ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Magnetism  (3,734)
  • Physics  (2,988)
  • 2015-2019  (4,061)
  • 1980-1984  (2,661)
  • 1955-1959
  • 1925-1929
  • 1
    Keywords: Physics ; Complexity, Computational ; Economic theory ; Social sciences ; Physics ; Data-driven Science, Modeling and Theory Building ; Methodology of the Social Sciences ; Economic Theory/Quantitative Economics/Mathematical Methods ; Operations Research/Decision Theory ; Complexity ; Computational Social Sciences
    Description / Table of Contents: Non-Equilibrium Social Science & Policy --- Economics --- Social Psychology and Narrative Economy --- Sociology and Non-Equilibrium Social Science --- Geography far from Equilibrium --- Cities in Disequilibrium --- The Evolutionary Theory of Globalization --- Systems, Networks, and Policy --- Towards a Complexity-Friendly Policy: breaking the vicious circle of equilibrium thinking in economic and public policy --- The Information Economy --- Complexity Science & the Art of Policy Making --- The Complexity of Government --- The Room Around the Elephant: Tackling Context-Dependency in the Social Sciences --- Global Systems Science and Policy --- Index.
    Pages: Online-Ressource (VIII, 232 pages)
    ISBN: 9783319424248
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Keywords: Physics ; Mathematical physics ; Quantum physics ; Physics ; Quantum Physics ; Mathematical Applications in the Physical Sciences ; History and Philosophical Foundations of Physics
    Description / Table of Contents: I The Cellular Automaton Interpretation as a general doctrine: Motivation for this work --- Deterministic models in quantum notation --- Interpreting quantum mechanics --- Deterministic quantum mechanics --- Concise description of the CA Interpretation --- Quantum gravity --- Information loss --- More problems --- Alleys to be further investigated and open questions --- Conclusions --- II Calculation Techniques: Introduction to part II --- More on cogwheels --- The continuum limit of cogwheels, harmonic rotators and oscillators --- Locality --- Fermions --- PQ theory --- Models in two space-time dimensions without interactions --- Symmetries --- The discretised Hamiltonian formalism in PQ theory --- Quantum Field Theory --- The cellular automaton --- The problem of quantum locality --- Conclusions of part II --- Some remarks on gravity in 2+1 dimensions --- A summary of our views on Conformal Gravity --- Abbreviations.
    Pages: Online-Ressource (XVIII, 298 pages) , 21 illustrations, 19 illustrations in color
    ISBN: 9783319412856
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Mathematics ; Computer graphics ; Dynamics ; Ergodic theory ; Functions of complex variables ; Differential geometry ; Physics ; Mathematics ; Differential Geometry ; Functions of a Complex Variable ; Dynamical Systems and Ergodic Theory ; Computer Graphics ; Numerical and Computational Physics
    Description / Table of Contents: Discrete conformal maps: Boundary value problems, circle domains, Fuchsian and Schottky uniformization: Alexander I. Bobenko, Stefan Sechelmann, Boris Springborn --- Discrete complex analysis on planar quad-graphs: Alexander I. Bobenko and Felix Günther --- Approximation of conformal mappings using conformally equivalent triangular lattices: Ulrike Bücking --- Numerical Methods for the Discrete Map Za: Folkmar Bornemann, Alexander Its, Sheehan Olver, and Georg Wechslberger --- A variational principle for cyclic polygons with prescribed edge lengths: Hana Kourimská, Lara Skuppin, Boris Springborn --- Complex Line Bundles over Simplicial Complexes and their Applications: Felix Knöppel and Ulrich Pinkall --- Holomorphic vector fields and quadratic differentials on planar triangular meshes: Wai Yeung Lam, Ulrich Pinkall --- Vertex normals and face curvatures of triangle meshes: Xiang Sun, Caigui Jiang, Johannes Wallner, and Helmut Pottmann --- S-conical cmc surfaces. Towards a unified theory of discrete surfaces with constant mean curvature: Alexander I. Bobenko and Tim Hoffmann --- Constructing solutions to the Björling problem for isothermic surfaces by structure preserving discretization: Ulrike Bücking and Daniel Matthes --- On the Lagrangian Structure of Integrable Hierarchies: Yuri B. Suris, Mats Vermeeren --- On the variational interpretation of the discrete KP equation: Raphael Boll, Matteo Petrera, and Yuri B. Suris --- Six topics on inscribable polytopes: Arnau Padrol and Günter M. Ziegler --- DGD Gallery: Storage, sharing, and publication of digital research data: Michael Joswig, Milan Mehner, Stefan Sechelmann, Jan Techter, and Alexander I. Bobenko
    Pages: Online-Ressource (X, 439 pages) , 114 illustrations, 67 illustrations in color
    ISBN: 9783662504475
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Keywords: Environment ; Climate change ; Remote sensing ; Physics ; Environment ; Climate Change ; Remote Sensing/Photogrammetry ; Energy Efficiency ; Climate Change/Climate Change Impacts ; Applied and Technical Physics
    Description / Table of Contents: Part I The Urban Heat Island – Evidence, Measures and Tools --- Forecasting Models for Urban Warming in Climate Change --- Assessment Indication and Gold Standard --- Methodologies for UHI Analysis --- Decision Support Systems for Urban Planning --- Part II Pilot Actions in European Cities --- Counteracting Urban Heat Islands: Solutions for European Cities.
    Pages: Online-Ressource (LIII, 400 pages) , 213 illustrations
    ISBN: 9783319104256
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Keywords: Environment ; Climate change ; Remote sensing ; Physics ; Environment ; Climate Change ; Remote Sensing/Photogrammetry ; Energy Efficiency ; Climate Change/Climate Change Impacts ; Applied and Technical Physics
    Description / Table of Contents: Part I The Urban Heat Island – Evidence, Measures and Tools --- Forecasting Models for Urban Warming in Climate Change --- Assessment Indication and Gold Standard --- Methodologies for UHI Analysis --- Decision Support Systems for Urban Planning --- Part II Pilot Actions in European Cities --- Counteracting Urban Heat Islands: Solutions for European Cities.
    Pages: Online-Ressource (LIII, 400 pages) , 213 illustrations
    ISBN: 9783319104256
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Keywords: Physics ; Matrix theory ; Algebra ; Mathematical physics ; Quantum physics ; Physics ; Quantum Physics ; Mathematical Physics ; History and Philosophical Foundations of Physics ; Linear and Multilinear Algebras, Matrix Theory
    Description / Table of Contents: Introduction --- Part I Co(X) and B(H): Classical physics on a finite phase space --- Quantum mechanics on a finite-dimensional Hilbert space --- Classical physics on a general phase space --- Quantum physics on a general Hilbert space --- Symmetry in quantum mechanics --- Part II Between Co(X) and B(H): Classical models of quantum mechanics --- Limits: Small hbar --- Limits: large N --- Symmetry in algebraic quantum theory --- Spontaneous Symmetry Breaking --- The Measurement Problem --- Topos theory and quantum logic --- Appendix A: Finite-dimensional Hilbert spaces --- Appendix B: Basic functional analysis --- Appendix C: Operator algebras --- Appendix D: Lattices and logic --- Appendix E: Category theory and topos theory --- References
    Pages: Online-Ressource (XXXVI, 861 pages) , 9 illustrations, 8 illustrations in color
    ISBN: 9783319517773
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Keywords: Physics ; Quantum optics ; Physics ; Optics, Lasers, Photonics, Optical Devices ; Quantum Optics ; Popular Science in Physics ; History and Philosophical Foundations of Physics
    Description / Table of Contents: History --- A brief history of light --- Ibn Al-Haitham – Father of modern optics --- Optical Sources --- Femtosecond light --- Laser --- LED light --- Electron optics --- Applications --- Biophotonics --- Optical communication --- Optical astronomy --- Solar cells --- Optics in Remote Sensing --- Optics in nanotechnology --- Optics in art --- Eye --- Optics in medicine --- Optical illusions --- Quantum Optics --- Optical tests of foundations of physics --- Nonlinear Optics: Historical Perspectives and New Opportunities --- Quantum communication --- Nature of photon --- Atom optics --- Coherent effects: From EIT to slow light
    Pages: Online-Ressource (XX, 504 pages) , 355 illustrations, 277 illustrations in color
    ISBN: 9783319319032
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Keywords: Physics ; History ; Nuclear physics ; Heavy ions ; Hadrons ; Particle acceleration ; Physics ; Nuclear Physics, Heavy Ions, Hadrons ; History and Philosophical Foundations of Physics ; Particle Acceleration and Detection, Beam Physics ; History of Science
    Description / Table of Contents: Part I Reminiscences: Rolf Hagedorn and Relativistic Heavy Ion Research.-- Part II The Hagedorn Temperature --- Part III Melting Hadrons, Boiling Quarks Heavy Ion Path to Quark-Gluon Plasma --- Acronyms
    Pages: Online-Ressource (XVI, 441 pages)
    ISBN: 9783319175454
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Keywords: Physics ; Mathematical physics ; Quantum physics ; Physics ; Quantum Physics ; Mathematical Applications in the Physical Sciences ; History and Philosophical Foundations of Physics
    Description / Table of Contents: I The Cellular Automaton Interpretation as a general doctrine: Motivation for this work --- Deterministic models in quantum notation --- Interpreting quantum mechanics --- Deterministic quantum mechanics --- Concise description of the CA Interpretation --- Quantum gravity --- Information loss --- More problems --- Alleys to be further investigated and open questions --- Conclusions --- II Calculation Techniques: Introduction to part II --- More on cogwheels --- The continuum limit of cogwheels, harmonic rotators and oscillators --- Locality --- Fermions --- PQ theory --- Models in two space-time dimensions without interactions --- Symmetries --- The discretised Hamiltonian formalism in PQ theory --- Quantum Field Theory --- The cellular automaton --- The problem of quantum locality --- Conclusions of part II --- Some remarks on gravity in 2+1 dimensions --- A summary of our views on Conformal Gravity --- Abbreviations.
