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  • 1
    Electronic Resource
    Electronic Resource
    The Theory of Absolute Reaction Rates Applied to the Study of Polarographic Waves. (1949)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 53 (1949), S. 1453-1464 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j150474a013
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  • 2
    Electronic Resource
    Electronic Resource
    Mechanism of emulsion polymerization of vinylidene chloride. I (1961)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 5 (1961), S. 23-30 
    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: The rate of emulsion polymerization of vinylidene chloride has been measured as a function of catalyst and surfactant concentration in the system consisting of vinylidene chloride, water, ammonium persulfate, sodium metabisulfite, and sodium lauryl sulfate. The polymerization may be divided into three rather well-demarcated stages. In the first, a normal emulsion polymerization occurs at a rate which depends on the 0.6-power of the catalyst concentration and the 0.6-power of the surfactant concentration. In the second stage, the rate drops to less than half that of Stage I. The percentage conversion at which Stage II begins increases with increasing surfactant concentration. Stage II is absent at very high surfactant concentrations (10 g./100 g. monomer). In the third stage, the rate increases and may exceed the rate of Stage I; it depends on the first power of the catalyst concentration and is independent of surfactant concentration. Addition of catalyst at the end of the first stage does not affect the rate of Stage II but increases the rate of Stage III. These results are discussed in relation to the theories of Harkins, Smith, and Ewart.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1961.070051304
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  • 3
    Electronic Resource
    Electronic Resource
    Mechanism of emulsion polymerization of vinylidene chloride. II. Effect of coalescence of polymer particles on kinetics (1961)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 5 (1961), S. 31-38 
    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 seeking an explanation for the unusual kinetics observed in the persulfate-catalyzed emulsion polymerization of vinylidene chloride, the role of particle coalescence has been examined. A theory has been proposed and the predicted results have been compared with experiment. Development of the theory assumes that after excess surfactant (sodium lauryl sulfate) has been removed from the solution by adsorption on the surface of growing polymer particles, coalescence commences as a second-order process with an invariant specific rate constant, and that the rate of polymerization per particle increases linearly with particle volume (it is assumed that more than one growing chain can exist in a particle). The equations derived involve two adjustable parameters: B, a measure of the coalescence rate which is fixed from best fit of one experimental resin, and A, a function of the catalyst concentration. The equations predict a minumum in the conversion rate at some time after the coalescence starts. Data for the third stage of the per-sulfact-catalyzed polymerization of vinylidene cholride can be explained by this theory. It is shown that particle coalescence alone cannot completely explain all of the observations which have been made on this system, however; in particular, the extent of slowdown in Stage II greatly exceeds that predicted by theory.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1961.070051305
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  • 4
    Electronic Resource
    Electronic Resource
    Fine structure of regenerated cellulose films as revealed by dye accessibilityPaper presented at the 49th Annual Meeting of the Technical Association of the Pulp and Paper Industry, New York, February 23-27, 1964. (1965)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 2591-2606 
    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: We have demonstrated the utility of dyeing techniques, using Solophenyl Fast Blue Green BL, to characterize a variety of regenerated cellulosic films. Measurement of the optical density ratio and the rate and magnitude of dye uptake show that differences in structure exist in regenerated cellulose films processed under different conditions. These differences are attributed to differences in lateral order and orientation of cellulose chains and are believed similar to the so-called skin and core observed in rayon fibers. These differences have been found related reproducibly to differences in regenerating and processing conditions. Diffusion of dye into a film is very rapid initially, slowing later to an almost constant rate, depending on the dye concentration in solution and on the type of film. A modified diffusion equation of the form In C/C0 - (1 - C/C0) = Dγ2-tC0/Cf has been found adequate to express the non-steady state of the observed absorption process, where C0 is the initial dye concentration of the test solution, C is the instantaneous dye concentration at time t, Cf is the dye concentration in the film, γ2 is the area of film per unit volume of dye solution, and D is the diffusion coefficient. Thus, a mathematical basis is provided for structural differentiation in cellulosic films processed in various ways. Plate-cast viscose films appear to have a dense surface (skin) exposed to the regenerating bath and a porous surface (core) on the side touching the plate, whereas machine-cast viscose films have a dense surface on both sides.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1965.070090720
