethylenesulfonyl fluoride onto low-density polyethylene film by simultaneous irradiation method. II. Properties of the grafted membrane (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 36 (1988), S. 63-71 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Certain properties of the membranes obtained by simultaneous-irradiation grafting of α,β,β-trifluoroethylenesulfonyl fluoride (TFESF) onto low-density polyethylene (LDPE) were studied. Swelling, water uptake, electric conductivity, and transport number of the grafted membrane were measured, moreover, thermal and chemical stability were investigated. These properties were found to be mainly dependent on the degree of grafting. The electric conductivity and swelling of the membrane at less than ca. 25% grafting were found to be very low because the distribution of ion-exchange groups is heterogeneous as revealed by X-ray microscopy of the grafted films. At more than 25% grafting, the membranes showed good electrochemical and thermal properties, acceptable for the practical use as cation exchange membranes.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1988.070360106
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  • 6
    Electronic Resource
    Electronic Resource
    Synthesis of hydrophilic elastomers by radiation grafting (1987)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 152 (1987), S. 149-158 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die strahleninduzierte Pfropfung von Acrylsäure auf Ethylen-Propylen-Kautschuk (EPR) wurde untersucht. Es wurde gefunden, daß die Pfropfungsgrade bei Zugabe von Alkohol (Methanol und Isopropanol) abnahmen und die Bildung der Homopolymeren verzögert wurde. Bei Zugabe von Alkohol fand Pfropfung auch im Innern des Filmes statt. Die Pfropfungsgeschwindigkeit war sehr stark vom Propylengehalt im EPR abhängig. Die Pfropfungspolymerisation fand bei kleinen Propylengehalten, z. B. bei 22%, leichter statt. Die Stabilität der Radikale mit niedrigeren Propylengehalten war höher als die der anderen. Die Wasseraufnahme der gepfropften Filme stiegen linear mit dem Pfropfungsgrad an.
    Notes: Radiation grafting of acrylic acid (AAc) onto ethylene-propylene rubber (EPR) to obtain hydrophilic elastomers has been investigated. It was found that by addition of alcohol (methanol and 1-propanol) into water as solvent for grafting the degree of grafting increased and formation of homopolymer was retarded. The grafting by addition of alcohol occurred even in deeper portions of the film compared with no addition of alcohol. Grafting rate differed largely with propylene contents in the EPR. Graft polymerization occurred easily in EPR of lower propylene contents such as 22%. Before introducing AAc in grafting the stability of EPR radicals of lower propylene contents was higher in comparison with other components. Water absorption of EPR increased linearly with increasing grafting yield.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1987.051520113
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  • 7
    Electronic Resource
    Electronic Resource
    Radiation grafting of hydrophilic monomers onto poly(4-methylpentene-1), IIPart I, cf. lit.1.. Grafting of long chain monomers and physical properties of the grafted films (1987)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 152 (1987), S. 159-168 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die strahleninduzierte Pfropfung von 2-Hydroxyethylmethacrylat (HEMA) und Methoxytetraethylenglycolmethacrylat (M4G) auf Poly(4-methylpenten-1) (TPX) wurde untersucht. Die Pfropfungsgrade erhöhten sich mit zunehmender Vorbestrahlungsdosis, Pfropfungstemperatur und Monomerkonzentration. Die Pfropfungsgeschwindigkeit ist abhängig von der Kettenlänge der Monomeren; sie nimmt mit wachsender Kettenlänge ab. Bei Bestrahlen der Filme mit Elektronenstrahlen anstelle von γ-Strahlen waren die Pfropfungsgrade höher. Die Zugfestigkeit der gepfropften Filme im trockenen Zustand stieg mit zunehmendem Pfropfungsgrad an, während die Bruchdehnung abnahm. Dagegen nahmen die Zugfestigkeit und die Bruchdehnung im nassen Zustand mit wachsendem Pfropfungsgrad ab, da Wasserstoffbrückenbindungen zwischen den aufgepfropften Ketten durch die Wasseraufnahme der Filme fehlten.