    Pages: Online-Ressource (XVIII, 298 pages) , 21 illustrations, 19 illustrations in color
    ISBN: 9783319412856
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Keywords: Physics ; History ; Nuclear physics ; Heavy ions ; Hadrons ; Particle acceleration ; Physics ; Nuclear Physics, Heavy Ions, Hadrons ; History and Philosophical Foundations of Physics ; Particle Acceleration and Detection, Beam Physics ; History of Science
    Description / Table of Contents: Part I Reminiscences: Rolf Hagedorn and Relativistic Heavy Ion Research.-- Part II The Hagedorn Temperature --- Part III Melting Hadrons, Boiling Quarks Heavy Ion Path to Quark-Gluon Plasma --- Acronyms
    Pages: Online-Ressource (XVI, 441 pages)
    ISBN: 9783319175454
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Keywords: Physics ; Complexity, Computational ; Economic theory ; Social sciences ; Physics ; Data-driven Science, Modeling and Theory Building ; Methodology of the Social Sciences ; Economic Theory/Quantitative Economics/Mathematical Methods ; Operations Research/Decision Theory ; Complexity ; Computational Social Sciences
    Description / Table of Contents: Non-Equilibrium Social Science & Policy --- Economics --- Social Psychology and Narrative Economy --- Sociology and Non-Equilibrium Social Science --- Geography far from Equilibrium --- Cities in Disequilibrium --- The Evolutionary Theory of Globalization --- Systems, Networks, and Policy --- Towards a Complexity-Friendly Policy: breaking the vicious circle of equilibrium thinking in economic and public policy --- The Information Economy --- Complexity Science & the Art of Policy Making --- The Complexity of Government --- The Room Around the Elephant: Tackling Context-Dependency in the Social Sciences --- Global Systems Science and Policy --- Index.
    Pages: Online-Ressource (VIII, 232 pages)
    ISBN: 9783319424248
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Keywords: Physics ; Epistemology ; Philosophy and science ; Probabilities ; Physics ; History and Philosophical Foundations of Physics ; Theoretical, Mathematical and Computational Physics ; Epistemology ; Probability Theory and Stochastic Processes ; Philosophy of Science
    Description / Table of Contents: Part I Embedded observers, reflexive perception and representation: Intrinsic and extrinsic observation mode --- Embedded observers and self-expression --- Reflexive measurement --- Intrinsic self-representation --- Part II Provable unknowns: On what is entirely hopeless --- Forecasting and unpredictability --- Induction by rule inference --- Other types of recursion theoretic unknowables --- What if there are no laws? Emergence of laws --- Part III Quantum unknowns: "Shut up and calculate" --- Evolution by permutation --- Quantum mechanics in a nutshell --- Quantum oracles --- Vacuum fluctuations --- Radioactive decay --- Part IV Exotic unknowns: Classical continua and infinities --- Classical (in)determinism --- Deterministic chaos --- Partition logics, finite automata and generalized urn models --- Part V Transcendence: Miracles --- Dualistic interfaces --- Part VI Executive summary: Executive summary --- Appendix A: Formal (in)computability and randomness --- B: Two particle correlations and expectations
    Pages: Online-Ressource (XIV, 219 pages) , 32 illustrations, 24 illustrations in color
    ISBN: 9783319708157
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Unknown
    Berlin, Heidelberg : Springer
    Keywords: Mathematics ; Computer graphics ; Dynamics ; Ergodic theory ; Functions of complex variables ; Differential geometry ; Physics ; Mathematics ; Differential Geometry ; Functions of a Complex Variable ; Dynamical Systems and Ergodic Theory ; Computer Graphics ; Numerical and Computational Physics
    Description / Table of Contents: Discrete conformal maps: Boundary value problems, circle domains, Fuchsian and Schottky uniformization: Alexander I. Bobenko, Stefan Sechelmann, Boris Springborn --- Discrete complex analysis on planar quad-graphs: Alexander I. Bobenko and Felix Günther --- Approximation of conformal mappings using conformally equivalent triangular lattices: Ulrike Bücking --- Numerical Methods for the Discrete Map Za: Folkmar Bornemann, Alexander Its, Sheehan Olver, and Georg Wechslberger --- A variational principle for cyclic polygons with prescribed edge lengths: Hana Kourimská, Lara Skuppin, Boris Springborn --- Complex Line Bundles over Simplicial Complexes and their Applications: Felix Knöppel and Ulrich Pinkall --- Holomorphic vector fields and quadratic differentials on planar triangular meshes: Wai Yeung Lam, Ulrich Pinkall --- Vertex normals and face curvatures of triangle meshes: Xiang Sun, Caigui Jiang, Johannes Wallner, and Helmut Pottmann --- S-conical cmc surfaces. Towards a unified theory of discrete surfaces with constant mean curvature: Alexander I. Bobenko and Tim Hoffmann --- Constructing solutions to the Björling problem for isothermic surfaces by structure preserving discretization: Ulrike Bücking and Daniel Matthes --- On the Lagrangian Structure of Integrable Hierarchies: Yuri B. Suris, Mats Vermeeren --- On the variational interpretation of the discrete KP equation: Raphael Boll, Matteo Petrera, and Yuri B. Suris --- Six topics on inscribable polytopes: Arnau Padrol and Günter M. Ziegler --- DGD Gallery: Storage, sharing, and publication of digital research data: Michael Joswig, Milan Mehner, Stefan Sechelmann, Jan Techter, and Alexander I. Bobenko
    Pages: Online-Ressource (X, 439 pages) , 114 illustrations, 67 illustrations in color
    ISBN: 9783662504475
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Keywords: Physics ; Nuclear energy ; International relations ; Physics ; Applied and Technical Physics ; Societal Aspects of Physics, Outreach and Education ; Nuclear Energy ; International Relations
    Description / Table of Contents: This open access book examines key aspects of international cooperation to enhance nuclear safety, security, safeguards, and non-proliferation, thereby assisting in development and maintenance of the verification regime and fostering progress toward a nuclear weapon-free world. The book opens by addressing important political, institutional, and legal dimensions. Current challenges are discussed and attempts made to identify possible solutions and future improvements. Subsequent sections consider scientific developments that have the potential to increase the effectiveness of implementation of international regimes, particularly in critical areas, technology foresight, and the ongoing evaluation of current capabilities. The closing sections examine scientific and technical challenges and discuss the role of international cooperation and actions of the scientific community in leading the world toward peace and security. The book – which celebrates 60 years of IAEA Atoms for Peace and Development and the EURATOM Treaty – comprises contributions presented at the XX Edoardo Amaldi Conference, where eminent scientists, diplomats, and policymakers were able to compare national perspectives and update international collaborations
    Pages: Online-Ressource (XXXVI, 220 pages) , 16 illustrations in color
    ISBN: 9783662573662
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Unknown
    Amsterdam ; New York : North-Holland Pub. Co
    Keywords: DDC 530.1 ; LC QC20 ; Mathematical physics ; Physics ; Quantum theory ; Relativity (Physics)
    ISBN: 9780444875853
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Keywords: Physics ; Quantum field theory ; String theory ; Elementary particles (Physics) ; Physics ; Elementary Particles, Quantum Field Theory ; Quantum Field Theories, String Theory
    Description / Table of Contents: Preface --- Gauge Theories and the Standard Model --- QCD: The Theory of Strong Interactions --- The Theory of Electroweak Interactions --- References
    Pages: Online-Ressource (XIV, 173 pages) , 60 illustrations, 34 illustrations in color
    ISBN: 9783319519203
    Language: English
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 113 (1982), S. 275-284 
    ISSN: 1434-4475
    Keywords: Ferromagnetic properties ; Heusler alloys ; Magnetism ; Paramagnetic properties
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung QuarternäreHeusler-Legierungen der Zusammensetzung (Ni1−x Cu x )2MnSn wurden über den Konzentrationsbereichx=0–1 hergestellt. Alle waren einphasig und zeigten L 21-Struktur. Magnetische Messungen wurden sowohl im ferromagnetischen als auch im paramagnetischen Bereich durchgeführt. Sie ergaben für Mn, das einzige Atom das in dieser Art vonHeusler-Legierungen ein Moment zeigt, den üblichen Wert von ca. 4 µB und ein ihm entsprechendes μeff im paramagnetischen Bereich. Ein flaches Minimum derCurietemperatur kann mit Hilfe von di-dl-Wechselwirkung erklärt werden.