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  • 5
    Electronic Resource
    Electronic Resource
    Mechanism of emulsion polymerization of vinylidene chloride. III. Effects of stirring rate on kinetics (1961)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 5 (1961), S. 39-47 
    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: The effect of stirring speed on the rate of the persulfate-catalyzed polymerization of vinylidene chloride has been determined. It was found that the first-stage rate decreases with increasing stirring speed, that the second-stage rate increases with increasing stirring speed, and that the rate of the third stage is independent of stirring speed. These results, as well as those of an earlier paper, may be explained in the following manner. The second stage slow-down results from monomer starvation, caused by slow diffusion from coalesced droplets. Recovery is caused by transfer of monomer at the time of collision between a polymer particle and a monomer droplet. These collisions are allowed when the repulsive forces between monomer droplet and polymer particle are reduced because of surfactant deficiency.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1961.070051306
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  • 6
    Electronic Resource
    Electronic Resource
    The effect of softeners on the elastic modulus of regenerated cellulose sheet (1961)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 5 (1961), S. 655-662 
    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: The dynamic elastic modulus of cellophanes has been measured by use of the resonant frequency of a 2 × 60-mm. strip of film in longitudinal vibration. The niodulus was computed from the resonant frequency length of specinieii, and the cross-sectional area determined from its resonant frequency in transverse vibration. The apparatus is described briefly. Unsoftened film and glycerol-softened films containing 7.3, 13.7, and 21.3% glycerol prepared from the same roll of never-dried regenerated cellulose were conditioned a t 75°F. and 15, 35, and 81% R. H., and the elastic moduli were measured in both directions. Moisture and softerier contents were determined. The reciprocals of the geometric means of the moduli in the machine and transverse directions were plotted as a function of the volume of film containing 1 g. of cellulose. The displacement of the curve obtained for each softened film from the curve for the unsoftened film measures the effect of the softener, since the curves would coincide if the effect of softener were from swelling only. This permits construction of an empirical equation for the modulus of these glycerol-softened films as a function of moisture and softener content. It was found further that the logarithms of the corrected compliance (1/EV2/2c), where E is the geometric mean modulus and Vc is the volunie of film containing 1 g. of cellulose, gave a straight line when plotted as a function of the number of moles of water plus twice the number of glycerol present in 100 g. of cellulose. This indicates that the effect of a mole of glycerol in breaking up the hydrogen-bonded structure of the cellulose is twice as great as that of a mole of water. These results have been compared with similar results obtained on films containing ethylene carbonate and ethylenediamine. With the exception of ethylenediamine-treated films studied a t high humidities, these fdms gave points falling approvimately on the corrected compliance curve obtained for the glycerol-softened and unsoftened films. For these films, however, the simple sums of moles of water plus moles of ethylene carbonate or ethylenediamine monohydrate present in 100 g. of cellulose were used rather than the weighted sum used for the glycerolsoftened films.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1961.070051807
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  • 7
    Electronic Resource
    Electronic Resource
    Interaction of cellulose with small molecules. Glycerol and ethylene carbonateThis work was presented at the 137th National Meeting of the American Chemical Society held at Cleveland in April 1960. (1960)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 3 (1960), S. 331-337 
