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  • 1
    Electronic Resource
    Electronic Resource
    Analysis of fluorinated polymers: Several approaches by wide-line nuclear magnetic resonance (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 2815-2819 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Two different ways of analyzing the composition of insoluble, partly hydrogenated, partly fluorinated copolymers by NMR are described. The first relies on a quantitative comparison of 1H and 19F free induction decays, as observed in the solid state, with those of reference samples. The second relies on medium resolution spectra which can be achieved, thanks to the large scale of 19F chemical shifts, on softening of the samples at high temperature. A special probe working up to 400°C was built for this purpose. The two methods are in good agreement in the case of vinylidene fluoride (VF2)/tetrafluoroethylene (VF4) copolymers, leading to a determination of the rectivity ratios; the special usefulness of the second method is illustrated by the identification of a third comonomer in VF2/VF4 terpolymers.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021901113
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  • 2
    Electronic Resource
    Electronic Resource
    Factors affecting the promoted aggregation and coalescence of synthetic rubber particles (1964)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 8 (1964), S. 2049-2065 
    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: Small particles (ca. 700 A.) in an SB-R latex can be agglomerated (aggregation and coalescence) to the large size and heterogeneous distribution required for fluid high solids latex. This agglomeration is promoted by high molecular weight materials such as polyvinyl methyl ether (PVM). The mechanism of this agglomeration has been investigated. The effects of controlled variations in the amounts of PVM, electrolyte, soap and latex solids content were determined using statistically designed experiments. The agglomeration was found to differ from Smoluchowski kinetics in that it could best be described by the relationship: (1/n) = (1/n0) + at - bt2 where n = particle number, t = time and a and b are constants. The agglomeration rates were about 1011 to 1012 times slower than the theoretical Smoluchowski rapid coagulation rate. Increases in PVM, soap, and latex solids increased the agglomeration rate. The agglomerations were self-limiting and reached equilibria the level of which increased with increases in PVM and decreased with increases in soap. Regression equations relating the effects of the controlled variables on the agglomeration rate and the equilibria states are derived and presented graphically. The particle size distribution of the final latex was significantly correlated, with that expected from theoretical collision theory.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1964.070080509
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  • 3
    Electronic Resource
    Electronic Resource
    Surface treatment of an epoxy resin by CO2 laser irradiation (1996)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 238 (1996), S. 177-189 
    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: Der Einfluß von CO2-Laserstrahlung auf die Oberflächeneigenschaften eines Epoxid-Laminierharzes (wärmebeständig bis 120°C) für kohlefaserverstärkte Kunststoffe (CFK) wird untersucht. Infrarot- und XPS-Spektroskopie zeigen, daß die Hydroxygruppen des Harzes unter Bildung von Doppelbindungen eliminiert werden. In Kohlendioxidatmosphäre werden tiefer liegende Teile des Harzes modifiziert als bei der Behandlung in Luft. Eine Steigerung der Reproduzierbarkeit der Klebfestigkeit des verwendeten CFK auf Basis des untersuchten Harzes ist nur bei gleichzeitiger Verringerung der Klebfestigkeit selbst möglich. Beim Einsatz eines heißhärtenden Klebstoffes kann kein Einfluß der Laserbehandlung auf die Klebfestigkeit festgestellt werden.
    Notes: The influence of CO2 laser radiation on the surface properties of a lamination resin (temperature resistant up to 120°C) which is used for carbon fibre-reinforced plastics (CFRP) is examined. It is shown by XPS and infrared spectroscopy that the hydroxy groups of the resin are eliminated by the laser radiation. Using a carbon dioxide atmosphere, also deeper parts of the resin are influenced compared to the treatment in air. The reproducibility of the bond strength is higher for the laser-treated samples than for untreated samples if a room temperature-curing adhesive is used, but the bond strength itself is lower. Laser treatment shows no influence at all if a hot-curing adhesive is used.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1996.052380115
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  • 4
    Electronic Resource
    Electronic Resource
    The liquid-crystalline properties of selected cellulose derivatives (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 26 (1988), S. 1101-1110 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The liquid-crystalline properties of three cellulose esters, phenylacetoxy cellulose (PAC), 4-methoxyphenylacetoxy cellulose (4MPAC), and p-tolylacetoxy cellulose (TAC) and two cellulose silyl ethers, trimethyl silyl cellulose (TMSC) and t-butyldimethylsilyl cellulose (TBDMSC), are reported.Hot-stage polarized light microscopy provided evidence regarding the formation of thermotropic mesophases in the PAC, 4MPAC, TAC, and TMSC in bulk form upon heating. The concomitant DSC data showed further evidence of the thermotropic nature of these materials.PAC, 4MPAC, TAC, and TMSC formed lyotropic mesophases at 44, 48, 50, and 27 wt%, respectively in CH2Cl2. The presence of fingerprint patterns in wholly anisotropic solutions in conjunction with optical rotation measurements confirmed the cholesteric nature of these liquid crystalline solutions. TBDMSC formed neither a lyotropic nor a thermotropic liquid-crystalline phase due to the low degree of substitution (DS 0.68) of this derivative. The hydroxyl substituents of PAC, 4MPAC, TAC, and TMSC may be readily removed under mild conditions to regenerate cellulose.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1988.090260514
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  • 5
    Electronic Resource
    Electronic Resource