    Notes: Abstract QuarternaryHeusler alloys of composition (Ni1−x Cu x )2MnSn were prepared withx=0–1. They were all single phased with L21 structure. Alloys were investigated by magnetic measurements. For Mn, the only atom carrying a moment in this kind ofHeusler alloys, the usual value (∼4 µB) was found and a corresponding μeff in the paramagnetic region. A shallow minimum of theCurie temperatures can be explained on the basis of di-dl interaction.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Pure and applied geophysics 120 (1982), S. 375-388 
    ISSN: 1420-9136
    Keywords: Gravity ; Magnetism ; Scotland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract From our interpretation of the Bouguer gravity and aeromagnetic anomalies in south-east Scotland, we conclude that a massive granite batholith underlies the greater part of the eastern Southern Uplands. The granite model which we computed earlier from gravity anomalies in the Tweeddale area fits the observed magnetic anomalies closely, if a normal magnetization of 0.095 A m−1 is assigned, similar to values found for exposed local granites. Further gravity modelling shows that, apart from the Tweeddale boss, the granite shallows to less than 1 km near Lammer Law in East Lothian and extends north of the Lammermuir Fault. A model for the East Lothian volcanics was computed from their aeromagnetic anomalies, then their gravitational effect was combined with that estimated for the Devonian and Carboniferous sediments and the result stripped off the observed gravity field. The residual gravity anomalies were used to generate a two-dimensional model for the granite north of the Lammermuir Fault. The expected tectonic consequences of a massive granite batholith in the eastern Southern Uplands are compared with the known development of faults and sedimentary basins around its margins.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1237-1242 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Electron microscopy reveals a high-temperature morphological transition in a styrene-butadiene-styrene block copolymer of 7000 polystyrene block molecular weight and 43,000 polybutadiene block molecular weight (7S-43B-7S). Samples quenched in liquid nitrogen from temperatures above 150°C show no structure, whereas those quenched from temperatures below 140°C clearly show a multiphase structure. We previously reported that the 7S-43B-7S polymer exhibits a relatively sharp melt rheological transition in the temperature region between 140 and 150°C from highly viscoelastic and nonlinear viscous behavior to linear viscous behavior with insignificant elasticity. The dynamic viscoelastic properties are measured at different strain amplitudes in this study, and the results show that the melt rheological transition behavior is not influenced by the strain amplitude. This study clearly shows that the melt rheological transition in the 7S-43B-7S results from a morphological transition from a multiphase structure below about 140°C to a single-phase structure above about 150°C.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1257-1270 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The intensity of the glass transition in semicrystalline polycarbonate was measured by differential scanning calorimetry and by thermally stimulated discharge of electrets. Solution-cast and bulk-crystallized samples possessing widely varying crystallinities and morphologies were investigated. It is shown that the intensity of the glass transition is governed by the extent of primary crystallization and is a linear combination of intensities from the bulk amorphous regions and from noncrystalline polymer within semicrystalline aggregates such as spherulites. The intensity of the glass transition within spherulites is about 0.1-0.3 as great as that in bulk amorphous regions. A three-phase model incorporating two distinct types of noncrystalline polycarbonate is proposed to account for the properties of this polymer.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1311-1324 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A detailed description of the morphology and the complex melting behavior of poly(ethylene terephthalate) crystallized isothermally in the range 100-245°C is presented. Double or single melting endotherms can deliberately be obtained by varying the heating rate in the differential scanning calorimeter (DSC). In the case of double melting peaks, the first endotherm (I) corresponds to the melting of the crystalline material formed at the crystallization temperature Tc. The second melting endotherm (II) originates from the melting of a fraction of the original crystalline material reorganized during the DSC scan. The appearance of one melting endotherm (I or II) relates to the melting of the original structure or the melting of a completely transformed structure. Taking the end of the melting endotherm I as the final melting temperature TM of the material, an equilibrium melting temperature of 290°C is obtained from a plot of TM vs. Tc. A detailed morphological study of the isothermally crystallized samples by electron microscopy and both small-angle and wide-angle x-ray scattering raises questions about the use of the two-phase concept in relating morphological parameters and melting behavior at low crystallization temperatures.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1361-1381 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A temperature-dependent small-angle x-ray scattering and electron microscopic study on a sample of low-density polyethylene affords a determination of the structure changes in a heating and cooling cycle and suggests a new model of partial crystallization and melting. The analysis of SAXS data is based upon some general properties of the electron-density correlation function. Electron micrographs are obtained from stained sections γ irradiated at elevated temperatures and are analyzed quantitatively by statistical means. According to the model proposed here the thickness distribution in the amorphous layers, rather than that of the crystalline regions, is the essential factor governing the crystallization and melting behavior. The temperature-dependent changes in this thickness distribution provide a natural explanation for the large reversible changes in long-spacing.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1421-1431 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Solid solutions of two low-molecular-weight polyethylene fractions, formed by rapid quenching from the melt, were studied by differential scanning calorimetry, low-frequency Raman spectroscopy, and Fourier-transform infrared spectroscopy. Two kinds of defects exist in these solid solutions; namely, a disruption of chain extension and the presence of monoclinic packing. The distribution of fully extended chain-segment lengths and the intensity of the 717 cm-1 infrared band, characteristic of the monoclinic phase, are found to be composition dependent. Our spectroscopic studies of the solid solutions support the model first proposed by Ott and Slagle.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1413-1419 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The thermal behavior of α nylon-12 film cast from a phenol-ethanol mixture has been studied by differential scanning calorimetry. Polymorphism has been analyzed by x-ray diffraction. The γ form exhibits a single endothermic melting peak in the thermogram, whereas the α form exhibits double peaks. Samples with mixed α and γ forms show double peaks at the same positions and the area ratio changes in accordance with the amounts of the two forms. The appearance of the γ peak, even for the α sample, is explained by recrystallization to the γ form after melting of the α form. The melting point of α nylon-12 is ca. 173°C, which is lower by 6-7° than that of the γ form. Once the α or γ sample has been melted and then cooled, its heating thermogram shows a small peak before the appearance of the main peak. The small peak seems to be due to incomplete and/or smaller crystallites formed during cooling. Heat treatment below the melting point of α nylon-12 is effective in transforming the α form to the γ form, probably via a melt-recrystallization process.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1433-1438 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A 40:60 mole ratio poly(ethylene terephthalate-co-p-oxybenzoate) was studied by dynamic scanning calorimetry. Vitrification occurred in two steps, which could be linked by optical microscopy to a two-phase structure. For the lower glass transition, hysteresis was absent on heating and cooling through the transition temperature. Since all prior studied glasses show such hysteresis, this may be linked to the mesophase structure and raises the question whether mesophases always display such glass-transition behavior.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1469-1480 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A small-angle x-ray scattering (SAXS) investigation of two linear segmented polyurethanes was carried out to learn about the respective domain structure (morphology). Both urethanes had a hard segment of methylene-bis(4)phenyl isocyanate (MDI) and butanediol. These two components comprised 28% by weight of each system. The soft segments differed in that one was a polyether (tetramethylene oxide, molecular weight 1000), while the other was a polyester (polytetramethylene adipate, molecular weight 1000). Both of these segmented urethanes were stored at room temperature for over 6 months prior to investigation. Using an automated Kratky camera, SAXS scans were made. By detailed analysis (using the computer program of Vonk) the average interfacial thickness E of the domains was determined by two approaches. The value of E for the polyester was 10-12 Å, while it was 5-7 Å for the polyether. Within the limits of the assumptions used for analysis, these data directly support the conjecture that polyether urethanes generally lead to better phase separation. Other aspects of the analysis provided further information on the morphological structure. Some cautionary comments are provided on the use of quantitative SAXS data obtained from these or similar systems.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1481-1482 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1513-1522 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The melting behavior of low-density polyethylene was studied by electron microscopy. The experimental techniques and method of evaluation chosen were such as to deliver quantitative numerical data. The values which could be derived from suitably prepared histograms were the minimum, maximum, average, and most probable values of the crystal thickness d and long-spacing L. All these values were in good agreement with small-angle x-ray scattering results. The histograms also show the distribution functions for d and L, so that effects leading to changes in the average values can be observed in detail. The results provide further support for a model of melting and crystallization proposed in a previous paper.