    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: The equilibrium moisture content of films softened with hygroscopic glycerol or nonhygroscopic ethylene carbonate was determined as a function of softener concentration at 15, 35, 65, 81, and 93% R.H. and compared to the hygroscopicity of unsoftened film and of the pure softeners at the same concentrations. The difference in water content assumed to be caused by interaction between softener and cellulose was calculated in moles of water per mole of softener and per mole of cellulose. A quantitative measure of softener-cellulose interaction at low and high relative humidities is thus obtained. Ethylene carbonate shows a negative interaction and seems to function only as an inert cushion between cellulose chains, while glycerol interacts with cellulose. This interaction increases with decreasing moisture content (at lower relative humidities) and with increased softener concentration. The softener-cellulose interaction is a necessary condition for proper softening.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1960.070030910
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  • 8
    Electronic Resource
    Electronic Resource
    Viscoelastic properties of regenerated cellulose sheet (1961)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 5 (1961), S. 647-654 
    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: The viscoelastic properties of regenerated cellulose containing several different softeners or water only were investigated. Measurements of creep and Young's modulus were made on the Instron tensile tester, and the creep curves were fitted to a mechanical model consisting of Voigt and Maxwell elements of springs and dashpots in series. The elastic and viscous parameters were determined for the various softened films and compared with each other and with measurements of Young's modulus. It was found that the elastic modulus is a function of the effective molar concentration of the softener in the film which is related to its ability to break hydrogen bonds. The inelastic deformation was found to be a linear function of the heat of vaporization of softener (including water) in the film which is related to hydrogen-bonding energy. Thus, inelastic deformation requires breaking of interchain hydrogen bonds in contrast to pure elastic deformation which involves stretching of hydrogen bonds. A relationship of the Voigt unit and of the Maxwell unit on the composition of the cellulose-softener system and on cellulose-softener interaction has been demonstrated.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1961.070051806
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  • 9
    Electronic Resource
    Electronic Resource
    Relationship between dynamic modulus of thin films and stiffness, as determined by the Handle-O-Meter (1963)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 7 (1963), S. 817-832 
    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 series of thirteen polyethylene and ten polypropylene packaging films was studied by both the Handle-O-Meter and the dynamic tensile modulus apparatus, to discover how the stiffness of polyolefin films determined with the Handle-O-Meter depended on the modulus of the material and the thickness of the film. The polyethylene films included low-, medium-, and high-density resins and ranged in thickness from 0.7 to 4 mils. The moduli of these films ranged from 2.5 X 109 to 18 X 109 dynes/cm.2 The polypropylene films were made from several types of resins with moduli varying from 73 x 109 to 54 X 109, and the thicknesses of these films ranged from 0.5 to 4 mils. When the logarithm of the ratio of stiffness to modulus was plotted as a function of the logarithm of the thickness of the film, as determined from unit weights and densities, a straight line was obtained with a slope of 2.5. This means that over a wide range of gauge and modulus the Handle-O-Meter stiffness of these materials, S (in grams), is related to the modulus, E (in dynes per square centimeter), and the thickness, t (in mils), by the equation S = 1.41 X 10-9Et2.5. This result, which shows that the Handle-O-Meter stiffness of polyolefin films may be represented as a function of the thickness and the modulus as given by the dynamic tensile modulus apparatus, may be used to calculate a modulus value from any single Handle-O-Meter stiffness value or, alternatively, to reduce Handle-O-Meter stiffness measurements to a standard thickness. Conversely, this relationship may be used to predict the Handle-O-Meter stiffness of a film made from a polymer whose modulus is known.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1963.070070303
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  • 10
    Electronic Resource
    Electronic Resource
    Melt viscosity of polyethylenes (1960)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 3 (1960), S. 77-83 
    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: The melt viscosity of fractionated and unfractionated polyethylenes at low shear rates have been measured in the temperature range 140-280°C. The melt index is not an adequate measure of melt viscosity determined at low shear rate. From melt viscosity and intrinsic viscosity determinations on fractions an estimate of the degree of long-chain branching can be made. From viscosity measurements at several temperatures between 140 and 280°C. values of the apparent activation energy for fractionated and unfractionated polyethylenes were obtained. The activation energy increases from 8 to 13 kcal. as the weight-average molecular weight increases about 20,000 to about 200,000.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1960.070030711
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