Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1985-1989  (13)
Source
Material
Years
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Sorption and transport of inert gases in PVF2/PMMA blends (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 32 (1986), S. 4793-4814 
    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: Sorption and transport of several inert gases (He, Ar, N2, and CH4) in miscible blends of PMMA and PVF2 are reported as a function of pressure at 35°C. For each gas, the permeabilities are independent of pressure for all blend compositions. Sorption isotherms are linear for rubbery compositions (PVF2-rich) and nonlinear for glassy compositions (PMMA-rich) as expected. In contrast to CO2, these gases do not plasticize any of these materials. The data are analyzed using appropriate models for sorption and transport, and the parameters are correlated in terms of blend composition and molecular characteristics of the gases. Effects of crystallinity are discussed. Sorption behavior is compared with poly(methyl acrylate) and poly(vinyl acetate).
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1986.070320503
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Gas permeation in miscible homopolymer-copolymer blends: II. Tetramethyl bisphenol-A polycarbonate and a styrene/acrylonitrile copolymer (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 34 (1987), S. 1503-1520 
    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: Gas sorption and transport properties for He, H2, O2, N2, Ar, CH4, and CO2 at 35°C near atmospheric pressure have been obtained for miscible blends of tetramethyl bisphenol-A polycarbonate (TMPC) and a random copolymer of styrene with acrylonitrile (SAN) containing 9.5% by weight of acrylonitrile. All gas permeability, diffusion, and solubility coefficients obtained are lower than that calculated from the semilogarithmic additivity rule. These results are qualitatively interpreted by ternary solution theory and activated state theory which have been proposed to describe gas sorption and diffusion in miscible blends. The negative deviation of gas permeabilities for the blends from this rule can be explained semiquantitatively by free volume theory which takes volume contraction on mixing into account. The negative deviation increases with gas molecular size which results in larger ideal gas separation factors than that calculated from the additivity rule. For He/CH4 and H2/CH4 pairs, the permselectivities for the blends are higher than that for either pure TMPC or SAN. The deviation from additivity for gas transport properties of TMPC/SAN blends is the opposite of that observed in the first paper of this series for PMMA/SAN blends. This can be attributed to the stronger interactions in TMPC/SAN blends than in PMMA/SAN blends.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070340414
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Plasticization of glassy polymers by CO2 (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 2633-2642 
    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 technique is described which uses differential scanning calorimetry to estimate the glass transition of polymers containing a dissolved gas. The technique is simple and appears to give reliable results. The effects of CO2 sorption at pressures up to 25 atm were examined in detail for poly(methyl methacrylate) and its blends with poly(vinylidene fluoride). Less extensive results for polystyrene, polycarbonate, poly(vinyl chloride), and poly(ethylene terephthalate) are also given. Reductions in Tg of up to 50°C are observed. A theoretical relation by Chow predicts results in reasonable agreement with the experimental data. These findings are relevant to various applications such as membrane separation processes for gases.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1985.070300626
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Polymer crystallization induced by sorption of CO2 gas (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 3911-3924 
    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: Previous work has shown that sorption of CO2 at relatively high pressures by glassy polymers reduces their glass transition temperatures and may convert the glass into a rubber under certain conditions. It is shown here that this plasticization by a gas can induce crystallization just as sorption of vapors or liquids is known to do. This point is extensively explored for miscible blends of poly(vinylidene fluoride) and poly(methyl methacrylate) and to a lesser extent for poly(ethylene terephthalate). In some cases, this secondary crystallization process results in small crystals whose melting endotherms are just above the glass transition and are very similar to peaks resulting from heat capacity overshoots, or enthalpic relaxation, caused by sub-Tg annealing; however, by appropriate techniques peaks arising from these two separate mechanisms can be distinguished. For oriented materials, evidence is shown which demonstrates that the additional crystals formed on CO2 sorption have the same preferential orientation as the original material.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1985.070300929
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Sorption and transport of gases in miscible poly(methyl acrylate)/poly(epichlorohydrin) blends (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 1173-1186 
    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 sorption and the transport of He, Ar, N2, CH4, and CO2 in miscible poly(methyl acrylate)(PMA)/poly(epichlorohydrin)(PECH) blends from 1 to 20 atm at 35°C are reported. For He, Ar, N2, and CH4, the permeabilities and the diffusion time lags are independent of the upstream pressure, if the compaction effect resulting from compression of the polymer membrane onto the supporting medium is eliminated. The permeability of CO2 increases with upstream pressure but solubility follows a simple Henry's law behavior. For all five gases, the dependence of solubility, diffusion coefficient, and permeability on blend composition are compared with theoretical mixing rules with the conclusion that both the interaction energy density and the excess activation energy for gas diffusion in the blends are near zero. The fact that the specific volumes of the blends exactly follow linear additivity also confirms that only very weak interactions exist between PMA and PECH.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1985.070300322