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The kinetics of crystallization and structure formation of polycaproamide (PCA) during anionic adiabatic polymerization of ε-caprolactam was studied. The adiabatic crystallization was shown to comprise three successive stages. In the first stage PCA forms dendritelike structures, the space between which is filled with the monomer. In the second stage rather rapid crystallization proceeds to give large loose spherulites. The dendritic structures serve as nuclei for development of spherulites. In the third stage slow secondary crystallization occurs. It is accomplished by crystallization of the residual amorphous substance located both in the dendritic nucleus and throughout the volume of the spherulites. This process is followed by the partial disappearance of the dendritic nuclei and by thickening of lamellae, which results in a substantial densification of initial structures and appearance of fine spherulites. As a result, a fine spherulitic structure with 50% crystallinity is formed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1533-1559 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An enquiry is presented into the nature and origin of thermoreversible gelation of poly(vinyl chloride) (PVC). In line with a previous paper it is demonstrated by direct x-ray diffraction evidence that the origin of the gelation is crystallization, and that this crystallinity can be conspicuously apparent even for the usual technological polymer. In addition some unusual diffraction effects become apparent such as do not obviously follow from existing notions of the PVC structure. Combined infrared dichroism and x-ray studies revealed that these new effects are attributable to a two-component nature of the crystallinity where the components are distinguished by their orientation behavior, lateral extension, and possibly morphology of the crystallites. Some of the crystals orient with their a axes (type A crystals) and some with their c axes (type B crystals) along the stretch direction. Other more complex orientability differences are also manifest during film formation. Crystals B are smaller, and are believed to correspond to the network forming junctions, hence to fringed micellar crystals. Crystals A have a less evident connection with the network and are hypothesized to be of lamellar character, the behavior of which is closely simulated by lamellar crystal additives (stabilizer crystals). High-temperature x-ray work revealed no melting of crystals even in the temperature range where endotherms appear in the thermograms.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1587-1597 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Monad, dyad, and triad populations have been derived from the 13C NMR spectra of eight ethylene-propylene copolymers. Using these values, Kinetic parameters of the polymerization have been calculated, including conditional probabilities, and reactivity ratios. The fraction of propylene entering in an inverted order has been found to be about 20%. The copolymerization is dominated by the relatively large reactivity of ethylene. There is an alternating tendency for the two monomers which is evident both in the normal addition of propylene and the inverted addition. Penultimate effects do not play a significant role.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1621-1632 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The permeability and time lag at pressures below 1 atm were measured for carbon dioxide in five polystyrene samples with different molecular weights at 25 to 40°C. The apparent permeability coefficient decreases with increasing carbon dioxide pressure and also decreases with increasing molecular weight of polystyrene, whereas the apparent diffusion coefficient calculated from time lag increases with pressure and is independent of molecular weight. Parameters for the partial-immobilization model were determined from the apparent diffusion and permeation coefficients by using a nonlinear least-squares optimization program without using sorption data. The results suggest that the void-saturation constant C′H decreases as the molecular weight of the polymer increases or as the chain-end free volume decreases. The significance of these observation and their interpretation is discussed in terms of free-volume theory for glassy polymers.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1643-1650 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Changes in density and in the corresponding degree of crystallinity with radiation dose are studied experimentally for γ-irradiated polytetrafluoroethylene (PTFE) in the dose range from 1 X 103 to 1 X 109 R. The relation between the amorphous fraction and the radiation dose is derived from a quantitative analysis of cold crystallization by scission of polymer backbone chains. The characteristic radiation dose, at which one break occurs on the average per initial molecule, is estimated as about 3 X 104 R on the basis of a derived kinetic equation. The theoretical relation is modified by considering microvoids produced in the irradiated samples. The radii of microvoids in the form of spheres are evaluated as about 0.2 nm, and are also related to cage spheres relevant to the chain scission process. Good agreement between the modified theoretical relation and experimental data is attained over the entire range of radiation dose.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1663-1664 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1673-1683 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Light scattering and viscometric studies have been carried out on dilute solutions of a polybenzimidazole in N,N-dimethylacetamide. The data, which span the molecular weight range 2.9 ≦ 10-4Mw ≦ 23.3, and the temperature range 290 ≦ T/K ≦343, yield the dependence of the mean-square radius of gyration 〈s2〉LS, the second virial coefficient A2, and the intrinsic viscosity [η] on molecular weight Mw and temperature. The unperturbed mean-square radius 〈s20〉LS was calculated using experimental values of 〈s2〉LS and A2. It was found that excluded volume effects on 〈s2〉LS are very small. The unperturbed hydrodynamic chain dimension 〈s20〉η was estimated by considering draining effects. A small value of the draining parameter was obtained. Analysis of the temperature dependence of A2 and [eta;] leads to the conclusion that this system approaches a lower theta temperature with increasing temperature. The steric factor σ = 〈s20〉/〈s20〉f, based on the value of 〈s20〉f calculated for the polymer chain with free rotation, is nearly unity. Most of these properties can be interpreted in terms of long rotational units within the main chain.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1707-1716 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An anisotropic dispersive continuum model for the collective modes of polyethylene of any degree of crystallinity is suggested. The model successfully explains the experimental results for specific heat of polyethylene of 100%, 84.1%, 74.5%, 45.9%, and 0% crystallinity in the temperature range 2.5-60 K, where the specific heat of amorphous polyethylene is markedly different from that of crystalline polyethylene. The variation of specific heat with degree of crystallinity can be obtained by varying only one parameter θ1 (characterizing the low energy cubic modes), keeping the other two parameters (characterizing the transverse and longitudinal chain modes) constant. Thus, in going from the crystalline to the amorphous state, it is essentially the interchain binding which is affected, the chain modes being left undisturbed. Using the calculated values of specific heat for varying degrees of crystallinity, the variation of θ1 with the crystallinity is reported. Observed high-temperature specific heats for crystalline and amorphous polyethylene up to 300 K are also explained using additional optical modes. The anisotropic Mössbauer elastic scattering fraction (MESF) for polyethylene of different degrees of crystallinity in the temperature range 0-425 K is obtained. For a given degree of crystallinity there is marked anisotropy in MESF which increases with increase in temperature. For a given direction, longitudinal or transverse, there is a large difference between the MESF of 0% and 100% crystalline polyethylene, which also increases with the increase in temperature. It is quite possible that the MESF experiment may prove to be more sensitive than the usual method for the determination of degree of crystallinity.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1747-1752 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Previous work has shown that in the environmental stress cracking (ESC) of polyethylene, there are three major zones of behavior depending on the applied stress and the nature of the liquid environment. These three zones correspond to “pure” ESC (zone 1), ESC controlled by the speed of penetration of the liquid within a growing crack (zone 2), and behavior as in the absence of liquid (zone 3). Analysis of the transitions between zones has shown that, in the present case, a given liquid will either be capable of giving rise to all three types of behavior depending on the stress applied, or will be totally inactive. A related analysis has enabled the order of magnitude of the dimensions of the crack tip to be estimated and this has been found to be in the range of a micron.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1771-1780 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Smith-Ewart Case-2 kinetics are applied to a continuous stirred tank reactor operating at steady state in the high and middle range of conversion. Above the conversion CD at which the monomer droplets disappear in a batch reaction, the predictions are surprising. The particle size is predicted to be inversely proportional to the effective soap concentration S and independent of mean residence time θ below CD it is predicted to be proportional to the one-third power of θ and independent of S. Above CD the particle concentration should be proportional to the cube of S and independent of θ; below this it should be as predicted by previous workers. The expressions for conversion are also different above CD. A new, more instructive, derivation is used. Simple analytic expressions are given for commonly used breadth parameters of the particle size distribution. It is shown that when conversion is low, an approximation made by previous workers is invalid, in that the growth rate can no longer be considered continuous.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1847-1851 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1879-1890 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Fluorescence polarization was used to measure segmental orientation in stretched polyisoprene networks. Stress and orientation of chemically bonded fluorescent labels were simultaneously recorded during stretching. Two deviations from the classical theory of rubber elasticity were observed: (i) an extra orientation of dry networks, which was interpreted by assuming the existence of weak nematiclike interactions between segments, and (ii) a saturation of orientation at high elongation which could be due to local conformational changes.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1907-1917 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The measurement of the sedimentation velocity coefficient of narrow distribution linear, four-arm and six-arm star and comb polystyrenes in a theta solvent permits the experimental determination of h, i.e., the ratio of the translational friction coefficients of the branched polymer to that of its linear homolog. A comparison of experimental h/g1/2 values with theoretical predictions can then be made. It was observed that the equivalent hydrodynamic radii derived from sedimentation and intrinsic viscosity measurements are identical within experimental error.