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  • 1
    Electronic Resource
    Electronic Resource
    Theory of rolling plastics. I. Calculation of roll pressurePublished by permission of the Chief Scientific Officer, Ministry of Supply, England. (1946)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 1 (1946), S. 529-534 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An elementary theory is given for the rolling of polymeric materials, for the case in which the deformation is largely an irreversible flow of the viscous type. The theory treats the rolling process as the homogeneous deformation of volume elements over the arc of contact and neglects frictional forces that may exist at the roll surface. A numerical example is given of the calculation of roll pressure, which agrees with available data to a factor of two or better. A more complete test will require parallel measurements of viscosity and roll pressure on the same material.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1946.120010608
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  • 2
    Electronic Resource
    Electronic Resource
    Theory of rolling plastics. II. Thermal effectsPublished by permission of the Chief Scientific Officer, Ministry of Supply, England. (1946)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 1 (1946), S. 535-539 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In the rolling of Plastic sheet the viscous work gives rise to heating of the plastic sheet. The maximum temperature reached in the interior of the sheet during shearing is of the interest, both in the theoretical calculation of roll pressure, and from the point of view of possible thermal decomposition effects. A calculation is given for a simple, some-what artificial, model, which leads to an upper value for this maximum temperature if a measurement of the average temperature of the emergent sheet is given. The model taken is that of an infinite sheet, of thickness 2δ, in which heat is continuously liberated at the rate of 4ηφ2 cal. cc. -1 sec. -1, where φ is the relevant value of the rate of compression (assumed constant across the sheet). The curve giving the temperature distribution across the sheet is calculated numerically for two cases; it is relatively flat, as would be expected on physical grounds, since the viscosity, η, decreases as the temperature rises. It is concluded that these thermal effects may be neglected in the calculation of roll pressure in Part 1.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1946.120010609
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  • 3
    Electronic Resource
    Electronic Resource
    Density of cellulose fibers. III. Density and refractivity of natural fibers and rayonCommunication No. 29 from the Laboratory for Cellulose Research. (1946)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 1 (1946), S. 162-171 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A micromethod is described for density determinations of artificial cellulose fibers by the floating method, in carbon tetrachloride in a dry and air-free atmosphere, permitting an accuracy of one part per thousand. The density is derived from the temperature at which the samples neither sink nor float. This temperature varies, with the kind of fiber, between 45° and 65°C. Measurements of the refractive power were carried out simultaneously. The refractivity calculated according to Gladstone and Dale yields slightly lower figures than those found for model fibers in the preceding communication (Part II). The average difference amounts to seven parts per thousand and is ascribed to a systematic error in the density determinations, due to a slight absorption of carbon tetrachloride by the fibers at elevated temperatures. This explanation is supported by experiments. The density of native ramie, of contracted and reoriented ramie, and of several series of rayon fibers spun with increasing stretch, is given. The conclusion is reached that the density is a measure of the percentage of crystalline substances in the fiber and it is shown that there is a correlation between density and sorptive capacity toward water vapor. The percentage of crystalline matter is estimated to be 55-60% in native ramie and 20-25% in rayon.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1946.120010303
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  • 4
    Electronic Resource
    Electronic Resource
    Comparison of ultraviolet absorption and chlorine analysis methods for composition of butadiene-p-chlorostyrene copolymersThis work was carried out under the sponsorship of the Office of Rubber Reserve, Reconstruction Finance Corporation, in connection with the Government Synthetic Rubber Program. (1946)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 1 (1946), S. 247-248 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A comparison has been made of the ultraviolet spectrophotometric and chlorine analysis methods for the composition of copolymers of butadiene and p-chlorostyrene. The results of the two methods are in good agreement.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1946.120010404
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  • 5
    Electronic Resource
    Electronic Resource
    Determination of persulfate in emulsion polymerization laticesThis investigation was carried out under the sponsorship of the Office of Rubber Reserve, Reconstruction Finance Corporation, in connection with the Government Synthetic Rubber Program. (1946)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 1 (1946), S. 340-352 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In the emulsion polymerization of butadiene, styrene, or both, potassium persulfate is often used as the catalyst. A convenient concentration of potassium persulfate in the aqueous layer of the charge is 0.10-0.2%; the method of analysis should therefore be suitable for very small persulfate concentrations. Three methods have been investigated. In the volumetric method the persulfate is allowed to react in an acid medium with an excess of standard ferrous iron, the excess being back-titrated after a given period of time with standard ceric cerium solution. The recommended procedure was found accurate and precise within 0.5%, even at such small concentrations as 5 mg. of potassium persulfate per 100 ml. When latex is analyzed by this method, the polymer is first removed by coagulation with sulfuric acid and the persulfate determined in the filtrate. In order to obtain reliable results the reaction between the persulfate and ferrous iron in the filtrate must be carried out in the absence of oxygen, although this is not necessary in solutions of pure persulfate. The interference by oxygen is attributed to substances of peroxidic character in the fatty acid soaps used as emulsifiers in the emulsion polymerization. The colorimetric method (“Becco” method) is based upon the oxidation of the leuco base of commercial wool green BSMA to a green dye by the persulfate and (colorimetric) measurement of the dye formed. The various factors affecting the accuracy and precision of this method have been investigated and a procedure is given for the analysis of latex. For several reasons, the volumetric and polarographic methods are superior to the colorimetric method. Persulfate in a latex can be determined accurately by polarographic analysis of the latex filtrate after removal of the polymer with sulfuric acid. The polarographic determination can be carried out, in the presence of oxygen, with simple equipment. The method is rapid and precise.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1946.120010502
