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1

Digitale Medien

Sur le mécanisme du gonflement des hauts polymères cristallins par les solvants (1967)

Descamps-Carlier, J. ; Homès, G. A. ; Point, J. J.

New York : Wiley-Blackwell

Die Makromolekulare Chemie 109 (1967), S. 1-8

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ISSN: 0025-116X

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Physik

Beschreibung / Inhaltsverzeichnis: Bei Raumtemperatur zu Filmen geformte und dann bei 110°C getemperte Polyäthylenproben wurden bei 85°C in Biphenyl gequollen und dann auf Raumtemp. abgeschreckt.Wie Klein- und Weitwinkel-Röntgenstreuungen zeigen, kristallisiert das Bisphenyl in flachen, etwa 10 Å dicken Kristallen zwischen den Polyäthylen-Einkristallen. Die gequollenen Proben sind fibrillär; sie lassen sich, wie die Elektronenbeugung zeigt, in Einkristalle aufspalten. Die Quellung beeinflußt die Textur der ursprünglichen Polyäthylenprobe nicht, welche eine b-Achsen-Orientierung hat. Die Orientierung der Bisphenylkristalle hängt nur von der Polyäthylentextur ab; Bisphenyl hat hier ebenfalls b-Achsen-Orientierung, die parallel zur Orientierung des Polyäthylens ist.

Notizen: Specimens of polyethylene laminated at room temperature and annealed at 110°C were swelled at 85°C by biphenyl and then quickly allowed to cool to room temperature.X-ray diffraction studies at large and low angles revealed that during the cooling process, biphenyl crystallizes into flat crystals of about 10 Å thickness, located between the polyethylene single crystals. The swelled specimens are friable. It is possible to desaggregate them into single crystals as shown by electron diffraction. Swelling does not affect the texture of the initial polyethylene specimens which is that of a b̄ axis fibre. Further more during the cooling process the orientation taken by the biphenyl crystals depends only on the polyethylene texture. The texture of biphenyl is that of a b̄ axis fibre parallel to the polyethylene fibre.

Zusätzliches Material: 6 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/macp.1967.021090101

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2

Digitale Medien

Precision viscometry of polymer solutions (1955)

Kooy, J. ; Hermans, J. J.

Hoboken, NJ : Wiley-Blackwell

Journal of Polymer Science 16 (1955), S. 417-427

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ISSN: 0022-3832

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Physik

Notizen: The article describes a method for measuring times of efflux in a capillary viscometer with an accuracy of 0.003 sec. A film is taken of the moving meniscus together with a synchronous clock. The temperature of the thermostat bath is controlled to within 0.001°C. by means of a Wheatstone bridge which contains temperature dependent resistances. Experimental results obtained with a polystyrene sample in toluene show no systematic deviation from linearity in the ηsp/c vs. c curve between 2 × 10-3 and 3 × 10-5 g./ml. The same curve for a sample of polymethacrylate in water shows a sharp maximum at about 10-4 g./ml.

Zusätzliches Material: 4 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/pol.1955.120168228

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3

Digitale Medien

Antiplasticization. III. Characteristics and properties of antiplasticizable polymersPaper presented at the 152nd National Meeting of the American Chemical Society, New York, September 1966.Prod. No. 1451 (1967)

Jackson, W. J. ; Caldwell, J. R.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Applied Polymer Science 11 (1967), S. 227-244

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ISSN: 0021-8995

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: Antiplasticization is applicable to polymers which contain rigid, polar groups and stiff chains, such as many bisphenol polycarbonates and polyesters, 2,2,4,4-tetramethyl-1,3-cyclobutanediol polycarbonates and polyesters, cellulose triacetate, and a commercial poly(sulfone ether). The stiffness, hardness, and tensile strength of these polymers are increased by antiplasticizers, and the elongation, impact strength, and heat-distortion temperature are decreased. The stiffness of antiplasticized polymers can be further increased by crystallization. A clear, hard, stiff, tough, self-extinguishing molding plastic with good electrical properties and improved resistance to stress cracking is obtained by antiplasticizing bisphenol A polycarbonate with 20% Aroclor 5460.