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1945-1954 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: X-ray diffraction, thermally stimulated depolarization, and piezoelectric and pyroelectric current measurements have been carried out on biaxially oriented polyvinylidene fluoride film, corona-poled both negatively and positively, at elevated temperature. Larger piezoelectric and pyroelectric coefficients are obtained at lower values of the poling field, when corona charging takes place at elevated temperature rather than room temperature. Negative charging is more effective than positive. The polarization mechanism is dipole alignment, and a conversion of Form-II crystallites to Form I. The large space-charge injected by the corona, and trapped in the material, acts through creation of high internal fields, and shows little, if any, piezoelectric and pyroelectric effects of its own.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 1963-1978 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Concentrated solutions of transferrin, albumin, immunoglobulin, chymotrypsinogen, transfer-RNA, dextran, and polystyrene were pelleted in the analytical ultracentrifuge. The proteins developed a solvent/pellet boundary which was chracterized at equilibrium by an asymmetric schlieren peak with a “shoulder”. The schlieren curve was at the same level inside the protein pellet as in the solvent above the pellet, indicating that the protein molecules had been packed homogeneously. The protein concentration in the pellet ranged from 0.6 to 0.7 g/ml. Immediately after deceleration was begun, the “shoulder” of the pellet boundary changed into a very sharp peak, leading to a boundary composed of two schlieren peaks. Sedimentation rates were measured for transferrin solutions at concentrations up to 0.3 g/ml.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2015-2025 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In a previous paper, the extents of reaction of various functional groups in different acrylic copolymer melamine-formaldehyde crosslinked formulations were measured by infrared spectroscopy. From these data and a statistical model, various network structure parameters could be calculated. One of these, effective crosslink density, was found to correlate well with film solvent resistance. In this paper the effects of the addition of strong acid catalysts on cure chemistry and network structure are determined. Both solvent-based and water-based formulations have been studied. In the solvent-based formulations studied, the addition of acid catalysts greatly enhanced the crosslinking reactions at low temperatures and dramatically lowered the cure temperature. Acid catalysts also lowered the cure temperature of a water-based formulation based on a high (180°C) cure temperature melamine. In contrast, the addition of acid catalysts had a negligible effect on the cure chemistry of a water-based formulation crosslinked with a low (130°C) cure temperature melamine. For this case the rate limiting process was found to be the rate of removal of neutralizing amine from the film. Cure temperatures in this system could only be lowered by replacing the amine used with a more volatile amine.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2055-2067 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In deriving a constitutive equation from a molecular model of polymers in concentrated solutions and melts, Doi and Edwards used a mathematical approximation, the “independent alignment approximation,” which has recently been shown to produce significant error in the particular case of stress relaxation following a double-step strain in opposite direction. In the present paper, in order to examine the approximation in general cases, we derive a new constitutive equation without using the independent alignment approximation. The new equation is a nonlinear integro-differential equation and is solved numerically for several cases, i.e., steady shear and elongational flows, and the transient flows after the start of shear and elongation. It is found that, in the cases examined here, the new constitutive equation gives nearly the same results as the old one: the rheological functions calculated from the two theories differ no more than 30%. This substantiates the expectation that the independent alignment approximation does not produce drastic error as long as the flow direction is not reversed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2083-2096 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The specific concentration ca of methylene chloride, the zero-concentration diffusion coefficient D0, and the concentration coefficient γD of the diffusivity in drawn and annealed LDPE were measured. The influence of the drawing rate, of annealing with the ends of the sample free and fixed and the effects of time of standing at room temperature after annealing were investigated. The observed transport properties are in good agreement with the microfibrillar model of fibrous structure, its relaxation during annealing, and the slow crystallization of relaxed tie-molecules upon standing at room temperature.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2149-2153 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2181-2196 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A piston-cylinder-type high-pressure dilatometer has been built and the effect of pressure on melting behavior of poly(ethylene terephthalate) (PET) has been studied. The melting temperature increases but the rate of change of the melting temperature decreases with increasing pressure. Poly(ethylene terephthalate) crystallized from the melt at elevated pressure and temperature was studied by thermal analysis, and wide-angle and small-angle x-ray diffraction and electron microscopy. Chain-extended PET crystals were observed for the first time and some of their properties are described. A similarity to extended-chain polyethylene is suggested.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2227-2241 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Heat capacities Cp of a polydiacetylene-bis(toluene sulfonate) single crystal and its monomer have been measured in the temperature range from 3 to 300 K. The temperature dependence of Cp for both monomer and polymer crystals differs from that for monoatomic solids. By applying a chain lattice model for a polymer crystal, the temperature dependence of the heat capacity can be described assuming a phonon density of states given by bending and stretching modes of the polymer backbone. With a combination of one-dimensional and three-dimensional elastic continuum approximations, the heat capacity has been calculated and a good fit to the data has been obtained. A small peak in Cp was detected at 161 K for the monomer and at 198 K for the polymer. This may be ascribed to a lower-temperature phase transition in the polydiacetylene crystals evidenced by previous x-ray and spectroscopic measurements.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2257-2261 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: There has been a growing interest in compatible blends in which one of the polymers is crystallizable. At appropriate compositions some of this polymer will crystallize, the remainder forms a compatible blend with the other polymer component; attempts have been made to relate melting point depression of the crystalline component to diluent effects, i.e., polymer/polymer interactions. Melting point is also a function of lamella thickness, the determination of which is very difficult in such systems. It is assumed in this type of study that the melting point of a crystal in an incompatible matrix will be unchanged. In an attempt to test this assumption we have determined the melting behavior of isothermally grown, single crystals of polyethylen (from the same preparation) embedded in a variety of incompatible matrices. The matrices used were polybutadiene, polystyrene, and polyphenylene oxide. This work shows that polymer single crystals embedded in an incompatible polymer matrix can show apparent melting point depressions of up to 5°. This size of depression represents a significant part of that reported for compatible systems.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2277-2286 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The C-13 NMR spectra of partly crystalline poly(phenylacetylene) (PPA) in CDCl3 CCl4 are rather well resolved and the peaks can be matched with those of 1, 3,5-triphenylbenzene. A different, less-well-resolved C-13 spectrum is characteristic of a disordered PPA obtained by heating. We conclude that crystalline PPA has the chain conformation of a cis-cis-oid helix. This interpretation is consistent with the proton NMR spectra and is supported by the fluorescence spectra, which can display two bands, one concluded to be characteristic of the cis-cis-oid conformation, the other of chain conjugation in the disordered polymer. Phase equilibria of PPA in the presence of chloroform were determined and are represented as those of the quasiternary mixture cis-cis-oid helix, disordered polymer, and chloroform.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2299-2301 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2313-2322 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The lateral thermal motion of atoms in an inextensible polymer chain would cause a shortening along the chain direction. This effect could explain the observed negative thermal expansivity α along the chain direction of a polymer crystal. Using this idea, the expansivity α is calculated for a lattice of parallel linear chains. A value of -1.3 × 10-5 K is obtained for chains with a carbon backbone, in good agreement with data for polyethylene.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2323-2336 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The mathematical solution of the following problem is given. Simultaneously with diffusion-controlled mixing of two phases (e.g., gel formation), a third substance diffuses from one of the two pure phases into the other and through the inhomogeneous mixing phase which expands at a rate proportional to the square root of the time. The phases may change their volumes.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2347-2367 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Replicas and thin-section electron microscopic studies were made of fractions of linear polyethylene covering the molecular weight range 2.78 × 104 to 6.0 × 106 for a variety of crystallizing conditions. Lamellar crystallites were found under all circumstances; and the supermolecular structure, or crystalline morphology, is in agreement with that previously reported from an analysis of the small-angle light-scattering patterns of the same samples under similar crystallization conditions. Details of the crystalline microstructure are also described, which range from truncated hollow pyramids which degenerate as the molecular weight or the undercooling are increased. From these results, it is possible to describe the mechanism of formation of polyethylene spherulites.