    Sorption and transport properties of MY720/DDS epoxy reacted with blocking reagents (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 26 (1988), S. 1261-1270 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Thin films of the epoxy formed by the reaction of tetraglycidyl 4,4'-diamino-diphenylmethane and 4,4'-diaminodiphenyl sulfone (73:27 w/w) were reacted with acrylonitrile (ACN) and isocyanates as blocking reagents for hydroxyl, amine, and epoxy groups. The water uptake at 30, 45, 55, and 70°C of the epoxy resin was monitored gravimetrically. At each temperature the epoxy exhibited case I or Fickian behavior. The diffusion coefficient D increased from 30 to 55°C, but decreased at 70°C because of the reaction of water with residual oxirane groups. Diffusion of ACN is accompanied by both reaction and polymerization, so equilibrium could not be reached. Sorption of the isocyanates essentially follows case I or Fickian behavior. Equilibrium moisture absorptions showed a correspondence between the reduction of moisture absorption and the number of blocked functional groups, irrespective of the nature of the blocking groups. Moisture absorption reductions as high as 68% were obtained. Moisture diffusion of the films after blocking with the various reactants exhibits case I or Fickian behavior. At 30°C, D values are significantly higher for reacted films. At 70°C, the value of D is unchanged as compared with the 30°C value for films reacted with ACN, but D values are significantly lower for films reacted with isocyanate blocking reagents as compared with the epoxy resin.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1988.090260610
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  • 6
    Electronic Resource
    Electronic Resource
    Effects of ionizing radiation on epoxy, graphite fiber and epoxy/graphite fiber composites. Part I: Surface energy changes (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 26 (1988), S. 245-255 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Surface energy changes of an epoxy based on tetraglycidyl diaminodiphenyl methane (TGDDM)/diaminodiphenyl sulfone (DDS), T-300 graphite fiber, and T-300/5208 (graphite fiber/epoxy) composites have been investigated after irradiation with 0.5 MeV electrons. The surface energy of TGDDM-DDS epoxy increases monotonically with radiation doses up to 1,000 Mrad mainly due to increased concentration of polar groups. IR and ESCA spectral evidence indicates that carbonyl groups are formed, probably from the tertiary hydrogen at the carbon where the —OH group is attached in the cured epoxy. The polarity of the graphite fiber and the graphite fiber/epoxy interface also increases with radiation dose. These results and the roles of oxygen are discussed in connection with mechanical properties of epoxy/graphite fiber composites exposed to ionizing radiation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1988.090260203
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  • 7
    Electronic Resource
    Electronic Resource
    Effect of ionizing radiation on the dynamic mechanical properties of an epoxy and a graphite fiber/epoxy composite (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 27 (1989), S. 1185-1185 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1989.090270518
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  • 8
    Electronic Resource
    Electronic Resource
    Solid-state cpmas 13C-NMR studies of the reaction of an epoxy resin with masked isocyanates (1990)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 28 (1990), S. 293-302 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It has been shown that incorporation of masked isocyanates in the MY720/DDS epoxy significantly reduces the equilibrium moisture absorption by blocking of residual functional groups ( oxirane group) by the isocyanates released in the deblocking reaction of the masked isocyanates. We have now used high resolution 13C-CP/MAS NMR to follow the reactions in the solid state and to identify intermediates and by-products. The deblocking reaction of the masked isocyanates also releases the corresponding alcohol, part of which may evaporate during the curing reaction. The resolution in the solid-state spectra is good enough to identify all the reactants and the intermediates involved in the curing reaction. Difference spectra are used to emphasize changes between systems that differ in treatment or composition.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1990.090280304
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  • 9
    Electronic Resource
    Electronic Resource
    Free radical synthesis of α,ω-primary amino functionalized polyisoprene through the functional thermal inferter [bis(N-(2-phthalimidoethyl)piperazine)]thiuram disulfide (1994)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 195 (1994), S. 243-251 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The primary amino functional iniferter [bis(N(2-phthalimidoethyl)piperazine)]thiuram disulfide (PEPTD) was synthesied and characterized. Thermal polymerization of isoprene in the presence of the initiator afforded α,ω-functionalized polyisoprene with primary amino end-groups after cleavage of the phthalimido group with butylamine. The kinetics of polymerization of isoprene using this iniferter was studied at 80, 85, 90 and 100°C. Interestingly, isoprene showed a complex kinetic behavior. The different parameters, related to initiation, chain transfer and primary radical termination reactions, as well as the constants for thermal decomposition of the initiator, were determined. From the Arrhenius plot, the activation energy of the overall decomposition constant of PEPTD (2 f kd) was calculated to be 110 kJ/mol. The functionality of the telechelics was examined by GPC.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1994.021950122
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  • 10
    Electronic Resource
    Electronic Resource
    Electron paramagnetic resonance investigation of the nature of the propagating species in methyl methacrylate polymerization (1994)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 195 (1994), S. 3159-3172 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The electron paramagnetic resonance (EPR) spectrum of methyl methacrylate polymerizing in a range of systems is simulated using a consistent set of parameters for two rotamers of a single free radical. The 9-line spectrum observed in bulk and emulsion polymerization was fitted by a superposition of two spectra corresponding to two rotamers of a long-chain species (each a somewhat hindered, non-rotating macroradical), having anisotropic methylene proton hyperfine couplings which can be treated as isotropic to a good approximation. The 13-line spectrum observed at low conversion with very high radical flux was simulated as a superposition of the spectra of two very similar rotamers, the EPR spectra of which are indistinguishable; either rotamer is part of a very short chain (primarily an initiator fragment which has propagated once) undergoing free rotation in a low-viscosity medium. Thus the EPR spectra can be explained without having to invoke earlier suggestions that there are two types of free radicals (“trapped” and “untrapped”) in these systems, corresponding to the 9-line and 13-line spectra. The existence of an enormous proportion of very short free radicals under conditions of high radical flux is supported by quantitative calculations of the radical chain-length distribution. It is suggested that the two rotamers have significantly different propagation rate coefficients because of differences in the hindered rotations in their transition states.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1994.021950914
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