Zusätzliches Material: 9 Tab.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/app.1967.070110206

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4

Digitale Medien

Investigation of conditions of spherulite formation in mixtures of crystalline and amorphous polymersProd. No. 1454 (1967)

Bartoň, J. ; Rak, J.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Applied Polymer Science 11 (1967), S. 499-514

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ISSN: 0021-8995

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: The supermolecular structure of mixtures of crystalline polymers (low pressure and high pressure polyethylene, isotactic polypropylene) with an amorphous polymer (atactic polypropylene) from the point of view of the influence of the amorphous component on the morphology of the crystalline component has been investigated. The criterion of changes in the morphological state of larger supermolecular formations was the microscopic image of the samples obtained with an optical microscope, both between crossed nicols and in phase contrast. It has been established that the formation of typical spherulites depends on the amount of admixture of the amorphous polymer and also on the treatment of the samples. Upon crystallization in presence of a small amount of solvent (p-xylene), formation of typical spherulites of the crystalline component of the mixture can be observed while the same mixture in case of evaporation of the solvent presents a granulated refractive structure without typical spherulites, regardless of the rate of cooling. The probable role of the solvent is to facilitate mutual segregation of the microphases of both polymers in consequence of decrease in viscosity of the mixture. It has been further shown that even after briefly heating the mixture to a temperature of 220°C., before crystallization, spherulites do not form; on the contrary, spherulites originally present disappear and a structure consisting of smaller refractive formations of crystalline polymer is obtained. The formation of this structure, emerging after destruction of spherulites, might be attributed to an increase of interpenetration of both polymers and to an increase of the contact surfaces between components of the mixture.

Zusätzliches Material: 9 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/app.1967.070110402

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5

Digitale Medien

Thermal behavior of dimethyl-m-carboranyl-dimethylsiloxane copolymersPaper presented at the American Chemical Society Regional Meeting, Louisville, Kentucky, October 27-29, 1966.Prod. No. 1599 (1967)

Delman, A. D. ; Stein, A. A. ; Kelly, J. J. ; [weitere]

New York, NY [u.a.] : Wiley-Blackwell

Journal of Applied Polymer Science 11 (1967), S. 1979-1990

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ISSN: 0021-8995

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: The manner in which a series of silcarboranylene-siloxane polymers behave in air at elevated temperatures was investigated by thermogravimetric, isothermogravimetric, and differential thermal analyses techniques. Results indicate that methyl pendant groups on the polymers undergo thermal and oxidative degradations at temperatures under 600°C. Final weight losses of the polymers, however, are significantly lower than that shown by dimethylsiloxanes. The reduced volatility is attributed to the inhibition of thermooxidation by the m-carboranylene group in the polymer molecules. This protective influence decreases apparently as the distance between the carborane nucleus and the methyl groups increases.

Zusätzliches Material: 8 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/app.1967.070111014

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6

Digitale Medien

Programmed polymer light-scattering data (1967)

Evans, J. M. ; Huglin, M. B. ; Lindley, J.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Applied Polymer Science 11 (1967), S. 2159-2174

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ISSN: 0021-8995

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: An ALGOL computer program has been devised to manipulate light-scattering data from the Brice-Phoenix photometer. The input consist of experimental values of the galvanometer deflections and filter factors used for each concentration c and angle of measurement θ. These are transformed to the appropriate variables in the fundamental equation including the particle scattering factor, viz: c/Qθ = (W/K*)M̄w-1[1 + (16/3) × π2n12λ〈S2〉 sin2 (θ/2)] + (W/K*)2A2c + (W/K*)3A3c2 in which Qθ is a corrected from of the Rayleigh ratio and (W/K*) is a composite constant term for the instrument and polymer-solvent system. By writing X̄ij for the variable c/Qθ at θi and cj, a function X is found by least squares to fit X̄ij, thus X = l + m sin (θ/2) + ncj + bcj2. The equations arising from minimizing ΣiK=1 ΣjL=1 (Xij - X̄ij)2 are solved by the computer to yield the best-fitting coefficients l, m, n, and b. These can then be related simply to the molecular weight, root-mean-square radius of gyration, second and third virial coefficients, respectively. The final portion of the program is designed to check the fit of these coefficients. It yields a table of the differences between all experimental c/Qθ values and the coressponding ones obtained by inserting the derived l, m, n, and b into the fundamental equation. The procedure has been tested satisfactorily by using a well-standardized sample of polystyrene in toluene at 30°C. and a wavelength of 436 mμ.