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 18 (1980), S. 2401-2413 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The considerable potential of high resolution time-resolved spectroscopic data for copolymer systems in elucidation of the intramolecular photophysical processes which occur in polymer systems is illustrated. Such information can not be gleaned solely from studies of homopolymers. Kinetic data and time resolved fluorescence spectra of copolymers of 1-vinylnaphthalene and methyl methacrylate indicate that conventional kinetic schemes are inappropriate for the discription of excimer formation in 1-vinylnaphthalene polymers. Evidence is presented for the presence of an emitting species in addition to the expected monomeric and excimeric forms. The nature of this third species is discussed and photophysical kinetic schemes are proposed to describe intramolecular excimer formation in such systems. Kinetic data have been derived for the principle deactivation pathways through investigation of the observed fluorescence decays upon the intrachain concentration of aromatic species.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 13-21 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It is shown that the 13C NMR spectral collapse temperatures Tc reported by Axelson and Mandelkern tend to give a constant ratio of Tc/Tg averaging 1.21 ± 0.05 and independent of Tg or of polymer structure. It is further shown that Tc is not a high-frequency value for Tg because this would require Tc/Tg to decline with increasing Tg. Tc/Tg agrees in numerical value with Tu/Tg, where Tll is the liquid-liquid transition lying above Tg. Direct comparison of Tc and Tu for four polymers PIB, PnBA, atactic PP, and isotactic PMMA shows very close agreement. The various results suggest, but do not prove, that Tc from 13C NMR spectroscopy may be a new, direct measure for Tll. A measured Tc of 233K for linear PE is compatible with a Tg near 195 K (233/195 = 1.19), whereas a Tg of 148 K gives the ratio 233/148 = 1.57, which is outside any value shown in tabulated form.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 49-58 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A theory is presented to account for the effect of the impingement of growing spherulites on their Hv small-angle light scattering patterns. The theory is developed on the basis of results of computer-simulated two-dimensional spherulite growth and calculated scattered intensities. The impingement produces a lowering of the intensity of the scattering maximum and the diminishing of the overall sharpness of the scattering peak. The extent of these effects increases with area fraction of spherulites. A procedure is suggested for determining correction factors that may be applied to intensity data obtained during the course of spherulite crystallization. An interpretation is made of the type of average spherulite size determined from the scattering angle of maximum intensity.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 109-120 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Broad-line 1H NMR spectra of linear polyethylene at temperatures in the α-transition range can be analyzed in terms of contributions from the crystalline and noncrystalline components provided molecular motion in the crystalline region is adequately considered. The spectrum of solid n-C32H66 or n-C44H90 prior to melting is used to take account of the contribution of the crystalline region of the polymer to molecular motions. The temperature dependence of the component distribution in the polymer is briefly discussed for a wide range of temperatures, together with previously reported results at low temperatures. The noncrystalline component is in a rigid glassy state at very low temperatures but with rising temperature it transforms to a mobile glassy state with restricted molecular motion, and transforms partially to the rubbery state at high temperature. The crystalline component remains rigid at low temperature, but some molecular motion is associated with it at higher temperatures in the α-transition range.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 135-141 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The surface composition of TiCl3-based Ziegler - Natta catalysts prepared by various methods was analyzed by ESCA to correlate the total amount of surface titanium with the catalyst activity in propylene polymerization. The ESCA peak ratio (Ti 2P3/2/Cl 2P) of the catalysts was measured to estimate the surface composition. The titanium index defined as the product of the (Ti/Cl peak ratio and surface area) was closely correlated with the catalyst activity in polymerization. This indicates that surface titanium concentration and surface area determine the catalyst activity. It was also found that removal of surface aluminum and chlorine at the catalyst preparation stage results in concentration of titanium at the surface and an increase in surface area.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 181-184 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 185-186 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 245-252 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Adsorption of three copolymers of acrylic acid with N-1-naphthylacrylamide on monodisperse polystyrene latex was studied as a function of pH, ionic strength, and latex concentration. A comparison of the observed adsorptive capacities with predictions based on a model in which the adsorbed polymers retain their shape in solution showed that this model leads to an increasing underestimate as the density of the hydrophobic groups on the polymer is increased and as the pH is reduced.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 281-292 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It is shown that in strictly alternating rigid-flexible copolyamides with the axial ratio x of their rigid elements between 3 and 3.5, lyotropic liquid crystallinity exists in solutions of 25-40% poiymer. For polymers having 4.0 〈 x 〈 4.5, anisotropic solutions appear in the concentration range 15-25%. These axial ratios are substantially smaller than the value of xc = 6.4 predicted by theories for independent rodlike particles, but are in qualitative agreement with recent theoretical calculations taking cognizance of the connection of rodlike elements by flexible residues in the polymer chain. It is further shown that solid solutions of a model compound in an alternating rigid-flexible polymer may be prepared, provided there exists shape and size similarity between the model compound and the polymeric repeat unit.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 321-334 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Optical-absorption, fluorescence, and Raman spectra for solutions, suspensions, and precipitates of poly(1,6-di-p-toluene sulfonoxy-2,4-hexadiyne) in and from nitrobenzene, acetone, and chloroform are presented. These are interpreted in terms of the occurrence of two forms of the polymer chain; a quasicrystalline form with properties close to those of single crystal polymer and a chain-extended form occurring in solution and colloidal particles, with an absorption energy of about 2.5 eV (20,000 cm-1). No evidence is found for the presence of very short polymer chains in partially polymerized monomer at low conversion. The relationship of these results to those for deformed single crystals is briefly discussed.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 361-367 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effect of heterogeneous chlorination of high-density polyethylene on its crystalline regions was investigated by NMR, x-ray diffraction, differential scanning calorimetry, and infrared spectroscopy. Crystallites remained inaccessible to attack by chlorine, even after extensive chlorination, however, their perfection was affected by extensive chlorination of the adjacent amorphous regions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 369-370 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 405-421 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Partitioning of macromolecules between pore and bulk solutions directly affects both equilibrium and transport processes such as exclusion chromatography and movement of solutes through porous media. Because of interactions between macromolecules and the pore wall, the variation of the macromolecule activity with concentration is different inside the pore than in bulk solution. This difference causes a concentration dependence of the distribution coefficient, as reported in experiments involving exclusion chromatography. In order to explain this effect, we develop a model for a concentration-dependent distribution which explicitly accounts for a coupling between pore-macromolecule and macromolecule-macromolecule interactions. Predictions using this model are reported for the case of rigid spherical macromolecules in both cylindrical and slit pores, including both steric (hard sphere-hard wall) and long-range (screened electrostatic) interactions. An important result is the existence of a general correlation between the first order concentration effect and measurable properties of the macromolecule and porous medium.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 449-457 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A difference-spectrum method is used to measure vibrational frequency shifts in mechanically stressed polymers. It is shown that the peak-to-peak height of the difference-spectrum intensity profile is a linear function of small frequency shifts with a slope inversely proportional to the band halfwidth for Lorentzian or Gaussian bands. The method is applied to measure frequency shifts in uniaxially stressed ultraoriented isotactic polypropylene films, using a double beam infrared grating dispersion spectrometer with a nonstressed sample in the reference beam. It is shown that frequency shifts can be measured with an accuracy of better than 0.01 cm-1 using the difference-spectrum method.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 487-497 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The width at half-height of SAXS discrete diffraction peaks has been used to compute the number of polyethylene lamellae in a stack. The dependence of this width on diffraction order reflects the nature and magnitude of lattice fluctuations. Within the literature there have been conflicting reports on this order dependence and hence on the nature of the lattice fluctuations. Previous studies have neglected the effects of instrumental broadening. These present studies show that instrumental effects can account for some 40% of the observed first-order peak width and drastically change the ratio of peak widths as a function of order. These studies, carried out on isothermally grown polyethylene single-crystal mats, also demonstrate the importance of the functions chosen to represent the various broadening factors. A mat was made up consisting of randomly stacked lamella with two distinct fold periods. The scattering from this mixed mat could not be described by either of the prevailing theories.