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  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 1667-1675 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Effects of ferric chloride (FeCl3) on photodegradation of high-density polyethylene (PE) were investigated by using ESR and infrared spectrometry. In the system with irradiation at light of λ 〉 220 nm, PE irradiated at 77°K yielded an 8-line spectrum, the intensity of which was markedly weakened by using FeCl3 with the sample, indicating a distinct depression of radical formation. On the other hand, PE with the use of FeCl3 yielded radicals under irradiation only with light of λ 〉 300 nm, showing a singlet spectrum with a line width of 15 gauss. For photooxidized PE, almost the same effect of FeCl3 was observed. On irradiation at room temperature, PE samples with and without FeCl3 showed a singlet spectrum with line widths of 15 and 25 gauss, respectively. On the other hand, the unsaturated double bond contained in a small amount in PE sample was observed by infrared study to be decreased with photoirradiation; however, the decrease was sharply depressed with the addition of FeCl3 to the sample. The degradation of carbonyl group in a photooxidized sample was markedly affected by photoirradiation, and the decay was obviously reduced for the sample on addition of FeCl3. It is concluded that FeCl3 works upon photodegradation of PE to enhance the Norrish type II reaction and to accelerate the formation of unsaturated double bond in the chain.
    Additional Material: 8 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 2707-2720 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photoreactions of maleic anhydride (MAH) with unsaturated olefinic polymers such as 1,2-polybutadiene, 1,4-polybutadiene, block copolymer of styrene and butadiene, polystyrene, poly(styrene-co-isoprene), and poly(styrene-alt-methyl methacrylate) were investigated in air. When the polymers have olefinic unsaturation, the addition of MAH to the polymers in homogeneous solutions proceeded efficiently by a chain mechanism, and the quantum yield of the photoaddition of MAH was greater than unity under irradiation at λ 〉 310 nm. From the effects of solvent and photosensitizer, a radical chain mechanism involving crosslinking of the polymers by MAH molecules was suggested. Together with the spectroscopic results, the reaction mechanism was discussed. The photoaddition reaction was then applied to the surface photomodification of polymer films. Photoreactions were conducted at the interphase between solid polymer and acetone solution of MAH and also at the interphase between solid polymer and gaseous MAH. Irradiation by a 300-W high-pressure mercury lamp could bring about considerable modification of the surface properties of the polymers, which then show improved wettability and dyeability. From the oxygen permeation experiments, the present interfacial phototreatment was shown to provide a double-layered polymer film in which one side of the film is polar and hydrophilic while the other side is nonpolar and hydrophobic.
    Additional Material: 10 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 2865-2873 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The influence of ferric acetylacetonate [Fe(acac)3] on the photodegradation of model compounds of polyethylene (PE) was examined. By studying electron-spin-resonance (ESR) spectra of photoirradiated compounds such as 1-octene and 1,7-octadiene, which contain carbon double bonds, Fe(acac)3 was found to accelerate the formation of allyl radical by contact with them. On the other hand, Fe(acac)3 suppressed the radical formation based on Norrish type I reaction in a carbonyl group of compounds such as 2-octanone and 3-octanone. Based on the study of ultraviolet (UV) spectra as well as ESR spectra on photoirradiated samples, the influence of Fe(acac)3 on the photodecomposition of model compounds of PE was discussed. Finally, the discussion turned to the mechanism of photodecomposition of PE in the presence of ferric salt.
    Additional Material: 8 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 21 (1983), S. 1535-1542 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Catalytic hydrolysis of enantiomeric substrates by N-decanoyl-L-histidine was studied at pH 7.30, 0.02M phosphate buffer, and 25°C in the presence of quaternized polymers. The rate of reaction is remarkably accelerated in the presence of polyethylenimine derivatives, but the observed stereoselectivity depends on the structure of the substrates.