Zusätzliches Material: 6 Tab.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/app.1967.070111107

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7

Digitale Medien

Wool-polymer systems: Effect of vinyl polymers on water absorption Prod. No. 1573 (1967)

Leeder, J. D. ; Pratt, A. J. ; Watt, I. C.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Applied Polymer Science 11 (1967), S. 1649-1659

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ISSN: 0021-8995

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: Acrylamide, acrylic acid, and acrylonitrile have been polymerized in situ within wool fibers and the water-absorption properties of the resultant wool-polymer systems compared with those of wool and the polymers measured separately. At high humidities, polyacrylamide and, to a lesser extent, poly(acrylic acid) caused increased water uptakes when expressed as a function of the original weight of wool, due to the hydrophilic nature of these polymers. This increase was less than that expected from the water contents of the wool and polymers measured as separate entities. Chain entanglements in the polymer-keratin network may be responsible for some reduction of water content. The presence of polyacrylonitrile in wool reduced the water content at high humidities to less than that of wool alone, indicating that “volume exclusion” of water by the polymers is also a contributing factor. At low humidities, the water content of the wool-polyacrylamide system is equivalent to the sum of the water contents of wool and polymer taken separately; in the case of poly(acrylic acid) the water content is less than that of wool and polymer considered separately, and this is attributed to ionic bonding. For wool containing polyacrylonitrile there is a reduction in water content at low humidities, indicating interaction between the polymer and polar sorption sites in the wool.

Zusätzliches Material: 4 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/app.1967.070110905

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8

Digitale Medien

The use of porous glass as a column packing for gel permeation chromatographyPart XIII of a series on column fractionation of polymers.Prod. No. 1621 (1967)

Cantow, M. J. R. ; Johnson, J. F.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Applied Polymer Science 11 (1967), S. 1851-1854

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ISSN: 0021-8995

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: Use of porous glass with a broad pore-size distribution as a column packing for gel permeation chromatography has been investigated. The porous glass is readily available, and columns are packed easily and have excellent mechanical stability. Separations of polystyrene over molecular weight ranges of 500-2,000,000 have been obtained. Porous glass thus appears to be a useful packing material for gel permeation chromatography.

Zusätzliches Material: 3 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/app.1967.070111003

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9

Digitale Medien

The effect of molecular weight distribution on the melt flow behavior and the spectrum of relaxation times of polystyrene (1967)

Toelcke, G. A. ; Madonia, K. J. ; Gogos, C. G. ; [weitere]

Stamford, Conn. [u.a.] : Wiley-Blackwell

Polymer Engineering and Science 7 (1967), S. 318-323

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ISSN: 0032-3888

Schlagwort(e): Chemistry ; Chemical Engineering

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Zusätzliches Material: 7 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/pen.760070413

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10

Digitale Medien

Fractionation of polymers on a preparative scale by precipitation chromatography (1967)

Henderson, J. F. ; Hulme, J. M.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Applied Polymer Science 11 (1967), S. 2349-2360

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ISSN: 0021-8995

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: A preparative-scale elution chromatographic column is described which will fractionate 45 g. of polymer in a single operation. The size of the column is kept to manageable dimensions by reducing the temperature differential from 50 to 10°C. along the length of the temperature-gradient section. It appears that this change limits the range of molecular weights that are in this section of the column at any one time which leads to a more uniform distribution of a polymer along the column. The net result is that the ratio of polymer load to cubic capacity of the column as a whole can be increased about tenfold over that for the conventional analytical column. It is shown that the equation derived by Caplan is valid under a variety of conditions and that this equation supports the arguments which lead to a reduced temperature differential in the column.

Zusätzliches Material: 7 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/app.1967.070111122

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