    Notes: Radiation grafting of 2-hydroxyethyl methacrylate (HEMA) and methoxytetraethyleneglycol methacrylate (M4G) on low crystallinity poly(4-methylpentene-1) (TPX) has been investigated. Grafting yield increased with increasing pre-irradiation dose, grafting temperature, and monomer concentration. Grafting rate depends on length of molecular chain in the monomers and decreases with increasing chain length. The grafting yields of electron beam irradiated samples were higher than those of γ-irradiated ones because of higher radical concentration. Tensile strength of the grafted film in the dried state increased and the elongation at break decreased with increasing degree of grafting. On the other hand, in the wet state, the tensile strength and elongation at break decreased with increasing the degree of grafting due to the lack of hydrogen bonds between the grafted chains caused by increased water absorption.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1987.051520114
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  • 8
    Electronic Resource
    Electronic Resource
    Radiation grafting of α,β,β-trifluorostyrene onto poly(ethylene-tetrafluoroethylene) film by preirradiation method. I. Effects of preirradiation dose, monomer concentration, reaction temperature, and film thickness (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 37 (1989), S. 2817-2826 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Preirradiation grafting of α,β,β-trifluorostyrene onto poly(ethylene-tetrafluoroethylene) film was studied. The trapped radicals formed upon irradiation were able to induce graft polymerization under appropriate conditions. The influences of the grafting conditions were analyzed kinetically. The grafting rate dependency on the preirradiation dose was found to be of order 0.3, and the monomer concentrations, 1.0. The overall activation energies for this grafting were calculated to be 6.2 × 104 and 9.3 × 103 J/mol below and above 50°C. The grafting rate was found to be independent of the film thickness, which ranged from 25 to 100 μm.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1989.070371003
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  • 9
    Electronic Resource
    Electronic Resource
    Thermoplastic elastomer by radiation grafting. I. Evaluation of processability of natural rubber grafted methyl methacrylate (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 43 (1991), S. 883-890 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Processability of thermoplastic elastomer (TPE) prepared by radiation-induced grafting of methyl methacrylate (MMA) onto radiation vulcanized natural rubber latex (RVNRL) has been evaluated using a kneader and a hot roll mill at 150°C. It was found that mixing time and revolution rate (rpm) of the kneader have significantly affected the processability. The longer mixing time and the higher revolution rate result in better processability. In such processing conditions, however, the mechanical properties were found to be inferior because the molecular chain scissions occurred during the mixing. A considerable improvement of mechanical properties was obtained when the mixing was carried out without added process oils. Blends of the grafted vulcanized natural rubber latex (RVNRL-g-PMMA) and MMA grafted on unvulcanized natural rubber latex (NRL-g-PMMA) improved processability where the better processability could be achieved at a shorter mixing time and a lower revolution rate. In addition, a comparable value of mechanical properties was obtained.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070430505
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  • 10
    Electronic Resource
    Electronic Resource
    Radiation grafting of α,β,β-trifluorostyrene onto poly(ethylene-tetrafluoroethylene) film by preirradiation method. II. Properties of cation-exchange membrane obtained by sulfonation and hydrolysis of the grafted film (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 38 (1989), S. 2091-2101 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A Study was made on certain properties of the cation-exchange membranes obtained by the preirradiation grafting of α,β,β-trifluorostyrene (TFS) noto poly(ethylene-tetrafluoroethylene) (ETFE), followed by sulfonation and hydrolysis of the grafted film. Swelling, water uptake, electric conductivity, and transport number of the membranes were measured as a function of ino-exchange capacity. Thermal and chemical stability were also investigated. These properties were found to be mainly dependent on ion-exchange capacity. The stable membrane properties were established due to a homogeneous ion-exchange group distribution in the membrane, as confirmed by x-ray imcroscopy analysis of the membrane cross sections. In addition, the membranes showed good electrochemical, thermal, and chemical properties, and were found to be scceptable for practical use as cation-exchange membranes.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1989.070381111
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