    Additional Material: 4 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 21 (1983), S. 2777-2785 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymers that contain crown ether moieties at the side chain and are capable of forming rather tough film were synthesized by the polymer reaction of poly(vinyl alcohol) with formyl derivatives of aliphatic crown ethers such as 12-crown-4, 15-crown-5, and 18-crown-6. In the passive transport of alkali metal picrates across the poly(crown ether) membranes the permeation, particularly of alkali metals which tend to form intramolecular sandwich-type complexes with the crown ether rings, was retarded, compared with a poly(vinyl alcohol) membrane. The cation selectivities in the permeation of poly(crown ether) membranes differed significantly from those of poly(vinyl alcohol).
    Additional Material: 4 Ill.
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  • 6
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The catalytic activities of N-decanoyl-L-histidine and its methyl ester and of dipeptide derivatives containing an L-histidine residue toward the stereoselective hydrolysis of enantiomeric substrates have been studied at pH 7.30 (in 0.01M Bis-tris buffer) and 25°C in the presence of poly(ethyleneimine) derivatives. The dipeptide catalyst revealed greatest stereoselectivity in a quaternized poly(ethyleneimine) derivative. A comparison of catalytic effects on both the rate constants and stereoselectivities of N-decanoyl-L-histidine and its methyl ester elucidates the cooperative effects of carboxyl groups in the polymer domains. The structure of the substrates influenced both the rate constants and stereoselectivities in polymer domains.
    Additional Material: 6 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 22 (1984), S. 1697-1699 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Tab.
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  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 151-163 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The rheological behavior of an uncrosslinked polybutadiene on sudden application of finite strain was examined. The shear stress σ, two components of birefringence, and the extinction angle were measured in shear (magnitude of shear γ ≤ 3.5) and tensile stress and the birefringence were measured in uniaxial elongation (elongation ratio λ ≤ 3.8). Measurements were performed at 30°C with a tensile tester equipped with appropriate sample holders. The stress-optical coefficient was 3.01 × 10-9Pa-1. The first and second normal-stress differences v1 and v2 were separately evaluated with the use of stress-optical law. The Lodge - Meissner relation v1 = γσ held good. The ratio v2/v1 was independent of time and varied from about -0.3 to -0.2 with increasing γ in the range of measurements. Each of the stress components was factored into a function of strain and one of time, and the latter was common to all the stress components. Simple formulas were proposed to represent stress components in step deformations.
    Additional Material: 8 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 517-527 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The shear stress σ, two components of birefringence, and extinction angle were measured for a concentrated polystyrene solution in step-shear deformation of magnitude of shear 0.3 ≤ γ ≤ 4.0. The stress-optical coefficient did not depend on either γ or time. The first and the second normal-stress differences v1 and v2 were evaluated with the use of the stress-optical law. Over a certain range of long times, σ could be factored as σ = γh(γ)G(t) and the quantity h(γ) agreed with the prediction of the Doi-Edwards theory based on the de Gennes tube model of entangled polymer chains. At short times the effect of γ on σ/γ was smaller than at long times. The relaxation spectrum became approximately independent of γ at the short-time end of the rubbery plateau region. The ratios v1/σ and v2/v1 were independent of time and were in quantitative agreement with those predicted by the Doi-Edwards theory: v1/σ was equal to γ, v2/v1 was negative, and |v2/v1| decreased with increasing γ.
    Additional Material: 6 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 21 (1983), S. 367-378 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Blends of poly(butylene terephthalate) (PBT) and a copolyester of bisphenol-A with 50% terephthalate-50% isophthalate (PAr), before and after transesterification, have been studied by thermal and dynamic mechanical tests to determine crystallinity and phase behavior. Blends without transesterification, as prepared by solution precipitation, show a single Tg, indicating amorphous miscibility of PBT and PAr. A melting-point depression for PBT crystals is not observed; this means that PBT crystallizes excluding PAr and the entropy of melting is small. The highest fractional crystallinity for PBT is obtained at 20-35% of PAr. Transesterified blends were obtained by holding the physical blends at 250°C for up to 16 h. The transesterified systems show higher Tg's than the corresponding physical blends and also show a marked melting-point depression and lesser PBT crystallinity at the corresponding increased PAr content.
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