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 531-555 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Several choices of the functions describing the creation and destruction processes of entanglement junctions in the Yamamoto network theory of concentrated polymer solutions have been examined. These choices are simple functions of the extension of the network segments bridging the entanglement points and it is demonstrated that the moments of the distribution function describing the network conformation can be solved for analytically. This has been done for a wide range of two-dimensional flows, both for the steady state and transient start-up and relaxation problems. The macroscopic stress tensor and flow birefringence are calculated and a variety of nonlinear effects are predicted and discussed.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 517-527 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The shear stress σ, two components of birefringence, and extinction angle were measured for a concentrated polystyrene solution in step-shear deformation of magnitude of shear 0.3 ≤ γ ≤ 4.0. The stress-optical coefficient did not depend on either γ or time. The first and the second normal-stress differences v1 and v2 were evaluated with the use of the stress-optical law. Over a certain range of long times, σ could be factored as σ = γh(γ)G(t) and the quantity h(γ) agreed with the prediction of the Doi-Edwards theory based on the de Gennes tube model of entangled polymer chains. At short times the effect of γ on σ/γ was smaller than at long times. The relaxation spectrum became approximately independent of γ at the short-time end of the rubbery plateau region. The ratios v1/σ and v2/v1 were independent of time and were in quantitative agreement with those predicted by the Doi-Edwards theory: v1/σ was equal to γ, v2/v1 was negative, and |v2/v1| decreased with increasing γ.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 557-587 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The results of flow birefringence measurements are reported for polymer solutions of moderate concentration subjected to a wide range of two-dimensional flows. These flows were generated in a four-roll mill which enables one to systematically vary the ratio of the vorticity to the rate of strain in the flow while holding the velocity gradient constant. It is shown that steady-state birefringence data collected over a wide range of flow types can be correlated against the eigenvalue of the velocity gradient tensor, in agreement with criterion for strong and weak flows from model calculations. Transient birefringence measurements in which purely extensional flows were started from rest are also reported. It was observed that the birefringence went through a pronounced overshoot in time for two different polymer/solvent systems. Flow induced increases in the solution turbidity were also observed and the increased turbidity remained constant over a period of many hours after extensional flows were arrested. The birefringence, on the other hand, decayed to zero almost immediately after the flows were stopped. These changes in the turbidity suggest that crystallization of the polymer was occurring. The qualitative results of experiments are compared to recent network model calculations using the theory of Yamamoto for concentrated polymer systems. It is found that this model can predict qualitatively many of the experimental observations if the function describing the breakage of polymer chain entanglements is allowed to depend on the conformation of the polymer segments bridging the entanglements. In particular, this dependency of the entanglement breakage on the conformation of the network segments leads to a predicted overshoot of birefringence when purely extensional flows are started from rest. It is also demonstrated through this model that birefringence data taken over a wide range of flow types can be used to estimate the degree to which the network deforms affinely with the flow field.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 653-665 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: X-ray diffraction patterns were obtained for as-cast and oriented films of poly(γ-benzyl L-glutamate) and a comparison was made of the molecular packing of the α-helices in forms B and C. Form B snowed Bragg reflections on the layer lines as well as on the equator. The spacings were explained by a monoclinic unit cell comprising two chains, with a = 29.06 Å, b = 13 20 Å, c = 27.27 Å α = γ = 90°. and β = 96°. The chains contained in this unit cell and consequently alternating in the crystal have opposite chain directions. Form C showed continuous scattering on the layer lines and reflections on the equator. This form, therefore, is a nematiclike paracrystal in which the packing of α-helices is periodic in the direction lateral to the chain axis (a = 14.8-115.2 Å, b = 14.3-14.8 Å, c = 27 Å, and γ = 118°-120°), but the relative levels of the chains along the chain axes are displaced. The formation of form C may be attributed to random placement of two chains with mutually opposite chain directions.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 631-651 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The carbon-13 NMR linewidth (proton decoupled) of linear and branched polyethylenes crystallized so as to yield different supermolecular structures, as well as a polyethylene oxide sample, have been studied in detail. The purpose has been to assess the different molecular contributions to the linewidth in the completely amorphous polymer as well as in the amorphous regions of the semicrystalline state. These studies on a number of different structures were complemented by both proton-decoupled and dipolar-decoupled magic-angle spinning experiments on a particular sample, as well as frequency dependence studies. It is found that the abnormally broad resonance lines previously reported for the molten polymer can be significantly reduced by adopting appropriate methods of sample preparation and magnetic-field homogenization at each temperature. Relatively narrow lines result which can be interpreted in a conventional manner. In the semicrystalline state, the resonance lines are relatively broad and are shown to be morphology dependent. Specific contributions and their temperature dependence are discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 689-701 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Molecular relaxations of polyesters containing C5-C15 rings in the main chain have been studied by DSC, dielectric dispersion, and NMR. Results are discussed in relation to the size and mobility of the rings. The Tg or α-relaxation peak moves to higher temperature with an increase in the ring size from C5 to C12, but the effect is accompanied by an even-odd alternation with ring size. The β relaxations in dielectric dispersion reflect local-mode motion of ester groups and are affected by steric interactions with the rings. Motions of the ring methylenes of C12 and C15 ring units are detected below Tg by broad-line NMR.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 731-741 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A computer program for modeling three-dimensional spherulite nucleation, growth, and impingement was elaborated. The Monte Carlo method was used to determine the degree of conversion and calculate the volume of the spherulites. Athermal, thermal, and mixed types of nucleation were tested. The experimental Avrami exponent agrees with the predictions for athermal and thermal nucleation while for mixed nucleation a nonintegral exponent is characteristic. The spherulite size distributions are very different from athermal and thermal nucleations. An intermediate pattern of distribution is proper for the mixed type of nucleation. The boundaries of the largest spherulites from thermal and mixed nucleation are concave while those of the smallest spherulites are convex.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 749-761 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Correlations of the stress-intensity factor K with crack speed a have been obtained for environmental stress cracking (ESC) of a series of low-density polyethylenes in detergent. In the majority of the materials, the crack speed increases initially with increasing K, then becomes constant, and finally starts decreasing. The ESC resistance increases with increasing molecular weight and, in general, the quenched materials show greater ESC resistance than slowly cooled ones. The crack propagation results agree well with the ESC model of Williams. Attempts have also been made to understand the micromechanics of ESC failure from a combined approach of K, the crack tip characteristics, and the fracture surface appearance. The roughness of the fracture surface increases with increasing K.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 803-814 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The NMR spin-spin relaxation (T2) spectra of high-density polyethylene (PE) has been investigated over a wide range of temperatures, both in the solid and molten states. Previous work in these laboratories has shown that the T2 relaxation spectrum of molten polyethylene differs from that of other polymers studied in that (a) it cannot be decomposed into two relaxation spectra (T2S and T2L) and (b) there is some evidence of a memory effect. This paper attempts to elucidate these observations, and compare them with the spin-spin relaxation of polyethylene at lower temperatures. In the solid state, the T2 decay comprises both a Gaussian distribution for the crystalline region, and an exponential decay for the amorphous component. The effects of crystallization conditions and of temperature were determined. In the molten state the T2 decay is more complex, but can be resolved into three exponentials. The longest (T2L) component arises as expected from the most mobile, low molecular weight fraction. The T2S component is due to an entangled but mobile network, as in other polymers. In addition, a short relaxation component T2X is observed, which is influenced by previous crystallinity and the processing history of the material, and is ascribed to some vestigial degree of structure in the molten phase.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 837-847 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polymerization of p-acryloyloxybenzoic acid by heating on a hot stage was previously reported to lead to a lyotropic mesophase. Using optical microscopy, thermal analysis, and infrared analysis, it was shown that this mesophase involves oligomers of poly(p-oxybenzoate) formed from the monomer by ester interchange through internal acidolysis.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 877-888 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Ultradrawing of films of high-molecular-weight polyethylene (M̄w = 1.5 × 106) produced by gelation crystallization from solution is discussed. The influence of the initial polymer volume fraction (φ) on the maximum draw ratio (λmax) of the dried films is examined in the temperature region from 90-130°C. The results can be described very well by the relation λmax = λmax1 φ-1/2 where λmax1 is the (temperature-dependent) maximum draw ratio of the melt-crystallized film. An attempt is made to discuss the marked influence of the initial polymer volume fraction on λmax in terms of the deformation of a network with entanglements acting as semipermanent crosslinks.