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  • 6
    Electronic Resource
    Electronic Resource
    Deformation mechanism of cellulose gels. II. Course of crystallite orientation compared to that required by Kratky's theoryCommunication No. 32 from the Laboratory for Cellulose Research, Utrecht. (1946)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 1 (1946), S. 393-406 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The paper offers a verification by x-ray experiments of Kratky's theory of affined transformation (affine Raumverzerrung), aiming at an explanation of the mechanism of deformation of swollen cellulose gels upon stretching. Isotropic model filaments of various degrees of swelling were stretched to various extents and x-ray photographs were then taken. Following Kratky, the intensity distribution along the sickles of two paratropic planes of the ribbon-shaped crystallites, the lamellar plane, A0 and the A3 plane (perpendicular to the latter) were measured and the average orientation, expressed in terms of the orientation factor, fx, was calculated. The superposition of the (021) interference on that of the A3 sickle, which had been neglected by Kratky, was accounted for. The experimental results are in conformity with certain characteristic features of the theory; (a) the orientation of the A0 planes advances more rapidly than that of the A3 planes; (b) regardless of the initial degree of swelling of the isotropic filament, the average orientation is actually a univocal function of the elongation, va. On the other hand, the rate of orientation appears to be much greater than that required by theory; the average orientation, expressed in terms of the orientation factor, increases almost twice as rapidly. It is shown, moreover, that, apart from low degrees of orientation, Kratky's theory fails to explain the velocity function of the relative rotation of the crystallites, as derived from the experimental data according to a procedure proposed by Kratky. It is concluded that further work is required to elucidate the mechanism of deformation.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1946.120010507
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  • 7
    Electronic Resource
    Electronic Resource
    Density of cellulose fibers. I. Introduction and experiments on the penetration of liquids into dry celluloseCommunication No. 27 from the Laboratory for Cellulose Research. (1946)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 1 (1946), S. 149-155 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In this paper it is emphasized that density is a typically macroscopic concept which cannot be transferred to small particles or bodies with small pores. This fact has not been duly accounted for in earlier work on the density of cellulose fibers. The usual interpretation of density determinations in various media is criticized and the point of view that cellulose fibers should be considered as porous bodies is dropped. The pore system occurring in native fibers is coarse enough not to interfere with density determinations in indifferent organic liquids.It is shown experimentally that even substances like water and glycerol penetrate very slowly into dry cellulose and that indifferent organic liquids do not penetrate at all. In the experiments with water vapor a new phenomenon, the heterogeneous course of absorption, is observed, giving rise to sharp microscopically visible boundary lines between the wet and the dry portion of the fiber.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1946.120010301
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  • 8
    Electronic Resource
    Electronic Resource
    Density of cellulose fibers. II. Density and refractivity of model filamentsCommunication No. 28 from the Laboratory for Cellulose Research. (1946)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 1 (1946), S. 156-161 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Accurate determinations of the density and refractive power of various types of model filaments prepared from viscose in the bone-dry state were made. The molecular refraction, according to the formula of Gladstone and Dale, was calculated and shown to correspond within three parts per thousand with the refraction calculated from atomic refractions. It is concluded that the liquid used for the density determinations (mixtures of carbon tetrachloride and nitrobenzene) does not penetrate into the fiber substance. The technique of the experiments is described in detail. The immersion liquids used in the optical measurements were standardized mixtures of butyl stearate and tricresyl phosphate; contamination with moisture during the measurements was definitely excluded.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1946.120010302
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  • 9
    Electronic Resource
    Electronic Resource
    Advances in colloid science. Volume II. Scientific progress in the field of rubber and synthetic elastomers. Edited by H. Mark and G. S. Whitby. Interscience, New York, 1946. xl and 433 pp. Author and subject indexes. Price $7.00 (1946)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 1 (1946), S. 582-582 
    Details
    ISSN: 0022-3832
    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/pol.1946.120010613
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  • 10
    Electronic Resource
    Electronic Resource
    True cholinesterases with pronounced resistance to eserine (1946)
    Philadelphia : Wiley-Blackwell
    Journal of Cellular and Comparative Physiology 27 (1946), S. 69-85 
    Details
    ISSN: 0095-9898
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1030270202
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