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Gas and vapor sorption in polymers just below Tg (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 4019-4029 
    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: Generally, sorption isotherms for gases like CO2 in glassy polymers are concave to the pressure axis, whereas in the rubbery state these isotherms are linear for gases or sometimes convex to the pressure axis for more condensable vapors. Examples of CO2 isotherms are reported here that show at low pressure the curvature characteristic of glasses and then become linear at higher pressures. This is observed when the glass transition temperature Tg is not much greater than the observation temperature T, and plasticization of the polymer by sorbed CO2 causes Tg to become equal to T within the range of pressures employed in the isotherm measurement. For the sorption of vapors in glassy polymers, this can lead to sigmoidal isotherms, as discussed using an illustration from the literature.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1985.070301006
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Gas permeation in polyethersulfone (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 33 (1987), S. 1823-1828 
    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
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070330533
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Gas permeation in miscible homopolymer-copolymer blends. I. Poly(methyl methacrylate) and styrene/acrylonitrile copolymers (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 34 (1987), S. 1037-1056 
    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: Gas transport properties in homogeneous blends of PMMA with each of two SAN random copolymers, containing 13.5 and 28% by weight of acrylonitrile respectively, have been measured at 35°C for He, H2, O2, N2, Ar, CH4, and CO2. For all cases, the permeability and diffusion coefficients are higher than that expected from the semilogarthmic additivity rule. On the other hand, the solubility coefficients and the ideal gas separation factors follow this rule well. These results for PMMA/SAN blends differ from those observed recently for other miscible blend systems; however, they agree well with recent theories proposed to describe gas sorption and permeation behavior in polymer mixtures. The composition dependence of gas transport properties observed in PMMA/SAN blends is attributed to the very weak net interactions between PMMA and SAN produced by repulsions between styrene and acrylonitrile units in the SAN random copolymers. Gas transport properties in phase-separated PMMA/SAN blends have also been studied. The phase-separated blends show sorption and permeation properties very similar to the corresponding homogeneous blends which can be explained by an isotropic, interconnected, two-phase model proposed by Kraus and Rollmann. Gas permeabilities for the solution cast PMMA films used here are compared with melt-extruded specimens used previously, and the differences are attributed to molecular orientation.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070340314
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Sorption and transport of CO2 in PVF2/PMMA Blends (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 32 (1986), S. 2897-2918 
    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 sorption and transport of CO2 in miscible PVF2/PMMA blends are reported at 35°C as a function of pressure from 1 to 25 atm. Significant plasticization by CO2 is evident for all blend compositions. This effect induced further crystallization of PVF2 for some blends, altered the shape of sorption isotherms for blends with a glassy amorphous phase, and resulted in permeabilities which increased with pressure for all compositions. Modified sorption and transport models to account for plasticization are used to analyze the data. The effect of crystallinity on observed behavior has been accounted for using approximate models to allow comparison of responses of sorption and transport with blend composition.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1986.070320106
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Gas permeation in miscible blends of poly(methyl methacrylate) with bisphenol chloral polycarbonate (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 33 (1987), S. 2935-2953 
    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 miscibility of poly(methyl methacrylate) (PMMA) with bisphenol chloral polycarbonate (BCPC) has been studied using differential scanning calorimetry (DSC), optical indication of phase separation on heating (i.e., lower critical solution temperature (LCST) behavior), density measurement, and gas permeation. All evidence indicates that PMMA is miscible with BCPC over the whole blend composition range. Single composition-dependent glass transition temperature and LCST behavior have been observed for each blend. The specific volumes of the blends follow closely the simple additivity rule indicating the interaction between PMMA and BCPC is weak. Gas permeability coefficients for He, H2, O2, Ar, N2, CH4, and CO2 measured at 35°C under 1 to 2 atm upstream pressure are lower than those calculated from the semilogarithmic additivity rule. The difference between this calculated permeability and the measured one increases with gas molecular size. As a result, the ideal gas separation factors for He/CH4, CO2/CH4, and O2/N2 gas pairs estimated from the ratio of pure gas permeabilities are higher than predicted from the semilogarithmic additivity rule. These permeation results were interpreted in terms of the free volume theory and the activated state theory, which have been proposed to describe gas transport behavior in polymer mixtures.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070330826
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...