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 863-875 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The persistence length of poly(terephthaloyl p-amino benzhydrazide) (X-500) in dimethyl sulfoxide (DMSO) has been determined from intrinsic viscosities measured for several whole-polymer samples. An approximate correction is applied for excluded volume effects, and these corrected values are fitted using the viscosity treatments of Yamakawa and Fujii and of Eizner and Ptitsyn. Both give for the persistence length of X-500 values in the range 30-35 Å. Revised treatment of our previous light scattering data for the same polymer yields 49 Å for the persistence length. Thus the chain extension of X-500 falls between those of para-linked polyamides and those of typical freely coiling macromolecules. Phase diagram studies indicate the solubility of X-500 in DMSO decreases with rising temperature, and can be increased by the addition of LiCl. No anisotropic phase is found in DMSO at the highest volume fraction of polymer, v2 = 0.19, which can be obtained with 4 g/dl LiCl. The critical concentration of X-500 needed for the appearance of the anisotropic phase depends upon solvent since Morgan reported an anisotropic phase for this polymer in 100% H2SO4 when v2 ≈ 0.13.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 921-932 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The flow field in an electrically driven jet has been examined and quantitatively analyzed. Using a model fluid, the nature of the streamlines and magnitude of the stream velocities were investigated with the aid of tracer particle photography. It was found that the velocity field is not purely extensional, but contains rotational components as well. Furthermore, the only portion of the jet completely free of any rotational component is the region about the symmetry axis. The extensional strain rate along the symmetry axis increases rapidly with the applied electric field intensity and can attain values in excess of 50 sec-1. This suggests that it might be possible to draw continuous oriented fibers from polymer melts by this technique if the jet can be operated at sufficiently high electric field intensity.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 983-989 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A cage model has been presented to describe the kinetics of recombination of radicals in solid polymer. The theory includes Torrey's treatment for jump diffusion and radiative boundary condition in the diffusion equation to account for the hindrance to the diffusion of macroradicals and the finite cage process of recombination reaction, respectively. The result has been applied to the interpretation of data on the decay of allyl radical in irradiated polyethylene.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 991-1002 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Dielectric measurements between -50 and 60°C have been made on isotropic and oriented samples of poly(chlorotrifluoroethylene) with draw ratios λ of 1 to 3.5 at frequencies ranging from 30 Hz to 1 MHz. For the oriented samples, the dielectric loss has been measured with the electric field normal (ε⊥″) and parallel (ε∥″) to the draw direction. At low frequency (say 60 Hz) the loss data for the oriented samples reveal two peaks at 25 and -5°C, which are associated with the amorphous (γa) and the crystalline (γc) relaxations, respectively. Analysis of these data using a two-phase model yields values for the amorphous orientation function fa which are only about 25 to 60% of those for the crystalline orientation function fc. Upon annealing, the anisotropy ε⊥″/ε∥″ at the γa peak decreases significantly while that at the γc peak remains largely unchanged. This implies a roughly unaltered fc and a large decrease in fa, which is consistent with the results of wide-angle x-ray diffraction and birefringence measurements.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1011-1013 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1047-1053 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Work on the surface-growth method of producing blend films from mixed solutions of two polymers has exposed a random fluctuation in both growth rate and composition of the blend film with time of deposition. The effects are explained by heterogeneous separation of the two polymer components in the solution induced by the stirring action of the rotor of the Couette apparatus used. The solution is thus converted to a colloidal sol which on cooling forms a gel which exhibits syneresis at room temperature. The sol-to-gel transition is thermally reversible.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1033-1046 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The variable-contrast method in small-angle neutron scattering has been applied to a study of the conformation of polystyrene-polyisoprene block copolymers in dilute solution. The experimental results reveal no intramolecular segregation effect in dilute solutions in toluene and cyclohexane.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1081-1105 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Films of chitosan, prepared by different fabrication processes, were examined at several structural levels, from the molecular to the macroscopic. This revealed the presence of polymorphic crystal forms, which varied with film treatment. Similarly, morphological structures varying from spherulites to rods were formed, depending on film processing conditions. The effect of structure on the mechanical properties, as well as the orientability of the films, were also investigated.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1141-1149 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An electron spin resonance (ESR) study has been made of radicals trapped in polyisobutylene irradiated at 77 K. It is concluded that only the —C(Me)2—CH— radical remains after heat treatment above 213 K. This radical shows a very sharp doublet ESR spectrum with hyperfine splitting of about 2.2 mT. A broad doublet ESR spectrum observed without warming, which was previously assigned as —C(Me)2—CH—is explained as a mixture of a doublet and a triplet due to the —C(Me)2—CH— and radicals. γ-irradiation at 77 K produces these major radical components and other carbon radicals as minor species. It has also been found that a conversion of other radicals into —C(Me)2—CH—occurs without decay on annealing below 183 K. Heating in the range 183-213 K causes both conversion and decay of the radicals. On annealing above 213 K, only decay occurs. The ESR spectra of polyisobutylene radicals are easily saturated by microwave power even at 1.6 μW. The mechanism of radiolysis for polyisobutylene is briefly discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1163-1166 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1173-1176 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1199-1209 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Partial molar heats of mixing ΔH1∞ and Flory-Huggins χ parameters have been determined for a series of polar and nonpolar organic probes in the polymer systems polychloroprene, poly(butadiene-acrylonitrile) (34 wt. % acrylonitrile), poly(ethylene-vinylacetate) (40 wt. % vinylacetate) and cis-1,4-polybutadiene in the range 65-85°C. Using the Flory-Huggins χ parameters, infinite-dilution solubility parameters δ2∞ were calculated for the polymers at 75°C to be 8.8 ± 0.2 for polychloroprene 10.0 ± 0.3 for poly(butadiene-acrylonitrile), 8.3 ± 0.2 for poly(ethylene-vinylacetate) and 7.9 ± 0.1 for polybutadiene. These δ2∞ values are in good agreement with literature δ2 values. δ2∞ values were also calculated using only polar or nonpolar probes. The change in δ2∞ as the set of probes changed was negligible, leading to the conclusion that Hanson's three-dimensional solubility parameter concept may not be applicable to the infinite-dilution case.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1231-1236 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Mixtures of trifluoroacetic acid (TFA)-1,2-dichloroethane (1,2-DCE); TFA-dichloromethane (CH2Cl2); and TFA-trichloromethane (CHCl3) are excellent cellulose solvents at room temperature. TFA-1,2-DCE and TFA-CH2Cl2 are superior to pure TFA. Lyotropic cellulose mesophases were obtained in (20% w/v) solutions of cellulose in these solvent mixtures. The optical and optical rotatory powers of the solutions suggest that the lyotropic mesophase of cellulose is cholesteric. This implies that cellulose molecules are arranged in helical form in these solvent systems.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1269-1272 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1277-1279 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1280-1280 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1325-1331 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The relation between the thermal behavior of extended-chain crystals (ECCs) of polyethylene and the phase transitions, i.e., orthorhombic ↔ hexagonal ↔ melt, of polyethylene at high pressures above about 400 MPa has been studied by high-pressure differential thermal analysis (DTA), and with a high-pressure and high-temperature x-ray diffraction apparatus equipped with a position-sensitive proportional counter measuring system. The original sample used in this study consists mainly of two kinds of ECC, which we designate as “ordinary extended-chain” crystals (OECCs) and “highly-extended-chain” crystals (HECCs). Experimental results at pressures below 300 MPa substantiate the results previously reported: i.e., the phase diagram indicating the relation between the melting temperatures and pressure for the OECCs and HECCs can be determined for pressures up to 500 MPa.In heating at pressures above about 500 MPa, the peak intensity of the (100) reflection of the hexagonal structure decreases in two stages with increasing temperature. The phenomenon corresponds to the thermal behavior determined by high-pressure DTA in which two small endothermic peaks can be observed at temperatures above that of the crystal transition evidenced by the strong peak. This phenomenon suggests melting in two stages of hexagonal structures with different thermal stabilities, and that the change at higher temperature may be due to fusion of the hexagonal phase annealed either below or above the transition temperature.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1365-1369 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: X-ray diffraction, thermally stimulated depolarization, and piezoelectric current measurements have been carried out on uniaxially stretched poly(vinylidene fluoride) film, corona poled both negatively and positively at room temperature and at 90°C. Corona poling at elevated temperature considerably enhances the piezoelectric constant and is a more efficient way of charging the film than conventional thermal poling. Advantages over the latter are discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 1377-1383 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An acrylonitrile-styrene copolymer having 51.4 wt % acrylonitrile content was fractionated using dimethylformamide and a toluene-n-propanol mixture as solvent and nonsolvent, respectively. From characterization of the fractions, it is shown that the copolymer was fractionated principally in accordance with composition. The weight distribution curve of the copolymer was expressed as a function of both molecular weight and chemical composition on a two-dimensional contour map. The same plotting technique was applied to a copolymer having nearly the azeotropic composition.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...